HORSE
HEALTH LINES
SPRING 2005
A NEW ERA IN HORSE HEALTH
COLLEGE EXPANSION BRINGS NEW TECHNOLOGY, SERVICES
AND RESEARCH TO HORSES
PROMISING POTENTIALS
SCIENTISTS TEST POTENTIAL OF NEW EQUINE HEALTH
RESEARCH STUDIES
EQUINE LINK TO ISLAND FUNGUS
VANCOUVER ISLAND HORSES EXPOSED TO
CRYPTOCOCCUS GATTII
SKIN-DEEP ATTRACTION
EXPLORING A SPECIALIST’S PASSION FOR
VETERINARY DERMATOLOGY
GOLDEN YEARS
A TRIBUTE TO HORSE HEALTH CHAMPION
GEORGE GOLDEN
EQUINE DENTISTRY:
THE FUTURE IS
WIDE OPEN
RECENT RESEARCH HAS LITERALLY OPENED THE HORSE’S MOUTH
TO THE VETERINARY PROFESSION. “IF ANYONE IS INTERESTED
IN LEARNING MORE ABOUT EQUINE DENTISTRY, THERE’S NO
EXCUSE ANYMORE. IT’S ALL THERE,” SAYS SURGICAL RESIDENT
DR. JAMES CARMALT (ABOVE). SEE PAGES 8 AND 9 FOR MORE
DETAILS.
A publication of the Equine Health Research Fund, Western College of Veterinary Medicine, University of Saskatchewan.
A New Era in
HORSE
H E A LT H
W
ith the Western College of Veterinary Medicine’s $43-million
transformation now underway, bringing horses to the Veterinary
Teaching Hospital calls for dexterity in the parking lot. “We’re
starting to deal with some traffic challenges in our animal receiving area,”
says Dr. David Wilson, head of WCVM’s Large Animal Clinical Sciences
department. “As larger equipment moves in, clients may have to wait before
unloading their animals.”
But as Wilson points out, these traffic challenges won’t affect the quality
of clinical services. And in the long run, any short-term disruptions are well
worth the benefits that all western Canadians — including horse enthusiasts
— will gain once the College completes the major expansion and upgrade of
its facilities in 2008.
To reach that point, construction crews will add more than 11,000
square metres to the College’s original 25,290-square-metre building and
renovate nearly 6,900 square metres of existing facilities during the next
three years. Plans involve more than two dozen “sub-projects” including a
two-storey addition to the veterinary teaching hospital, a food animal clinical
teaching facility, consolidated research animal housing, “multi-use” research
laboratories and an upgraded diagnostic services area.
“Mixed into that, we’re planning construction in phases since our
teaching, research, clinics and diagnostic laboratories must continue
operating throughout the project,” explains WCVM Dean Dr. Charles
Rhodes.
He adds that the federal government has already provided $22.2 million
in funding for the project, and the Saskatchewan government committed $15
million in November 2004. WCVM will raise the final $5 million through its
Veterinary Teaching Hospital capital campaign.
While three years of construction is posing logistical challenges,
hospital director Dr. Stan Rubin confirms that it’s “business as usual.” Regular
services will continue even during major renovations to the hospital’s
surgical, examination and animal care facilities in its Small Animal and Large
Animal Clinics.
The key is planning construction in phases so regular hospital services
continue operating, explains Rubin, a member of the College’s hospital
expansion committee. The committee, which is chaired by WCVM
veterinary ophthalmologist Dr. Bruce Grahn, is one of the College’s four
planning teams. Directed by Rhodes, all of the committees have been
working closely with the project architect (AODBT), the project manager
(UMA Engineering) and the construction manager (Graham Construction)
to plan the College’s renovations in phases.
2
Horse Health Lines • Spring 2005
Construction crews will add more than
11,000 square metres to the College’s
original 25,290-square-metre building and
renovate nearly 6,900 square metres of
existing facilities during
the next three years.
For WCVM’s large animal clients, noticeable changes include:
• a safer chute complex in the large animal handling area and an expanded
“stocks” area to accommodate additional equine patients.
• a modernized surgical “core area” with more spacious suites for large animal
surgery. Renovated facilities include a surgery room dedicated to performing
surgery in standing, sedated cows.
• improved biosecurity throughout the Veterinary Teaching Hospital
and improvements to isolation facilities to reduce the spread of infection.
Above: Equine surgical specialists will have more room to work in the Large Animal
Clinic’s renovated surgical suites. At right: This architect’s rendering shows the
Veterinary Teaching Hospital’s two-storey addition, the remodelled Large Animal
Clinic entrance and additional garage space for the hospital’s ambulatory service.
Extensive renovations will allow staff to shut
down a particular ward from the rest of the
hospital in case of a biosecurity issue. Traffic
patterns will be altered between equine and
bovine wards so humans and animals can’t walk
directly between wards. Remodelled wards will
also have stalls equipped with flooring materials
that can be thoroughly cleaned and disinfected.
Although most of the isolation units are
already on the building’s periphery, Wilson says
the expansion project will provide additional
space for calf isolation and a separate anteroom
for each isolation unit. Health care workers can
use these rooms to dress and remove special
protective clothing before returning to the
hospital.
• a renovated large animal reception, a new
field service office and storage room, and some
client consultation rooms. Construction crews
will also build additional garage space for the
Veterinary Teaching Hospital’s ambulatory
service.
With final approvals from the University
of Saskatchewan and Environment Canada
in place, construction workers moved on site
in October 2004. As Rhodes explains, the
crews are using a staggered, “construction
management process” that allows planning
to continue on one area of the project while
construction is fully underway on another area.
“It’s more time efficient, it’s easier to stay on
budget, and if we have late-stage changes, it’s
more flexible than the traditional, single-tender
approach.”
Just as construction plans need to be
flexible in the next three years, the College’s
staff, clinicians and students are quickly
learning to adapt to a variety of environments,
situations and new roles — such as the
temporary job of traffic cop in the clinic’s
parking lot.
“These problems are surmountable,
and it’s going to be more of a temporary
inconvenience than anything,” assures Wilson.
“And when everything is finished, we’ll
definitely be competitive with any veterinary
teaching, research and clinical facility in North
America.”
Visit www.wcvm.com to learn
about the College’s expansion
project.
From the Dean’s Desk
This issue of Horse Health Lines includes a tribute to George Golden — an Alberta
horseman who recognized the long-term value of supporting equine health research and training
at the Western College of Veterinary Medicine. Besides helping to establish the Equine Health
Research Fund, George was one of WCVM’s earliest advocates in the horse industry.
More than three decades after George made his first contribution to WCVM, thousands of
horse owners and veterinarians continue to follow his example. That grassroots support has
enabled our faculty and graduate students to forge ahead in many aspects of horse health
research. It has also allowed WCVM to generate a network of equine specialists who continue to
improve health care for horses around the world.
Now, the College’s $43-million expansion will provide WCVM’s equine research and
training programs with the facilities and resources they need to produce even more research,
more specialists and more services for horse owners.
New laboratories will provide our students, faculty and staff with the facilities and tools
they need to conduct advanced research. An expanded Veterinary Teaching Hospital will
also increase the number of specialized services we offer to horse owners and referring
veterinarians. In turn, this will provide students with a larger and more diverse caseload that
enriches their education and provides them with solid experience they can take into the field.
As we grow, so will the Fund — and that’s why it’s important for you to continue your
support of the College’s horse health programs. I’m also asking you to consider making a
special contribution to our Veterinary Teaching Hospital capital campaign. While the federal
government and the province of Saskatchewan have committed more than $37 million to
the entire expansion, we must raise the final $5 million from WCVM’s alumni, friends and
stakeholders before we can complete this project.
We can accomplish several goals with your support. By expanding WCVM, we can
strengthen the College’s role as Western Canada’s centre for veterinary education, research and
expertise. We can continue being an integral part of national networks for animal and public
health. And we can provide our partners — including the Equine Health Research Fund — with
the facilities and resources needed to enhance WCVM’s animal health research and training
programs.
Ultimately, this expansion project will significantly increase the Equine Health Research
Fund’s potential for improving the quality of horse health care — a goal that George Golden and
the rest of the Fund’s founders envisioned nearly 30 years ago.
These are exciting times for the College, and we look forward to having you join in
our plans for expanding your world of veterinary medicine. You can help by continuing your
support of the Equine Health Research Fund — and by considering a special contribution to the
Veterinary Teaching Hospital capital campaign this year.
You’ll find all of the information you need to make both donations on the enclosed tear
out cards or visit www.wcvm.com/supportus. If you have any questions about EHRF or the VTH
capital campaign, please contact Joanne Wurmlinger, WCVM’s development officer, at 306966-7450 (joanne.wurmlinger@usask.ca).
Enjoy the rest of Horse Health Lines — and thank you for investing in the future of
veterinary medicine.
Dr. Charles Rhodes, Dean, WCVM
Promising
POTENTIALS
PROMISING (adj.): likely to be successful or to turn out well.
POTENTIAL (noun): the capacity or ability for future
development or achievement.
These two words are a fitting description for the 200506 lineup of research projects supported by the Western
College of Veterinary Medicine’s Equine Health Research
Fund. Worth just over $93,000, discoveries stemming
from these five promising studies have the potential to
save millions of dollars in health costs for horse owners
around the world.
Can lidocaine prevent intestinal damage after colic surgery?
Drs. Ryan Shoemaker, David Wilson, Andy Allen and Jenny Kelly
Horses that undergo surgery for small intestine-related colic have a
low survival rate. Many suffer postoperative complications like ileus (lack
of movement in the intestine), abdominal adhesions or systemic illness.
The culprit? Overzealous neutrophils. These primary white blood cells
infiltrate the small intestine and potentially cause post-surgery complications
to develop.
Scientists have proven that intravenous lidocaine (a local anesthetic)
decreases the migration and adverse actions of neutrophils on tissue in
humans and other species. In the next 14 months, two teams of WCVM
surgical specialists will simultaneously perform experimental surgical
procedures on pairs of anesthetized horses (nine pairs altogether). Their
goal is to mimic naturally occurring small intestine strangulation and bowel
distention in experimental models.
Once the teams have recreated this scenario, each horse will receive
intravenous infusions of lidocaine or saline solution for the remainder of the
experiment. If tissue samples show that continuous lidocaine infusions during
surgery reduce neutrophil accumulation and activation in patients’ small
intestines, surgical specialists will gain a new tool in preventing complications
after colic surgery.
Bone Scans Reduce
GUESSWORK
As part of its expansion plans, WCVM will bring one of the most
useful tools for diagnosing difficult equine lameness cases to its
Veterinary Teaching Hospital.
Nuclear scintigraphy — or bone scanning — detects increased
bone turnover (or bone remodelling) that’s associated with stress
fractures, arthritis, bone injuries and infections. “If you take 100 lame
horses, we can usually sort out the problems in 80 of those cases. The
remaining 20 per cent will be horses with unidentifiable lamenesses,”
explains equine surgical specialist Dr. David Wilson.
“But with nuclear scintigraphy, we can make a definitive diagnosis
in about 18 of those 20 tough cases. Having the technology will increase
our success rate in correctly diagnosing equine lameness.”
Can we treat heaves by removing pro-inflammatory cells?
Drs. Baljit Singh and Hugh Townsend
Recurrent airway disease (heaves) is a chronic respiratory disease that
impairs lung function and compromises performance in mature horses. Besides
reducing a horse’s exposure to allergens, bronchodilators and corticosteroids
can help to treat the disease symptoms — but long-term corticosteroid use
isn’t recommended.
As an alternative, Drs. Baljit Singh and Hugh Townsend will test the
potential for “knocking out” pulmonary intravascular macrophages (PIMs)
— pro-inflammatory cells that may play a central role in heaves development.
Previous studies have shown that depleting a body’s supply of these inflammatory molecules will neutralize endotoxin-induced pulmonary arterial
hypertension and lung inflammation.
To test the potential role of PIMs in heaves, the research team will
assemble five normal horses and another five horses diagnosed with heaves.
Both groups will then undergo a PIM-depleting protocol. Researchers will use
bronchoalveolar lavages and lung biopsies to examine lung responses of all
horses before and after the process. They’ll also conduct clinical examinations
of all horses while they’re kept in a clean environment for one month.
After 30 days, the research team will move all of the horses to a heavesprovoking environment, then take further lung samples. If horses diagnosed
EHRF-supported research includes a study looking at whether R. equi-susceptible
foals have impaired immunity (above), a surgical trial to test drug therapy that may
prevent complications after colic surgery (right, top) and an in-depth investigation of
congenital stationary night blindness in Appaloosa horses (right, centre).
Besides horses, WCVM’s newest diagnostic technology will be
used on other large animals and small animal patients. The College will
purchase the specialized equipment once renovations are completed
in the areas that will house nuclear scintigraphy and the CT (computed
tomography) scanner — another diagnostic tool that WCVM installed in
2004.
During a bone scan, a medical imaging specialist injects a
radioisotope (a radioactive compound called Technetium 99 combined
with MDP, a bone seeking agent) into a horse’s vein. After circulating
through the bloodstream, the radiopharmaceutical concentrates in the
bone — especially where there’s increased metabolic activity. When
the horse stands in front of a gamma camera, the device shoots signals
back to a computer, and it develops a scintigram highlighting “hot spots”
of increased bone remodelling.
Veterinarians regularly use nuclear scintigraphy to diagnose difficult
lameness problems like incomplete fractures of the cannon bone,
damage to the high suspensory ligament and low-grade arthritis. More
with heaves show inhibition of inflammation following
exposure to allergens, this project may lay the foundation
for developing a new treatment method for heaves.
Can genetics help identify high-risk patients for
endotoxemia?
Dr. Katharina Lohmann
Endotoxemia (endotoxin in the bloodstream) is a
life-threatening complication of many common equine
diseases including colic, endometritis (inflammation of the
uterus) and pleuropneumonia. While the ability to mount
an inflammatory response to endotoxin is part of the body’s
natural defense against infection, overwhelming amounts
can stimulate a systemic (generalized) inflammatory
reaction that may result in complications like laminitis, a
permanent loss of athletic ability or even death.
Based on studies in humans and other species, it’s
possible that gene sequence variations among individual
horses — as detected by the identification of certain single
nucleotide polymorphisms (SNP) — may be associated
with differences in the immune response to endotoxin.
As a result, finding these SNPs may help identify horses
that have an increased susceptibility to the effects of
endotoxemia.
While no one has characterized the genetic factors
influencing the response to endotoxin in horses, Dr.
Katharina Lohmann has identified SNP in equine genes
encoding innate immune sensors like Toll like receptor 4
(TLR4) and MD-2, as well as in inflammatory mediators
such as equine tumour necrosis factor a (TNFa).
This year, Lohmann plans to build on these
preliminary findings. Using a large group of 50 horses, the scientist will evaluate
the animals’ gene sequences to estimate the prevalence of SNP in the equine
population and investigate their association with endotoxin-induced TNFa
production in vitro.
This study will be the first step toward characterizing genetic risk factors
for endotoxemia in horses, and ultimately, could allow clinicians to use
preventive therapy on high-risk patients. It may also lead to individualized
therapy, more accurate prognoses and more informed breeding strategies for
the horse industry.
recently, it’s been used to identify incomplete pelvic fractures, navicular
disease, abnormal teeth and for measuring the speed of transport
through the gastrointestinal tract.
Nuclear scintigraphy usually isn’t the first diagnostic tool that
equine specialists use, but if all other imaging methods fail, a bone scan
can refocus the diagnostic process. “For example, once a hot spot is
identified over a tooth, that stimulates people to reexamine a radiograph
or to take another X-ray. In our case at WCVM, we may even decide to
perform a CT scan to get a better idea of what’s going on,” explains Wilson.
In the past, western Canadian horse owners travelled to the
University of Minnesota or Washington State University to access nuclear
scintigraphy. The technology is now available at Moore & Company,
an equine veterinary clinic north of Calgary, Alta., and accessibility will
be even better once WCVM offers the diagnostic service: “We see lots
of cases where it would help to make a definitive diagnosis. Once we
have the technology in place, this will be the next step in most of those
undiagnosed cases,” says Wilson.
Is CSNB linked to the gene responsible for
leopard Appaloosas?
Drs. Lynne Sandmeyer, Bruce Grahn and Carrie Breaux
Congenital stationary night blindness (CSNB) is a
hereditary condition in Appaloosa horses. Affected
animals can have visual problems ranging from reduced
vision to complete blindness in dim light, or even
reduced vision in normal light. While the disease’s
inheritance pattern is still unknown, reports from
breeders suggest that clinical signs of CSNB are more
common in Appaloosas with the homozygous leopard
complex (Lp) or leopard coat patterns.
Geneticists recently mapped Lp to a small region
on equine chromosome 1. One potential candidate gene
for Lp is the pink eyed dilution gene that’s responsible
for oculocutaneous albinism in humans — an hereditary
disorder characterized by a deficiency of the pigment
melanin in the eyes, skin and hair. Affected people have
structural abnormalities of the optic nerves and optic
tracts of the brain. Scientists hypothesize that similar
abnormalities cause CSNB in Appaloosas.
During the next two years, veterinary
ophthalmologists will conduct an in-depth investigation
of the clinical, electroretinography and structural
characteristics of CSNB in Appaloosas. As well, the
research team hopes to confirm the disease’s inheritance
pattern. If their findings confirm that CSNB is linked
to the gene responsible for leopard coat patterns, then
future investigations will focus on finding the gene
responsible for CSNB in the breed. This information
could also lead to the eventual development of gene therapy for this
condition.
Do R. equi-susceptible foals have low expression levels of
antimicrobial peptides?
Drs. Hugh Townsend, Marianela Lopez, Volker Gerdts and Sam Attah-Poku
Rhodococcus equi is a soil-borne, Gram-positive bacterium that causes
rhodococcal pneumonia in young foals. The bacteria concerns horse breeders
since prevalence and case fatality rates are high on endemic farms. As well,
available therapies are expensive and not always effective.
Scientists still don’t know why young foals are more susceptible to
R. equi, but evidence supports the theory that immaturity of the immune
system in neonates is responsible for this susceptibility.
As part of the innate immune system, antimicrobial peptides are
molecules capable of eliminating a broad spectrum of bacteria, fungi and
parasites. Major components of this peptide-base defense system —
ß-defensins and cathelicidins — have been identified in the horse, and they
have shown antimicrobial properties in vitro.
During the next year, a team of researchers at WCVM and at the
Vaccine and Infectious Disease Organization will determine whether these
molecules are able to eliminate R. equi. The team will also investigate
whether low expression levels of these antimicrobial peptides in the mucosal
surfaces are associated with the foals’ susceptibility to R. equi infection.
By gaining a better understanding of the immunologic mechanisms
associated with the increased susceptibility of individual foals to R. equi
infection, scientists can develop more effective ways to control and prevent
this devastating disease.
Western College of Veterinary Medicine 5
I
n October 2003, Dr. Colleen
Duncan of the Western
College of Veterinary Medicine
had just finished a summer-long
investigation into the spread of
cryptococcosis among cats and
dogs on Vancouver Island. After
concentrating on small animals
for most of the year, the graduate
student was putting the final
touches on a new research proposal
that targeted another potential
victim of the rare fungal disease:
the thousands of horses living on
the Island.
Then she heard the news:
for the first time, diagnostic
bacteriologists had isolated
Cryptococcus gattii — the same
fungus that had caused cryptococcal
disease in hundreds of pets, wild
animals and humans — from an
Island horse with pneumonia.
“It made us ask the question:
if we look hard enough, will we
find the cryptococcal infection in
more horses?” says Duncan, who
helped to perform the post mortem
examination on the Cryptococcusinfected horse. The case also
became part of the successful
Equine Health Research Fund
proposal that she and her graduate
studies supervisors — Dr. John Campbell of WCVM and Dr. Craig Stephen of
the Centre for Coastal Health in Nanaimo, B.C. — submitted in November
2003.
While it was the first time that C. gattii had been identified in a horse
on the Island, it was only one of many cases included in the disease outbreak
that began in 1999. Since then, 101 humans and more than 200 small
animals have fallen ill with a unique version of cryptococcosis that can cause
upper respiratory infection, acute neurological disease and even death. So far,
four humans have died from cryptococcal disease while more than half of the
pets diagnosed with C. gattii have died or have been euthanized.
Based on the number of cases and the involvement of multiple species,
researchers describe the Island outbreak as an unprecedented emergence of
C. gattii. In December 2004, the U.S. Department of Agriculture’s Center for
Emerging Issues issued a notice about Vancouver Island’s C. gattii outbreak,
citing that “the emergence of this ‘tropical’ fungus and its ability to colonize
on Vancouver Island stresses the importance of worldwide monitoring of
its distribution. Particular focus should be given to those areas that have
climactic and ecological attributes similar to eastern Vancouver Island.”
Cryptococcal disease isn’t new to the Island, but this latest outbreak
is different than the disease’s classic form. “First off, we’re seeing a lot
more cases as well as a full spectrum of cases. Secondly, all were clustered
in a region on the east coast of Vancouver Island,” explains Stephen, who
conducted a case control study
involving 36 companion animal
patients from local veterinary
clinics in 2001.
His findings helped him and
scientists at the British Columbia
Centre for Disease Control
recognize that most of the human
and animal cases were part of a
larger “cluster” near Parksville and
Rathtrevor Beach Provincial Park
on the Island’s east side.
The researchers eventually
confirmed that all of the cases,
which involved healthy people
and animals, were caused by C.
gattii — formerly classified as
the gattii variety of Cryptococcus
neoformans. This tropical strain
of the fungus has been detected
in soil, air and tree samples taken
from areas in the coastal Douglas
fir region of Vancouver Island.
These areas became target
zones for Duncan as she began her
EHRF-supported study in May
2004. Local equine practitioners
helped her compile a list of
clients’ horses living within a
10-kilometre radius of fungal “hot
spots” identified by environmental
scientists from the University of
British Columbia.
During July and August, Duncan collected superficial nasal swabs and
a number of blood samples from 260 horses living within the targeted zones.
She also gathered details about horses’ ages, health problems, amount of time
spent outdoors and the length of time the animals had lived on owners’ farms
as well as on Vancouver Island.
While all equine blood samples tested negative for Cryptococcus
organisms, laboratory technicians isolated the fungus in nasal swabs from four
horses involved in the study. All of the animals lived near the community of
Duncan, B.C., where human health officials have reported clinical cases of
cryptococcosis and where researchers have identified subclinical exposure or
infection in small animals and wildlife.
“Finding Cryptococcus organisms in the horses’ noses but not in their
blood suggests that these animals have been exposed to the fungus and that
there’s a potentially higher level of the organism — plus a potentially higher
exposure level — in that area,” explains Duncan. “That’s supported by
findings in our small animal research and the wildlife sampling we conducted
while we were testing horses.”
When Duncan conducted a similar survey on 300 companion animal
patients in 2003, she found that about two per cent of the pets tested positive
for the fungus while showing no signs of the disease. In 2004, Cryptococcus
organisms were found in nasal swabs taken from two grey squirrels living wild
in the area near the sub-clinical horses.
Island Fungus Makes
EQUINE CONTACT
6
Horse Health Lines • Spring 2005
Horses on Vancouver Island may not
be developing the clinical signs of
cryptococcosis, but an epidemiological
study confirms that the region’s horses
are being exposed to Cryptococcus
gattii — the same strain of fungus at
the centre of an unprecedented disease
emergence.
Veterinarians haven’t identified any further clinical
cases of equine cryptococcosis since 2003, and the fungus
doesn’t appear to be as much of a threat to local horses as
it is to companion animals and humans. However, from an
epidemiologist’s perspective, the Island’s horses are still valuable
information sources since they spend much of their lives
outdoors and are “very representative” of the environment,
explains Duncan.
Based on her 2003 companion animal study, Duncan
and her colleagues concluded that where an environmental
organism is not uniformly present everywhere in a region’s
environment, risk is increased if disruptions — such as logging
or commercial soil disruption — redistribute the organism from
its environmental niche. Increased levels of travel or activity in
the Island’s “hot spots” for C. gattii also boost the likelihood of
encountering the organism.
“Compared to other areas on the Island, UBC researchers
have found higher concentrations of Cryptococcus organisms in
environmental tests taken in the Duncan area — information
that was confirmed by our findings in horses,” says Duncan, now
a PhD student at Colorado State University.
“We’re not saying that everyone should go around
swabbing horses’ noses, but if the organism is isolated from an
animal, we know the source is the environment. And if the
animal doesn’t travel, we know the source of the fungus is in the
immediate environment.”
It’s one more way that veterinary research has helped
human medical scientists understand this unique spread of
cryptococcosis, says Duncan, who worked closely with scientists
at UBC and at the B.C. Centre for Disease Control throughout
her investigations.
Within the next year, Duncan hopes her work will help
even more researchers gain valuable knowledge of Vancouver
Island’s C. gattii outbreak: the international journal Medical
Mycology has published one of her articles while several others
are in the review process at other medical and veterinary
publications.
For more information, visit the B.C. Centre for
Disease Control at www.bccdc.org (click on
Health Topics, A-Z).
Students Share
STUDIES at AAEP
While Sylvia Carley and Jodyne Green picked up knowledge at the
American Association of Equine Practitioners’ annual convention in December
2004, the student scientists also shared some new equine reproduction
findings with veterinarians from around the world.
Carley and Green, third-year veterinary students at WCVM, travelled
to the convention in Denver, Colorado, to present research papers based
on equine reproduction projects they helped to conduct as first-year
undergraduate students during the summer of 2003.
The students assisted equine reproduction specialist Dr. Claire Card with
several projects that focus on assisted reproductive technology in horses.
Card’s research team holds a multi-year, multi-project grant worth $277,911
from the Alberta Agricultural Research Institute. WCVM’s Equine Health
Research Fund has also supported several aspects of Card’s reproductive
research.
Nearly 6,300 veterinary professionals, exhibitors and guests attended the
AAEP’s 2004 convention that included close to 100 scientific presentations.
“The AAEP accepted both papers for publication in the AAEP’s convention
proceedings and for presentation at the December meeting,” explains Card.
“We were told that many papers were entered in this competition since this
was AAEP’s 50th anniversary convention, so we’re really very proud of Sylvia
and Jody for going this far.”
Frozen semen not inflammation source
Frozen semen has gained a reputation in the horse breeding industry
for causing acute post-breeding uterine inflammation in mares, and as a
result, lower pregnancy rates. But based on their research, Carley and Card
Continued on page 15
Above, from left to right: Sylvia Carley with Dr. Claire Card and Jodyne Green. Carley and Green
worked with the equine reproduction specialist on several studies at WCVM’s Goodale Research
Farm during the summer of 2003.
Western College of Veterinary Medicine 7
The Future is
WIDE OPEN
in Equine Dentistry
Imagine a visit to your dentist without the usual request
of “Open wide.” Sounds strange, but it’s nothing new in
the horse industry. Veterinarians have been examining and
treating horses’ teeth through the partially-open mouths of their
reluctant patients for centuries. But times are changing. The wideopen mouth of a horse is now one of the most visible signs of equine
dentistry’s evolution.
Since the introduction of safer sedatives and fast-acting general
anesthesia drugs in the past two decades, a growing number of veterinarians
are opting to use traditional tools like the full mouth speculum to identify and
treat dental pathologies.
“The full mouth speculum gives you a complete view of the horse’s
mouth so you can pick up on any dental problems, and you can show the
horse’s owner exactly what you’re seeing,” explains Dr. James Carmalt, a
surgical resident at the Western College of Veterinary Medicine (WCVM).
Despite the tool’s benefits, some experienced veterinarians prefer to
work without it. While that won’t make a difference in most cases, Carmalt
says it means clinicians may overlook dental pathologies that they can’t feel
or see (or a combination of the two) in their patients’ mouths.
One example is the diastema (an abnormal gap between two cheek
teeth in the same arcade). While people have known about this painful oral
condition for more than 160 years, no one (other than a German veterinary
dentist in the 1940s) has treated the problem.
“Diastemata (plural of diastema) are extremely difficult to diagnose
and treat without a complete oral examination. Horses often suffered and
wasted away without anyone realizing the problem,” explains Carmalt. “The
only way you can identify diastemata is with a full mouth speculum because
you need to feel them and see them. They’re fairly rare, but at the same
time, better drugs and equipment are allowing veterinarians to identify this
problem and do something about it.”
The full mouth speculum is also helping veterinarians put new equine
dentistry knowledge to work in the field. In the past 15 years, scientists
like Drs. Paddy Dixon and Ian Dacre of the University of Edinburgh have
conducted fundamental research that has finally given practitioners an
advanced picture of the horse’s dental micro-anatomy, how equine teeth
erupt, the mouth’s blood supply and of common dental pathologies.
“Scientists have produced more research articles and case reports about
equine dentistry in the last two decades than what has been written in the
last two centuries,” says Carmalt.
Above: A full mouth speculum gives a clear view inside a horse’s mouth. Right:
Surgical resident Dr. James Carmalt uses a motorized dental instrument to float a
horse’s teeth.
8
Horse Health Lines • Spring 2005
ADVANCED INSIGHT, ARCHAIC PRACTICES
On the surface, it looks like today’s veterinarians have all they need:
a primary knowledge base of equine dentistry, plus access to safer and more
effective anesthesia drugs. They also have the option of using motorized
dental instruments — tools that have had a significant impact on the way
veterinarians perform equine dentistry.
“We can now float a horse’s teeth significantly faster than the 10 to 15
minutes it takes to do it manually,” says Carmalt. The machines are also very
consistent: if veterinarians are floating the teeth of multiple horses at one
farm, the quality of each procedure isn’t affected by operator fatigue.
But when it comes down to putting practical dentistry into action,
Carmalt points out that not much has changed: the profession still relies on
many inefficient practices and anecdotal evidence.
For example, many veterinarians still “punch out” horses’ teeth rather
than pulling them out through the mouth. Although the latter method was
the first to be put in practice, veterinarians began punching out horses’ teeth
to save time and effort. Now, the profession is gaining a renewed appreciation
for the original extraction technique. “It takes more time, skill and patience
to pull a horse’s tooth through the mouth, but we can avoid problems
associated with punching out teeth such as leaving tooth fragments
behind,” Carmalt explains.
Research is in high demand, but
“Scientists
meagre funding and a lack of controlled
situations have deterred many
have produced
scientists from conducting clinical
more research
trials to study practical, dental issues
and to test accepted practices.
articles and case
One of the few exceptions was
reports about equine
a western Canadian research team
including Carmalt and Dr. Nadia
dentistry in the last two
Cymbaluk, director of veterinary
decades than what’s
research/field operations for Wyeth
Organics. In 2001, the team worked been written in the last
with 56 equine ranching horses to
two centuries.”
investigate the relationship between
“These are the only three clinical trials of
teeth floating published in equine dentistry,
and that’s since the Chinese started aging
horses in 630 B.C., so we truly are
on the cutting edge.”
feed digestibility and teeth floating. Contrary to conventional thought,
the researchers found that floating makes no difference to feed digestibility
— similar findings to two previous studies that were conducted in the U.S.
and in Italy with smaller groups of horses.
“These are the only three clinical trials of teeth floating published in
equine dentistry, and that’s since the Chinese started aging horses in 630
B.C., so we truly are on the cutting edge,” says Carmalt.
NEW AGE FOR AGE-OLD AGING SYSTEM?
While researchers now have a better understanding of teeth floating’s
true impact on feed digestibility, veterinarians still can’t definitively say
whether dental care is integral to a horse’s performance — a question that
horse people often ask.
“The owners want us to float their horses’ teeth, check their mouths
and make sure these animals have no dental problems before they deal with
their behaviour problems,” says Carmalt, who regularly examines the teeth
of young performance horses that have behaved badly during training. “It
makes sense that bad teeth would limit performance, and there’s significant
anecdotal evidence to say that is the case. But so far, there’s no scientific
evidence.”
Estimating horses’ ages is another area of interest for people involved
in equine sports. For centuries, horse people have gauged a horse’s age by
looking at the chewing surface of its lower incisors. This method is generally
accurate until a horse is five years old, but after that, accuracy diminishes as
the animal ages.
Since many equine sports involve older, experienced performance
horses, Carmalt believes there’s a need for a more accurate aging system
— especially when veterinarians must estimate horses’ ages for prepurchase
examinations.
To achieve a higher level of accuracy, Carmalt is developing a new
system where veterinarians look at the specific length of the enamel ridges
on a horse’s cheek teeth. “The challenge is we need to copy that ridge from
the tooth on to another medium — tracing paper, dental amalgum or a photo
— where we can physically measure the length of the ridge and compare it to
our mathematical models.”
When can horse owners expect to see the new aging system in place?
Not for awhile, says Carmalt, who must test the system’s accuracy on a large
number of live horses with known ages before it’s considered a viable option.
More work also needs to be done to make the aging system more practical.
But if it proves to be an accurate approach to estimating horses’
ages, this will be one more step in the evolution of equine dentistry — a
centuries-long process that is finally gaining momentum around the world.
The specialized area is also gaining a larger following of veterinarians who are
eager to contribute to its progress whether it’s in the research laboratory, out
in the field, or in the classroom.
At WCVM, Carmalt is one of several veterinarians who organizes
an annual morning of voluntary lectures on equine dentistry for third-year
veterinary students. After lunch, students try their hands at manually floating
the teeth of the College’s palpation mares.
“They have to know what it feels like to manually float teeth and to
have respect for the soft tissues in a horse’s mouth. The other reason is that
the majority of veterinary clinics out there don’t use motorized dental tools
so they need to be competent at doing the job manually,” explains Carmalt.
He adds that students gain more experience in diagnosing and treating dental
pathologies during clinical rotations in their final year.
Because equine dentistry is changing so rapidly, undergraduate students
aren’t the only ones keen on taking a closer, more informed look inside the
horse’s mouth. A case in point is Carmalt who learned how to perform root
canals in horses during a recent endodontic course.
“Root canals have been out there for four or five years. However, the
treatment of incisor and canine teeth is significantly more successful than the
treatment of cheek teeth due to their complex anatomy,” explains Carmalt.
“It’s now a service we can offer to specific cases where it’s crucial to the horse’s
performance and a practice we can introduce to our students.”
What’s amazing is that scientists didn’t completely understand basic
equine dental anatomy 20 years ago, and now, high-tech root canals for
horses are a reality. Equine dentistry’s future truly is wide open.
“Everybody is learning new things: we’re putting some of the old myths
to rest and at the same time, we’re generating more questions that need to be
tested,” says Carmalt. “If anyone is interested in learning more about equine
dentistry, there’s no excuse anymore — it’s all there.”
Want to read “Feed + Floating = Healthy Horse?” and
other dentistry-related articles? Visit www.ehrf.usask.
ca and click on to Horse Health Lines (Fall 2002) in PDF
format.
Western College of Veterinary Medicine 9
Scratches,
&Moose Ticks
RINGWORM
Western Canada’s most common
(and not so common) skin conditions.
D
r. Sue Ashburner still shudders when she describes the sight of one of
her equine patients covered with thousands of bloodsucking ticks last
winter. “We occasionally see wood ticks on horses during May and
June, but I didn’t know what kind of ticks would be on horses in February,”
admits Ashburner, a veterinary clinician at WCVM’s Large Animal Clinic in
Saskatoon, Sask.
Dr. Lydden Polley, a parasitologist at the College, soon solved the
mystery: he identified the parasites as Dermacentor albipictus (Acari: Ixodidae),
more commonly known as moose ticks.
“It was the first time I ever saw a horse in this area covered in moose
ticks,” says Ashburner. “That’s what I like about working on dermatology
cases. There are always new things, and those cases challenge you to find out
what you’re dealing with. Sometimes we never know the cause, but we usually
know how to treat what we see.”
At least once a week, Ashburner gets a chance to use her dermatological
know-how on equine patients living around Saskatoon — an area that’s
populated with horses of all breeds and disciplines. The clinic’s number of
dermatology cases usually rises in the spring after horses shed their coats and
owners suddenly notice lumps, bumps, growths or parasites that have shown
up during the winter.
Thanks to advances in diagnosing and treating equine skin conditions,
veterinarians can offer clients more effective therapies and more understanding
of what causes skin problems to develop. Most clients call for advice or to
arrange for a veterinary visit, but some still insist on using their own home
remedies that often makes Ashburner’s job tougher. “After they’ve scraped it,
treated it or used ointments that burn the skin, it doesn’t look anything like it
originally did. These remedies usually just make things worse.”
While Ashburner isn’t expecting another moose tick infestation
case soon, here are some common skin conditions that she and veterinary
pathologist Dr. Ted Clark regularly see out in the field and in the pathology
laboratory. Their comments accompany some additional information gleaned
from the text, Equine Dermatology, co-authored by Drs. Danny Scott and
William Miller Jr.
• Dermatophytosis or ringworm is a fungal infection that’s transmitted
by contact with infected hair, bedding, tack and grooming equipment.
Ashburner often diagnoses multiple cases of ringworm in young horses living
in close quarters throughout the winter months: the infection often goes
unnoticed until horses shed their winter coats.
The most consistent clinical sign is one or many circular patches of
alopecia (hair loss) with variable scaling and crusting. But horses may also
10
Horse Health Lines • Spring 2005
develop the classic ring lesion with a healed centre and fine follicular papules
and crusts on the ring’s edges. Lesions are usually multiple, and they’re most
commonly found on the face, neck, the sides and girth. The lesions usually go
away within three months, but veterinarians often use topical and systemic
treatments to help their patients’ response to the infection, to reduce the
spread of the fungus and to speed up the healing process.
• Sarcoids are the most common skin tumour of horses around the world.
Veterinary researchers believe the cause of sarcoids is viral, and research has
shown that bovine papillomaviruses (BVP) are commonly involved in sarcoid
development. Lesions frequently show up in areas of a horse’s body after a
wound or trauma, or they may also spread to other areas of the same horse or
to other horses through biting, rubbing, tack, equipment and insects. Sarcoids
occur anywhere on a horse’s body, but most lesions are found on the head,
neck and ventral body surface. The lesions’ appearance can be verrucous
(wart-like), fibroblastic (proud flesh-like), mixed verrucous and fibroblastic,
and occult (flat).
Sarcoids do not metastasize, and some tumours may disappear after
several years. Depending on available resources, veterinarians can choose
from surgical excision, cryosurgery, radio-frequency hyperthermia, laser
therapy, radiotherapy, chemotherapy, immunotherapy or combinations of
treatments.
• Papillomas present in two different forms: as warts (viral papillomatosis)
or as aural plaque (ear papillomas). Viral papillomas spread through direct
contact or indirectly through contact with contaminated equipment or
housing. Young horses often develop clusters of warts, usually on their muzzles
or lips. “They bother the owner much more than horses,” says Ashburner. “If
left alone, they tend to go away and you can’t rush them. People always buy
potions and lotions, but they usually make no difference.”
Aural plaques — white-greyish crusts commonly found in horses’ inner
ears — don’t respond very well to topical treatments, and they rarely go away.
Fortunately, these lesions are only a cosmetic problem.
• Eosinophilic granuloma or nodular necrobiosis is an equine dermatosis
most commonly seen in the spring and summer. These nodules are round,
elevated, and occur as single or multiple
lesions on the back, withers and neck.
The lesions aren’t painful or itchy, and
the overlying skin and hair coat are
normal. Veterinarians can surgically
remove one or several lesions, or
treat multiple lesions with systemic
glucocorticoids over several weeks. Some
lesions undergo spontaneous remission in
three to six months, while older or larger
lesions must be surgically removed.
cream — to fight the mixed infection,”
explains Ashburner.
Clark adds that it’s important for
veterinarians to be aware that scratches
isn’t “one specific disease with one
specific cause.” If certain horses or horse
herds continue to be plagued by this
type of dermatitis, practitioners need to
look at the animals’ environment, their
habits and what they’re used for to learn
more about probable causes.
• Allergic reactions show up as
• Rain scald (dermatophilosis)
anything from bumps and wheals in
is a bacterial skin infection that causes
all shapes and patterns to angioedema
superficial, pustular and crusting
(swelling) involving the muzzle, eyelids,
dermatitis in horses. These lesions
under the belly, legs or the entire body.
are most commonly found on horses’
These reactions result from insect bites,
rumps, saddle area, face and neck — or
plants, drugs or vaccines, a change in
on pasterns, coronets and heels (in the
feed, bedding or the horse’s environment.
form of scratches).
Gathering a thorough medical history
The two most important factors
“That’s what I like about working on
is how veterinarians usually track down the
that lead to rain scald are skin damage
dermatology cases. There are always and moisture. The condition is often
source, says Ashburner. “It could be caused
by a minor environmental change, a sudden new things, and those cases challenge diagnosed in horses after intense rain, and
hatch of bugs in the area. It really pays off to you to find out what you’re dealing with. when temperatures and humidity are high.
ask a lot of questions.”
Veterinarians on the Prairies don’t often see
Sometimes we never know the cause, rain rot, but it’s a common problem in B.C.
Ashburner and her colleagues
but we usually know how to
usually try to eliminate the source of
While most cases of rain rot go away
hypersensitivity or generally treat the horse
within
a month, the best treatments include
treat what we see.”
to try and decrease its immune response.
keeping the animal dry, removing crusts, and
“One treatment that has worked quite well is to feed the horse raw linseed oil:
using topical treatments and using systemic therapy if the infection is chronic
its Omega 3 fatty acids help to decrease the animal’s hypersensitive response
or severe.
in the skin. That seems to calm things down and it helps to make the other
• Insect hypersensitivity: Western Canadian horse owners and
treatments work better.”
veterinarians deal with fewer parasitic problems than in other parts of the
• Scratches or pastern dermatitis most commonly affects one or both
world because of the region’s cooler climate, but insect hypersensitivity is still
hind limbs with varying levels of pain and itchiness. The condition initially
a common problem in the spring and summer months. Controlling insects
shows up as erythema (dew poisoning), swelling and scaling on the pastern,
and using anti-itching agents can help to manage insect hypersensitivity. The
then progresses to discharge, matting of hair and crusting.
use of ivermectin, moxidectin and other dewormers has also helped to reduce
Veterinarians usually diagnose this problem when there’s abrasive mud
the occurrence of conditions like sweet itch, says Ashburner.
in corrals, or when ice crystals are mixed in the snow and dirt. “We think
- Sweet itch or Summer Seasonal Recurrent Dermatitis (SSRD): The most
the moisture content has something to do with it: something seems to set
important cause of equine insect hypersensitivity is Culicoides gnats (sandflies,
up the right environmental conditions to induce scratches, particularly in
no-see-ums, biting midges). Affected horses develop itchy, crusted papules on
the spring,” says Ashburner, adding that the condition usually shows up on a
the top of their tails, along their mane, neck, withers, hips, ears and forehead.
white leg.
The disease’s itchy nature causes horses to scratch and chew at themselves,
“It responds very well if treated early, but it’s often missed by the owners
or they may rub against stalls or fences. That can lead to hair loss, ulcer
until the horse’s pastern is very sore or very swollen. And the longer they
development and damage to the animals’ manes and tails.
have it, the harder it is to treat.” Severe cases of scratches can also lead to
- Mange is caused by mite infestations in horses’ coats. Owners and
a longstanding, immune-mediated infection called vasculitis that can take
veterinarians usually see these infestations during the late winter and early
months to cure.
spring, and contributing factors include crowding, prolonged stabling, and
If diagnosed early, the ideal treatment is to clean the area very well with
poor nutrition.
mild soap (no abrasive cleaners) then remove as much of the scabby debris
- Lice infestations are commonly found in horses during the winter when
as possible. Clipping the hair can help to remove the scabs. “We keep the
the animals’ coats are longer and they may be in close contact with their herd
area dry and use a topical cream — a combination of antibiotic and steroid
mates. Biting lice are usually found on the horses’ dorsolateral trunk, while
sucking lice prefer the animals’ mane, tail and fetlocks. Clinical signs include
Left: A case of pastern dermatitis (scratches). Top: Young horses often develop
scaling, a dishevelled coat, hair loss and mild to moderate itchiness.
clusters of warts, usually on their muzzles or lips. Centre: Rain scald-associated
lesions are most commonly found on horses’ rumps, saddle area, face and neck.
Western College of Veterinary Medicine 11
Skin-deep ATTRACTION
Dr. Danny Scott had only scraped the
surface of his lecture topic when he
stopped to make something very clear
to his listeners. “There isn’t anything
I’d rather do than see, hear and
talk about skin disease — because
nothing rocks more than skin disease,”
declared the Cornell University veterinary
professor with a wide grin.
Scott’s infectious enthusiasm for his profession drew
laughs, plus plenty of admiration from his appreciative
audience. Few people in the world know as much about
veterinary dermatology as Scott does, explaining why his
name is associated with dermatological “bibles” such as
Small Animal Dermatology, Large Animal Dermatology, and
most recently, Equine Dermatology.
In January 2004, Scott spent a week in Saskatoon as one
of WCVM’s D.L.T. Smith guest lecturers. “In the last 25 years,
Danny Scott has taken veterinary dermatology from ‘orphaned
disdain’ to an organized specialty,” said Dr. Sherry Myers as
she introduced the skin specialist, researcher and diplomate
of the American College of Veterinary Dermatology to his
audience.
Back in Ithaca, New York, Scott uses his three decades of
experience to diagnose and treat challenging skin diseases in
dogs, cats and horses on a daily basis at Cornell University’s
Hospital for Animals. His specialized training in dermal
pathology also enables him to gain a microscopic view of his
patients’ skin problems.
And just why is he so passionate about studying skin?
“Because it’s all just hanging out there. The gross pathology
is right there before your eyes: you can see it, you can smell
it, you can feel it, you can taste it. It’s all right there for the
taking,” Scott explained to Horse Health Lines. “The owners
see their pets’ skin, too — so it’s obvious to them if you’re
making a difference or not. It’s quite a humbling specialty
because you can’t hide anything from anyone.”
12
Horse Health Lines • Spring 2005
Q
How did you become interested in veterinary dermatology?
When I went through veterinary school at the University of California
Davis, my favorite veterinary professor was Dr. Tony Stannard. Then, when
I came out to Cornell to do my internship in 1971, I met Dr. Bob Kirk who
continues to be my Dad-away-from-home and the best veterinarian, the
best people person and the nicest guy I ever met. Those two people really
intrigued me and both happened to be dermatologists.
The other thing that really interested me was that veterinary
dermatology was such a black hole. So many conditions had no names,
so many therapies were totally anecdotal and not based on any disease
understanding. For example, when I graduated, there was about 50 known
skin diseases. Now, there are over 500. There has been an explosion of
information, and it’s been exciting to be part of that. I liked the challenge of
the unknown: trying to push the frontier and remove some of the mysticisms
surrounding veterinary dermatology.
Q
What helped you understand veterinary dermatology?
About nine years after I came to Cornell, I took my first sabbatical
at the University of Minnesota’s medical school in dermatology. I went to
specifically study skin pathology because at that time, no one in veterinary
medicine had formal training as a dermal pathologist. Like many other
people, I had taught myself dermal pathology, but I really wanted to see
what could happen at a higher level.
I spent a year looking at human skin biopsies through a microscope,
and it was probably the single most explosive, professional growth year for
me. I saw things and heard about things that never occurred to me. I came
back tremendously enriched, and that was when I started developing the
pattern analysis approach to veterinary dermal pathology which is now
an institution. That all stems from my experience in human dermatology.
It broadened my understanding, my appreciation for dermatology. It also
increased the number of diagnoses I could make — because it’s pretty
difficult to diagnose something if you don’t even know it exists.
Above, left to right: A close up look at an equine sarcoid; hyperextensible skin is a
clinical sign of hyperelastosis cutis; a horse that has lost large amounts of telogen
(resting) hairs; draining an atheroma — a cyst of the nasal diverticulum or false nostril. Facing page, top: Serum scalding after an injection. Centre: Skin sores developed
all over this horse’s body when its owner forgot to rinse off shampoo after a bath.
Q
What makes dermatology so tricky?
Part of the challenge is that as an organ and
as a tissue, skin has a limited number of reaction
patterns. In other words, skin has a limited
number of ways that it can react to billions of
stimuli. In the eyes of most veterinarians (other
than dermatologists), many skin diseases tend to
look the same, so unless you spend a long time
picking up on the nuances, these conditions can
lead you down a merry path over and over again.
As a specialist, it’s not unusual for me to see a
patient who has been examined by four to six
veterinarians, who has had a double-digit number
of diagnoses made by one or more people and
who has been through all kinds of unsuccessful
therapies.
It was Goethe that said, “What is the
most difficult of all? That which seems to you
the easiest, to see with one’s eyes what is lying
before them.” That’s particularly apropos for
dermatology.
Equine dermatology doesn’t have any corner
on the anecdote market, but it’s an area that
has certainly been rife with them over the years.
Frankly, there aren’t enough days or cases to
address all of them in my lifetime. But every once
in awhile, I’m confronted with one that seems
to work into my plan for the next year, so we’ll
set up some kind of pathological or therapeutic
routine to address that particular anecdote. It’s
fun to show whether these anecdotes are the truth
or not, and I must confess that it gives me a cheap
thrill to blow one of those things out of the water!
Q
What does it take to be a good
veterinary dermatologist?
You have to be a person whose selfimage and daily goals aren’t based on instant
gratification because those little moments don’t
come along very often in dermatology. If you’re
an orthopedic surgeon, you fix the problem and
then you may never see that particular patient
again. But many of these chronic skin conditions
require a lot of client education, a lot of phone
time, and a lot of temporary frustrations as things
spiral out of control in a particular month. The
gratification may be borne out over seven to eight
years when one of your patients finally dies of a
natural cause and the owners tell you how much
they appreciated the time you took on the phone
or the time you spent tweaking the treatments.
Q
What can veterinarians do to ensure
more accurate diagnoses?
If there’s one place where practitioners
come up short, it’s that they just don’t
accumulate their patients’ histories. Everything
is an important piece of the puzzle. If you have a
really good history, that history could eliminate
nine of the 10 possible diseases and give you the
most likely diagnosis.
Of course, I do understand that time and
money are issues when you’re in practice: it can
take at least a half-hour and even longer to get
a good history on a chronic case. Practitioners
often don’t have time to go back to the beginning, come up to the present and take a few side
trails. On the other hand, that extra time could
save them a lot of frustration.
Q
What’s your clinical work like?
I spend a lot of time teaching students and diagnosing skin diseases,
but another part of my job is to give my clients long-term prognoses.
Because of the types of diseases that I deal with, I have to let them know
that we’re not going to cure this condition by November 2005 and that we’ll
become very good phone pals through the ups and downs of these diseases.
Many skin conditions aren’t curable: they require lifelong management so
we may need to tweak our therapies from month to month or year to year
based on factors such as higher levels of pollen or mould spores in the air.
Q
How do you choose research topics?
A lot of what I publish is about microscopic nuances that I notice as
I look at interesting patients and various things. I start formulating these
little, anecdotal “gut feelings,” then I convince some resident to work on my
idea, confirm my gut feeling or blow it away, and we eventually get the work
published and push the frontier a tad.
For more equine dermatology stories,
visit www.ehrf.usask.ca and click on
to Horse Health Lines (Fall 2004) and
related articles.
THE
GALLOPING GAZETTE
WCVM Presents
In January, Dr. James Carmalt gave a talk entitled “Does dental
care affect digestion?” at the 2005 Alberta Horse Breeders and Owners
Conference in Red Deer, Alta. Two months later, Carmalt was also one of
several WCVM representatives who took part in the Saskatchewan Horse
Federation’s annual conference where the organization celebrated its 30th
anniversary.
During the conference’s horse health and welfare section, Carmalt
gave a presentation called “Colic: is it as bad as it seems?” while Dr. Trish
Dowling gave the veterinary point of view in a panel discussion called
“The good moving horse.” Other featured speakers included veterinary
pharmacologist Dr. Chris Clark and internal medicine specialist Dr.
Katharina Lohmann.
Continued on back cover
Western College of Veterinary Medicine 13
M
ore than seven
tributes: lifetime memberships
decades ago, an
in the National Cutting Horse
Edmonton, Alta.,
Association and the American
teenager wrote an essay in
Quarter Horse Association,
high school about his ambition
and the title of honourary viceto own a farm and to build a
president with AQHA.
life for himself that revolved
George’s most prized horse
around horses, cattle and the
was a son of King P-234 called
country. It took a few more
Fred B. Clymer — a talented
years for that young man to
cutting horse that earned
fulfil his dreams, but the words
sixth place in the NCHA’s
written by George Golden’s
1966 World Championships.
teenaged self essentially charted
The stallion also received the
the course of his life.
NCHA Bronze Award and was
“The farm was always
classed as one of the AQHA
really special to George. As
Superior Cutting Horses
a boy, he used to spend all
with an impressive record of
of his summers at his uncles’
four halter points and 101
farms near Lavoy (Alta.) and
performance points.
that’s when he decided to be
“George mainly competed
a farmer,” explains Eleanor
in cutting horse competitions,
Golden. Eleanor first met her
and all of the girls competed
future husband while she was
in horse shows when they
visiting the sisters of Stuart
were younger,” recalls Eleanor,
Hart, and George was working
who prepared meals and clean
out with the famous wrestler.
outfits for her husband and
The couple eventually
daughters during competitions.
married in 1941 and lived
George even took a couple of
in Vancouver, B.C., until
daughters on longer treks to
George joined the Canadian
compete in Ontario and the
Navy for a year and a
U.S. “He really enjoyed those
half. After returning from
summers on the road. We won
overseas, George established a
so many trophies, we didn’t
construction firm called G.W.
know where to put them all.”
Golden Construction Limited
It was during these busy
in Edmonton — the first of
years when George became
a series of successful business
acquainted with the Western
ventures in construction, saw
College of Veterinary Medicine
milling, lumber production and
and its future plans for equine
ranching that he developed
health research and advanced
during his lifetime.
veterinary training. After
The Western College of Veterinary
But the business closest to
chairing the College’s equine
Medicine’s Equine Health Research Fund
his heart was the family’s ranch
research advisory committee
located 24 kilometres east of
pays tribute to one of its founders — George from 1971 to 1974, George was
Sherwood Park, Alta. After
of four Alberta horsemen
Golden. The Alberta horseman passed away one
buying the property in the
who contributed $15,000 each
on October 16, 2004, at the age of 88.
late 1940s, George built a new
to establish WCVM’s Equine
ranch home for Eleanor and
Health Research Fund in 1977.
their four daughters — Patricia, Doreen, Nadine and Elaine — in 1954.
George continued to serve as a member of the Fund’s advisory board until
While George took pride in raising beef cattle, it was his horses that
1983.
earned him special recognition. He was one of the first to breed and show
“We were all just interested in the horse business and in the health
Quarter horses in Western Canada, and from the 1950s to 1980s, the
of horses,” explained George during an interview for the Fund’s 25th
Golden name became synonymous with champions in Canada’s Quarter
anniversary in 2002. “We were just trying to help.”
horse industry and on the Western horse show circuit. George’s longtime
Above: George Golden astride his mare, Pepsi Clymer, after winning first in a
involvement in the Quarter horse industry also earned him several major
GEORGE GOLDEN, 1916-2004
GOLDEN
YEARS
Western Pleasure class.
14
Horse Health Lines • Fall 2004
“He was just a very down-to-earth,
friendly person who was interested in
veterinary medicine, in horses and in
bettering their lives.”
But George provided much more than financial support to the
fledgling organization. “The Fund’s future relied on whether Western
Canada’s horse community would rally around this idea and support it,”
points out Dr. Ole Nielsen, WCVM’s dean from 1974 to 1982. Nielsen
also initiated the development of a regional equine health research fund.
“Prominent horse people like George who volunteered their time, leadership
skills, and their influence were crucial to the Fund’s success.”
Besides supporting EHRF, George often trailered his Quarter horses
to WCVM’s Large Animal Clinic for specialized care. One faculty member
who often worked on the rancher’s mounts was Dr. Peter Fretz. In particular,
the surgical specialist recalls meeting George soon after returning from a
1980-81 sabbatical leave at Colorado State University with Dr. Wayne
McIlwraith — a world-renowned specialist in equine arthroscopy.
“I took a large fragment of bone out of the hock of one of George’s
horses, and afterwards, he asked me how it went. I mentioned to George
that we could have done the same surgery with an arthroscope — except we
didn’t have the equipment at WCVM.”
Shortly after, Fretz was amazed to hear that George had sent a $25,000
cheque so WCVM could purchase its own arthroscope and begin offering
horse owners the minimally-invasive technology as an option to traditional
surgery. Having the equipment at the College also enabled Dr. Mark Hurtig
— the Equine Health Research Fellow from 1982 to 1984 — to develop
arthroscopic techniques during his surgical residency.
Another of George’s unexpected gifts to WCVM was an exercise
treadmill — worth more than $7,000 — that was used to walk equine
clinical patients. “I’m sure he just looked around and saw that we didn’t
have any proper exercise equipment, talked to a few people, then decided to
purchase it. We certainly didn’t ask him for it, but that was just the way he
liked to do things,” says Nielsen.
“When the Fund’s travelling equine health seminars came to Alberta,
George always came, he was always one of the first to write a cheque, and
he always set the standard,” adds Fretz. “He was just a very down-to-earth,
friendly person who was interested in veterinary medicine, in horses and in
bettering their lives.”
Those recollections make Eleanor smile in agreement. “There
was nothing George liked better than talking to people. He was always
interested in what people were doing and planning — and that was usually
what convinced him to help out.” Besides WCVM, many people and
organizations — including an Edmonton hospital and several local churches
— benefited from George’s generous nature. “He did a lot of good in his day,
and he was pretty thoughtful in his ways,” says Eleanor, his wife of 63 years.
Five years ago, George and Eleanor moved into a Sherwood Park
condominium where they enjoyed countless visits with their daughters and
their expanding families of 12 grandchildren and six great-grandchildren.
And even when illness prevented George from visiting his beloved ranch,
his keen mind never stopped running the place — never stopped picturing
the cattle, the horses, the crops, the hay land, everything.
“All he ever wanted was to own a farm, and he got it,” says Eleanor.
Indeed, George Golden got it.
AAEP cont’d from page 7
say frozen semen doesn’t deserve the bad rap: their 2003 study
demonstrated that breeding with one full dose or two half doses of
frozen semen did not significantly increase the amount of bacteria,
endometrial debris and the percentage of neutrophils measured in
uterine lavage samples.
Those findings come from a WCVM project that involved 37
young, fertile mares separated into three groups. While control
mares received no breeding treatment, Carley and Card bred
the second group of mares with a single dose of frozen semen
on the day of ovulation. The research team bred the third group
with two half-doses of frozen semen: one breeding at ovulation
and another breeding 24 hours later. The scientists collected low
volume uterine lavage samples 24 to 96 hours post-breeding
during a total of 40 cycles, and relied on the expertise of veterinary
microbiologist Dr. Manuel Chirino-Trejo to analyse slides for
bacteria.
“There was no significant difference between the control
group and the single breeding. The neutrophil counts in the singlebred mares were no higher than four per cent — what you would
expect in a mare that had just been bred — and any inflammation
that may have been present had resolved itself very quickly after
the single breeding,” says Carley.
She adds that while the second group of horses did have
higher amounts of bacteria, endometrial debris and neutrophil
percentages than the single-breeding mares, the differences
weren’t significant.
The same study also helped researchers set a baseline for
the normal range of endometrial cytologic parameters — valuable
information that can help practitioners evaluate mares postbreeding. Based on their findings, Carley and Card say that an
average neutrophil count of five per cent following breeding is
normal for mares selected for good breeding potential.
“Any time a veterinarian evaluates a mare 24 hours after
being bred with frozen semen and sees anything more than an
average of five per cent of neutrophils on the slide, it indicates that
there’s a problem,” says Card. “That’s important because until this
point, nobody knew what the magic number was.”
Fits to a T
Green’s paper described the effects of using inexpensive
controlled intravaginal drug release (CIDR) to synchronize estrus
in large herds of horses. The key part of this method is a T-shaped
plastic device that releases progesterone intravaginally for up to
14 days in mares.
While owners have been concerned about whether the
CIDR device affects mares’ fertility, Green found no difference in
pregnancy rates among horses that used the device and those
that didn’t. However, minor side effects (small amounts of vaginal
discharge and urine scald) could potentially cause complications
in mares that have past breeding problems. As a result, Green and
Card advise that the CIDR devices are best suited for use in mares
without a history of breeding problems (see the Spring 2004 issue
of Horse Health Lines at www.ehrf.usask.ca to read more about
CIDR research).
Western College of Veterinary Medicine 15
THE
GALLOPING GAZETTE
(cont’d)
Veterinary Teamwork
In January 2005, Dr. James Carmalt leapt out of his hectic life as a surgical
resident at the Western College of Veterinary Medicine to jump into another
demanding job: Canada’s team veterinarian at the 2005 Fédération Equestre
Internationale (FEI) World Endurance Championships in Dubai, UAE.
Carmalt was certainly qualified for the role: he became an FEI-certified
endurance racing veterinary judge nearly two years ago and has served as
a foreign delegate at several U.S. endurance races. As well, Carmalt was
Canada West’s team veterinarian for the 2003 Pan American Endurance
Championships at Mount Adams, Washington, where the team won a
bronze medal.
“They’re two very different roles, and it’s nice to have experience on
both sides of the fence. I know what the judges are looking for when I bring
my team’s horses forward at these world events, and if I wouldn’t pass a horse,
chances are the judges will share the same opinion,” says Carmalt.
At 6 a.m. on January 27, 178 horses and their riders from 41 countries
started in the 160-kilometre (100-mile) endurance race across the Arabian
desert. Just over seven hours later, the race’s leaders crossed the finish line to
win the largest FEI event ever held.
Altogether, 61 horses and riders completed the race including three
of the five Canadian competitors. Those results earned Team Canada a
fourth place in the world championship’s team event — an incredible
accomplishment, says Carmalt. “It was a flat race, and the Arabs run flat
horses very well. In contrast, we tend to have general-purpose and mountaintype horses, so our team came from competing at Mount Adams to the
extreme opposite in terrain at Dubai and won fourth overall. I’m extremely
proud of them.”
Other than the flat terrain, Carmalt says the desert climate didn’t cause
any difficulties for the Canadians. “Beforehand, we worked on some of the
horses’ little niggling problems, but once race day came, we just had to accept
that what will happen will happen — and you just deal with it. That’s no
different whether you’re at the World Championships or at a local race.”
During the race, Carmalt gained valuable experience in identifying
lamenesses in endurance horses — including subtle injuries that only became
evident after a certain number of miles. “There were nearly 180 horses in the
race and each horse ‘trotted out’ (part of the veterinary examination process)
about five times throughout the entire competition. That’s nearly 1,000 trots
within a 13-hour period, so it was an incredible chance to improve your
ability to detect signs of lameness.”
It was also the ideal opportunity to watch how other teams managed
their horses during the race’s mandatory veterinary checks. “It was very
interesting to see how the crew dynamics worked in other teams like the
HORSE HEALTH LINES
Horse Health Lines is a publication produced by the Western
College of Veterinary Medicine’s Equine Health Research
Fund. Articles from Horse Health Lines reprinted in other
publications should acknowledge the source. Please send
questions or comments to:
Dr. Hugh Townsend, Editor, Horse Health Lines
WCVM, University of Saskatchewan
52 Campus Drive, Saskatoon, SK S7N 5B4
Tele.: 306-966-7453 Fax: 306-966-7274
wcvm.research@usask.ca
UAE team that descended on one of
their horses like a Formula One pit
crew. Literally, within 30 seconds,
their horse was bare naked and
being cooled.”
But what Carmalt will never
forget was the unique opportunity to
see the world’s most elite endurance
horses perform at the sport’s highest
level. “For example, I remember
watching the French rider who was
five minutes behind the first group of horses just before the race’s final stage.
In that final loop, her horse galloped flat out, with no whipping or spurring.
Their average speed was 31 kilometres per hour — and this was after already
running 141 kilometres of the race. It was just incredible to see that calibre of
horse perform its best.”
WCVM Presents
In October 2004, Dr. Spencer Barber spoke about racetrack injuries at
the Canadian Racetrack Officials conference in Saskatoon, Sask. In January,
Barber travelled to Orlando, Florida, to give five presentations on different
aspects of wound healing at the North America Veterinary Conference.
Last fall, Horse-Canada published an article called “Proud Flesh:
When Granulation Goes Wild” that was based on writer Nicole Kitchener’s
interview with Barber. As well, one of Barber’s articles called “Managing
Fractures of the Facial Bones in Horses” will appear in the Spring 2005 issue
of the Veterinary Wound Management Society’s newsletter.
Above: The scene shortly before 178 horses and their riders begin the World Endurance Championship race at 6 a.m. on January 27. Right: Myna Cryderman and her
Arab mare, Night Skye, were the first members of Team Canada to finish with a
time of 11 hours, 10 minutes and 13 seconds. Canada’s Yvette Vinton and Daphne
Richard also finished the race — earning fourth place for Canada in the team event.
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