Tracy Walker, DVM
The Healthy Horse
Route 1 Box 115
Elkins, WV 26241
(304) 636-8363
Early Spring 2006
Vaccines – Part 1 The Basics
The time for Spring vaccinations is approaching. There are lots of vaccines available on the market from lots of different
companies. No single protocol is appropriate for every horse. Age, health status, pregnancy, risk of exposure to disease,
environment and use all play an important role in designing a vaccine protocol specific to your horse.
There are three basic types of vaccine: killed, modified live, and the newer DNA recombinant vaccines. Killed vaccines use
a dead disease agent. The advantage is that there is no risk of the animal contracting disease due to the vaccine. The
disadvantage is that it requires lots of adjuvant to stimulate the immune system in the animal. Adjuvant is a compound that is
in the vaccine mixture. Adjuvant is also what is associated with allergic reactions or localized swellings.
Modified live vaccines use a live disease agent that has been weakened or slightly altered. The advantage is that this
typically produces better overall immunity. It also has less adjuvant, thus less chance of allergic reactions and localized
swellings. The disadvantage is that some horses will develop a low grade sickness. This is usually not a problem but can
cause abortions in mares. An example of a modified live vaccine is the human flu vaccine. Many of you can appreciate the
“flu-like” symptoms you feel after getting vaccinated even though you don’t develop the full blown flu.
The DNA recombinant vaccines have only become available in the last few years for limited diseases. These vaccines do an
excellent job of stimulating the immune system with no risk of developing low-grade disease and use minimal adjuvant. The
only recombinant vaccine available for horses is the new West Nile vaccine produced by Merial.
How should we vaccinate foals and broodmares? Foals acquire their initial immunity from the mare’s colostrum. For this
reason, it is important to keep the mare well vaccinated and it is essential that the foal receive adequate colostrum within the
first few hours of birth. The immunity the foal receives at birth will last until 4 to 6 months of age and then progressively
decreases. In general, we begin vaccinating foals between 4 and 6 months of age in attempt to overlap the time that the
maternal immunity is decreasing. Age of initial vaccinations depend on risk of the foal and vaccination status of the mare.
Boosters are essential and should be given 8 weeks after the first vaccination. Some foals will require an additional booster.
Again, this depends on risk and history of the mare.
Why do we booster adult horses? The initial vaccine that a horse receives stimulates antibody production against the disease.
The booster vaccine is required to stimulate “memory” of these antibodies. Essentially, the booster transfers the antibody
response from short term to long term memory. Yearly boosters are recommended for most vaccines to maintain this
“memory”. Some vaccines stimulate excellent short term protection and antibody production but do not stimulate good
memory. The equine intranasal flu vaccine is a good example. This vaccine produces superior protection to the flu virus but
the immunity only lasts a few months.
In the next newsletter, we will address specific diseases and why we vaccinate against them.
Mark you Calendars!
May 6, 2006 10 AM
Camp Pioneer, Beverly
Area horse owners of all ages are encouraged to attend this seminar on
equine health and nutrition. For more information, please contact
Dr. Walker.
636-8363
Equine Emergency Review: Choke
Choke, or esophageal obstruction, is an emergency that you should learn to recognize. In people, we associate choke with a
blockage of the trachea. In horses, choke is associated with an obstruction in the esophagus, not the trachea. The
obstruction is usually at the bottom of the esophagus just before the entrance to the stomach.
A horse that is choking will act very depressed, usually holding the head at or below the withers. Saliva and mucous mixed
with food material will be draining out of one or both nostrils. Some horses will attempt to drink by dunking their nose, but
they will not actively swallow. Affected horses typically do not attempt to continue eating. Regardless, access to additional
food or hay should be immediately eliminated.
Choke can be caused by a variety of factors. Poor dental health is one of the most common causes. Abnormalities in the
dental arcade, such as a wave mouth or sharp points, prevent proper mastication of feed. Older horses are especially at risk
since the molars are very worn or missing. In addition, some feed types such as alfalfa cubes, bran, beet pulp are more likely
to cause an obstruction. These dry or highly compressed feeds soak up saliva and can expand too rapidly as they are being
swallowed. To prevent this rapid expansion, such feeds should be soaked with water prior to feeding.
Regardless of the cause, immediate treatment by your veterinarian is needed. Treated early, choke can be cured without
complication. However, if a choke is allowed to persist, permanent damage can occur to the lining of the esophagus.
Aspiration pneumonia can also occur from inhaling some of food/saliva mixture into the lungs. Both of these complications
are very serious and can lead to death. Treatment includes sedation to lower the head and relax the esophagus. A stomach
tube is then passed to help dislodge the obstruction and push it gently on to the stomach. Occasionally, water is flushed in to
loosen, break up and lubricate the obstruction. Antibiotics and additional medical therapy may be given depending on the
individual case need.
Recurrence of choke is most likely during the first 48 hours after an episode. During this time, the lining of the esophagus is
still irritated. Horses that have suffered from recurring choke may require special dietary management and vigilant dental
care.
Should this occur to your horse…….1) Call your vet. 2) Remove all feed & hay from the stall. 3) Try to keep his head
lowered. This reduces the chance of aspirating food material into the trachea. 4) Do not try to flush or force a water hose
into the mouth. This will only stress the horse and increase the chance of aspiration.
Check out the website at
Tracy Walker, DVM
Route 1 Box 115
Elkins, WV 26241
www.alleghenyequine.com.
2006 Area Equine Events
April
1
10 AM
2
10 AM
4-H & Open Schooling Show Hosted by The Pony Garage at Camp Pioneer,
Beverly. Contact Sonya Penson for more info and show bill @ 304-636-6711
Health Clinic hosted by Dr. Tracy Walker at Camp Pioneer, Beverly
Health exams, vaccinations and coggins.
RCRRC activity at Camp Pioneer
NWVQHA Show at Barbour Fair Grounds
NWVQHA Show at Barbour Fair Grounds
Parelli Level 1 & 2 Clinic @ Shalimar Farm, Cass
For more info call 304-653-8547
8/9
8/9
14, 15/16
29/30
May
6
9:00 AM
27
26, 27/28
Purina Nutrition Seminar at Camp Pioneer hosted by Dr. Tracy Walker .
RSVP appreciated for head count. 304-636-8363 or trwalker3@aol.com
RCRRC Benefit Ride at Ross Farm (new trail)
NWVQHA Show at Barbour Fair Grounds
June
17
10 AM
26-30
Tri-County/ RCRRC Merging Open Show at Camp Pioneer
Greenbrier River Trail Ride (all invited to attend all or part)
July
29/30
NWVQHA Show at Barbour Fair Grounds
August
13
12/13
26
RCRRC Benefit Ride in Huttonsville (new trail)
NWVQHA Show at Barbour Fair Ground
2nd Annual RCRRC Summer Celebration Horse Show Camp Pioneer
September
9/10
9/10
17
23/24
Mule Show in Flatwoods (trail ride on the 9th)
NWVQHA Show at Barbour Fair Ground
Dry Fork Ride (may be a 2-day event beginning on the 16th) new trail
NWVQHA Show at Barbour Fair Ground
For more information on Randolph County Regional Riding Club events,
Please contact Diane Ross @ 636-7486 or onthefarmat40@hotmail.com
Regular Meetings are held every 3rd Thursday.
Events are also posted at www.alleghenyequine.com
If your organization has any events that you would like to include on this calendar, please email Dr.
Walker at trwalker3@aol.com