May 2010
Veterinary Teaching Hospital
Infectious Disease Management Guidelines
Guidelines and Procedures
I. Recommendations for Animals Admitted to the Isolation Unit
A. Diarrheal Disorders in Horses
1. All horses ADMITTED to the hospital with a chief complaint of diarrhea or that have
diarrhea (acute or chronic) at the time of presentation to the hospital will be admitted to the
Isolation Unit.
2. Horses that develop diarrhea AFTER presentation to the hospital:
a) All horses (non-colic) with profuse projectile pipe stream diarrhea should be moved
to the Isolation Unit if the diarrhea lasts longer than 24 hours.
b) All horses that have had abdominal surgery for treatment of colic and develop
diarrhea lasting more than 72 hours should be moved to the Isolation Unit. All such
horses must remain in their stalls and these stalls must be "cordoned off" with dip buckets
with disinfectant outside stall anytime the horse has diarrhea.
c) All horses admitted as a medical colic/primary complaint of colic that does not
require surgical intervention will be moved to Isolation if they develop diarrhea.
3. Responsibilities of the clinician with any horse that develops diarrhea (including those with
colic):
a) Obtain a 30 gm aliquot of feces for salmonella culture on first day that diarrhea
develops, repeat daily for 5 days and then as directed by the clinician on the case.
b) Obtain white blood cell count to monitor for impending leukopenia that may suggest
Salmonellosis.
c) Cordon off the stall and place a dip bucket with disinfectant outside the stall.
d) Transfer the horse to the Isolation Unit and medicine service if fluid diarrhea persists
longer than 24 hours in non-colic cases and 72 hours in colic cases.
B. Salmonella Positive Horses
If a horse has a positive fecal culture, or rectal biopsy culture for salmonella, it will remain in the
Isolation Unit. Horses that are moved to the Isolation Unit do not return to the hospital.
C. Peritonitis
Horses with obvious peritonitis, a high white blood cell count, and a peritoneal fluid white blood
cell count of greater than 10,000, with soft stool, may be kept in the hospital. If fluid diarrhea
occurs, the horse should be transferred to Isolation.
D. Strangles
All horses with clinical evidence of strangles must be admitted to Isolation or not accepted into
the hospital.
E. Rhodococcus equi
May 2010
All foals or horses with Rhodococcus equi will be kept in the hospital because Rhodococcus equi
may be a normal inhabitant of the gastrointestinal tract and minimally contagious.
F. Rabies Suspects
Persons working directly on these animals must have been vaccinated with the appropriate
vaccine.
II. Transfer of Horses to Isolation
Once a horse is transferred to the Isolation Unit, the case and responsibility may be transferred to the
senior medicine clinician on duty. However, the surgeon on the case is encouraged to consult with
the medicine clinician on the postoperative care the horse may require.
III. Food Animals with Diarrheal and Infectious/Contagious Diseases
A. Any cow with pipestream diarrhea for more than 72 hours should be admitted to an Isolation
stall or the entranceway to the stall should be "cordoned off."
B. Any cow/calf that comes from a herd with a chief complaint of diarrhea or herd history of
diarrhea, including Johne's disease or Cryptosporidium should be admitted to an Isolation stall.
Calves with obvious fluid diarrhea should also be admitted to Isolation stalls.
C. Any cow admitted with a chief complaint of diarrhea should be admitted to an Isolation stall.
D. All cows with fluid projectile diarrhea should be cultured for salmonella on the day noted to
have diarrhea. If positive, they should be moved to Isolation.
E. Johne's Disease suspects are admitted to Isolation. If they are being treated with an
experimental drug and no longer culture positive, they may be turned out on pasture.
F. Mycoplasma, Pleuropneumonia-like Organisms (PPLO), Conjunctivitis in Goats -- must be
kept isolated from other goats and a sign placed on the stall stating that gloves must worn when
working with the animal.
G. Contagious Ecthyma animals must be kept in a stall with a sign stating infectious contagious
disease. Handle the animal only while wearing gloves and keep it isolated from other sheep and
goats.
IV. Implementation of Moving Animals to Isolation Unit
Once a horse is recognized to have fluid diarrhea, consideration should be given to transfer of the
patient to the Isolation Unit. At this point, the clinicians should discuss the merits of the case with
the medicine clinicians and render a decision about the patient's transfer to Isolation. In many
instances, the final decision will be based on clinical judgment and a review of the history and any
extenuating circumstances involving the case.
V. Procedure for Obtaining Radiographs in the Isolation Unit
A. All personnel involved with the procedure should be provided with plastic boots and
disposable gowns to be worn to confine pathogens to the Isolation area.
B. All cassettes should be placed in new plastic bags on arrival at the Isolation Unit before being
used. The cassettes should remain in the plastic bags until they are removed from the
Isolation area, at which time the plastic bags should be discarded.
May 2010
C. A similar plastic disposable bag should be placed over the radiograph machine when it is
removed from its carrying case and should remain on the machine until the radiograph
equipment is placed into its carrying case.
D. A lead radiology gown and a set of gloves should be identified for the Isolation Unit and
remain in the Isolation Unit rather than being transported between radiology and Isolation.
When the gown is being used, a disposable lab coat should be placed over the gown to
minimize contamination. Both gown and gloves should be cleaned with disinfectant after
each use.
E. Any wooden block used in an Isolation stall should be discarded after its use and not retained
in the Isolation Unit or returned to radiology.
F. All electrical cords and other equipment that may have become contaminated should be
cleaned with a sponge soaked in disinfectant. The wheels of carts must be sprayed with
disinfectant before being brought into the hospital.
G. The above procedure should be supervised by animal caretaking or technical staff so that all
procedures are carried out correctly and to insure that the disposable lab coats, plastic boots,
and plastic bags are provided at the appropriate time.
VI.
Use of the ECG in Isolation
A. All personnel should be provided with plastic boots and disposable lab coats.
B. The ECG machine and staff should approach the stall from the outside of the building and not
enter the stall. Personnel restraining the horse and attaching the leads should enter the stall in
the routine manner. If possible, the horse should be positioned near the door to enable the
ECG unit to remain outside the stall.
C. After the ECG has been obtained, the leads should be cleaned with a sponge soaked in
disinfectant, with particular care in cleaning the clips.
D. While taking the ECG, the paper from the machine should be caught in a plastic bag beside
the machine and not allowed to touch the ground.
E. When the machine is being removed from the Isolation area, an attempt should be made to
clean any gross contamination off the wheels and carts holding the machine. Cart wheels
should be sprayed with disinfectant before reentering the hospital.
F. Animal care technicians or clinicians should supervise the procedure, making certain that the
protocol is followed and that plastic boots and disposable coats are provided at the
appropriate time.
VII.
Procedure for Performing Endoscopic Examination on Horses in Isolation
A. All personnel handling the horse and equipment should be provided with plastic boots and
disposable gowns or lab coats.
B. The personnel performing the examination should approach the stall from the outside of the
building and should not enter the stall. Personnel restraining the horse should enter the stall
in the usual manner.
C. In the Isolation facility, a horse can be examined in the stocks if the stall is not occupied. The
restraint for the horse is determined by the senior clinician.
May 2010
D. After the endoscopic examination has been completed, the fiber-optic endoscope should be
cleaned according to the recommended procedure. In addition, the outside of the endoscope
should be soaked in a D-256 ® bath for fifteen minutes and rinsed with a 9% Sodium Chloride
bath.
E. Before the equipment is removed from the Isolation area, all gross contamination should be
removed from the wheels and body of the cart used for transport. Cart wheels should be
sprayed with disinfectant before reentering the hospital.
F. The twitch used to restrain the horse should be washed in a surgical scrub and immersed in a
Betadine® or Techni-Care® solution for approximately five minutes before being stored.
G. A member of the technical staff should be available to assist in the procedure and to ensure
that the protocol is followed and that all items are provided for completing the above steps.
Similar steps to those described above should be followed if an endoscopic examination has
been performed on a horse in the clinic with a nasal discharge or confirmed fungal or
bacterial infection of its upper respiratory tract.
VIII.
Policy for Surgical Procedures on Isolation Patients
The need to perform surgery on horses housed in Isolation rarely arises, but when it does, this protocol
should be followed. Any decision for surgery must be made by the senior clinicians in charge of the case.
The method used for moving a horse from Isolation to general surgery is described below. General
anesthesia should be induced in young animals in their Isolation stall before being transported by cart to
general surgery. In this way, contact with the ground is avoided and the spread of organisms is restricted.
The cost of disinfection procedures instituted after the surgery should be borne by the owner of the horse.
Standing surgeries may be done in the Isolation Unit if a minimum amount of equipment is required and
the horse can be adequately restrained in its stall. Standing procedures that require stocks and other forms
of restraint, or that require a large amount of surgical equipment and lights, should be performed in stocks
in Room 156. These cases should be handled in a similar fashion to those subjected to procedures under
general anesthesia.
IX.
Precautions for Surgery or Radiology/Ultrasound Examinations on Isolation Patients
(Includes all horses with diarrhea in Isolation and the Hospital.)
A. The primary clinician must make arrangements with the animal caretaking staff prior to
initiating either the surgical or radiologic/ultrasound procedure. They will help facilitate the
transportation of the animal and all aspects of the procedure. An additional cost of cleaning
and disinfecting will be added to the client's bill, and there will also be an additional cost
necessary to have a horse radiographed in the Radiology Suite.
B. The tail will be wrapped in a plastic bag.
C. The horse will be walked to the general surgery site from the Isolation Unit (down the alley
past the theriogenology room). One person is needed to lead the horse, and another person
must follow to clean up any fecal matter.
D. The surgical area, recovery stall, and any other applicable area of the hospital will be cleaned
and disinfected when the procedure is completed. These areas will be open for re-use
following complete drying. The cost of these extra services will be borne by the owner of the
animal.
X.
Environmental Culturing from the Hospital
May 2010
An environmental culturing program is always in progress. Stall areas are cultured between
patients. Culture records are kept electronically by the VDL.
XI.
Enterobacter
Enterobacter spp. is a common contaminant of wounds and is not considered a primary pathogen
but an opportunist.
XII.
Strangles
Environmental cultures for Strep. equi should be taken following the discharge from the Hospital
of a horse with strangles.
XIII.
Methicillin Resistant Staphylococcus aureus
A. Infection of hospitalized patients has occurred with methicillin resistant Staphlococcus aureus
(MRSA). Transmission of this organism is most commonly from patient to patient, however,
environmental sources and human carriers can sometimes be involved. Hands washing between
patients, wearing gloves when handling wounds and catheters, strict aseptic technique with
bandage changes and wound therapy, keeping all supplies off the floor or counters, are the main
ways of preventing infection in new patients. The organism is not highly resistant to disinfection,
but can be difficult to eliminate once infection has been established in wounds, joints, and veins.
Prevention is preferred.
B. Prevention and control measures:
1. Gloves must be worn. No wounds or catheters or bandages from infected patients should be
handled with bare hands.
2. Hands must be washed thoroughly between handling of all patients at all times. An
antibacterial hand washing soap with specific activity against MRSA will be identified and placed
in the clinic.
3. Warning signs will be posted on the stalls of all positive patients.
4. To prevent contamination of hands and colonization of the nasopharynx, respectively, gloves
and masks must be worn by human attendants when handling patients.
5. Positive patients should be isolated and be addressed last in the treatment schedule.
6. Treatment of known positive patients. Bandages of positive patients should be changed in the
stall if possible to avoid contamination of other areas of the hospital. Alternatively, one stall
could be designated as a treatment stall for these patients. All bandage materials for these
patients should be kept separate from other cases. Materials used from the clinic should not be
returned to the original containers, i.e., common scrub and alcohol containers should not be used.
Alternatively smaller amounts may be removed from primary containers all at once prior to
treating a horse and then any excess discarded.
7. Patients with wounds that develop an exudate following hospitalization should be considered
MRSA suspects and handled accordingly until proven otherwise via culture.
XIV.
Anesthesia
All anesthesia personnel must clean their equipment after use in a suitable disinfectant or
antiseptic solution and to ensure that the solution is rinsed off. Although problems rarely develop
with contaminated endotracheal tubes, they could spread serious and potentially fatal respiratory
conditions from one animal to another. Consideration should be given to gas sterilizing tubes that
have been used on animals with known infectious diseases of the upper and lower respiratory
tracts.