Managing a Rabid Horse

Is it colic, or could it be rabies? The horse with rabies is extremely dangerous to himself, other animals, and humans. Rabies is a fatal viral disease of mammals that can be spread to humans through bites, licks, or through contact with the victim's mucous membranes or an existing wound. Horse owners must use extreme caution if rabies is suspected, and a veterinarian should be called immediately. During his presentation at the 2003 American Association of Equine Practitioners' convention, Tomas Gimenez, Dr.Med.Vet., professor at Clemson University, informed veterinarians of how to manage a potentially rabid horse.

Gimenez explained how the rabies virus (genus Lyssavirus) enters the victim's body either through a wound or through contact with saliva or mucous membranes. It then replicates (reproduces itself) in the local area, invading local nerves. Localized redness or itchiness might be seen, although many times there are no clinical signs at this stage. As the disease progresses, the virus enters the central nervous system.

Clinical signs might not show up for two weeks or for as long as six months after infection is introduced. Signs include fever, lack of appetite, lameness, colic, facial nerve paralysis, weakness, restlessness, a progressing lack of coordination, self-mutilation, aggressiveness, vocalization, drooling, and paralysis. If a veterinarian confirms rabies, then he must call the state veterinarian's office, county animal control, and the county health department immediately. Euthanasia is inevitable, and anyone who has come in contact with the horse must undergo treatment for rabies.

Owners should remember that rabies is preventable by vaccination. Horses older than three months of age should be vaccinated annually by a veterinarian. In order to be effective, the vaccine must be given before exposure.

Suspected Rabies
If a horse is showing signs of rabies, direct contact with the horse should be avoided. The rabid horse can show either non-aggressive, "dumb" behavior, or be aggressive and extremely dangerous, said Gimenez. All personnel should wear coveralls with long sleeves, boots, and double gloves. Clothing, equipment, and any other objects that come in contact with the horse should be disinfected with bleach, and all facilities should be cleaned thoroughly. Saliva and mucosal surfaces and secretions should be avoided, but blood and urine do not contain the virus.

He advised that the horse's behavior be photographed or captured on video before euthanasia and sent to the state veterinarian's office to aid in the final diagnosis of the disease. Confirmation of the disease must be made by examining the victim's brain tissue after death.

In addition to managing the rabid horse, all other animals on the property, such as dogs, cats, other horses, cattle, etc., should be isolated and quarantined whether they have been vaccinated or not.

Standard Operating Procedure
Gimenez has developed a Standard Operating Procedure (SOP) for euthanizing of the rabid horse. A horse with signs of aggressive rabies should be kept in a separate enclosure, either a stall or a secure pen (one from which he can't escape or destroy). Then the veterinarian will sedate the horse with a dart gun or jab stick. Because of the amount of sedative needed, the horse might require more than one dart, said Gimenez.

Once the horse is heavily sedated and down, the team will secure him with ropes, being careful to avoid flailing legs; even the sedated horse can be dangerous. The front legs are tied together and the hind legs are tied together and anchored to a secure object, such as a vehicle or a tree. The horse's head is then secured, and the horse's mouth will be tied shut with a loop right behind his nostrils.

The veterinarian then carefully draws a blood sample for analysis. If rabies is not the problem, then the blood sample can be tested for other diseases such as Eastern equine encephalitis, Western equine encephalitis, and West Nile virus. The horse is then euthanized. A horse should never be euthanized by firearm, since this will destroy the brain tissue that is needed for a diagnosis.

The veterinarian will either send the head or the entire horse to the veterinary diagnostic laboratory. The horse's body can be buried following appropriate recommendations for the burial of large animals, or incinerated at the diagnostic laboratory. Gimenez recommended that the head be removed with a hacksaw to minimize aerosolation (dispersion into the air) of the virus. The horse's body should immediately be burned or buried.

"This Standard Operating Procedure provides a safe and suitable means of euthanizing large animals suspect of having rabies while minimizing exposure for personnel," he concluded.

Case Study
Gimenez gave attendees a glance into his experience of dealing with a rabid horse though a 12-minute video of a case with which he helped. A 5-year-old Arabian mare was diagnosed with colic by a veterinarian. When the horse did not get better, a second veterinarian was called. By that time the horse was very distraught, painful, aggressive, and she eventually began self-mutilating herself. Gimenez, the local practitioner, and others were able to sedate the horse and euthanize her. She had not been vaccinated.

About the Author

Sarah Evers Conrad

Sarah Evers Conrad has a bachelor’s of arts in journalism and equine science from Western Kentucky University. As a lifelong horse lover and equestrian, Conrad started her career at The Horse: Your Guide to Equine Health Care magazine. She has also worked for the United States Equestrian Federation as the managing editor of Equestrian magazine and director of e-communications and served as content manager/travel writer for a Caribbean travel agency. When she isn’t freelancing, Conrad spends her free time enjoying her family, reading, practicing photography, traveling, crocheting, and being around animals in her Lexington, Kentucky, home.

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