Minnesota Horse Tests Positive for Rabies

A horse residing in Mower County, Minn., tested positive for rabies on Jan. 4, making it the first rabies case confirmed in that state in 2013, according to a Jan. 9 post on the University of Minnesota Equine Center Facebook page.

According to the post, the horse's owner noticed the animal had become weak and was having difficulty rising last week. The horse began head pressing and falling and eventually became unable to stand.

The animal's rabies vaccination status is unknown, the post read, and authorities are investigating possible disease exposure in the property owner's other horses, cattle, and dog.

Rabies--a zoonotic disease that can be spread from animals to humans--is caused by a lyssavirus that affects the neurologic system and salivary glands. Horses are exposed most commonly through the bite of another rabid animal.

Rabies' clinical signs are variable and can take up to 12 weeks to appear after the initial infection. Although affected horses are sometimes asymptomatic, an infected horse can show behavioral changes such as drowsiness, depression, fear, or aggression. Once clinical signs appear, there are no treatment options.

Rabies can only be diagnosed postmortem by submitting the horse's head to a local public health laboratory to identify the rabies virus using a test called fluorescence antibody. Thus, ruling out all other potential diseases first is very important in these cases to avoid potentially unnecessary euthanasia.

Commercially available rabies vaccines are safe and effective. According to the American Association of Equine Practitioner's vaccination guidelines, adult horses should be vaccinated annually and mares in foal should be vaccinated four to six weeks prepartum or before breeding. Veterinarians should administer an initial series of three vaccines to foals and weanlings younger than 12 months of age; exact timing depends on the mare's vaccination status. Thereafter, horses should be vaccinated annually.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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