A Reminder about Rabies
By Dr. Paula Valeria, Great Lakes Equine Wellness Center, Inc.

Recent exposure of a horse in NE WI to a rabid bat should be a wake-up call for all horse owners.  Rabies is a fatal disease that is transferable to people and can be prevented in nearly 100% of cases by a safe and inexpensive vaccine.  So is your horse protected?

The recently exposed horse was in a typical boarding stable not far from the city—not living with wild animals in the national forest.  He was, as far as the owner knew, “up to date on his vaccines”.  She assumed Rabies was being given as part of the vaccine protocol, and never looked to see that it had not been on the list for several years.   The exposure happened in his stall in broad daylight with people all around—not at night in a pasture board situation.

Rabies is a viral disease affecting the central nervous system.  It can affect any mammal and is usually transmitted through a bite, although it can be also be transmitted through a scratch or through saliva coming in contact with broken skin or mucous membranes (e.g. the lining of the mouth, eyes or nose).  In Wisconsin bats and skunks are the most likely source of infection, although any animal can be affected.  The last few positive horse cases have been the bat strain.

An infected horse shows signs in 2-6 weeks, but it can take up to 12 weeks to show obvious clinical signs.  The clinical signs are widely variable.  Most commonly signs affect the central nervous system and include changes in behavior or demeanor.  Horses with rabies are often dull and depressed but can become aggressive and fearful.  Signs include low grade fever, lameness, muscle tremors, dilated pupils, photophobia, continual chewing and biting, hypersensitivity to stimuli, ataxia (incoordination), circling, headpressing, difficulty swallowing, convulsions and inability to rise.   Rabies signs can mimic many other neurologic diseases (e.g. tetanus, EHV-1, EEE, WEE, VEE, West Nile virus, EPM, botulism, lead poisoning and head or spinal cord trauma) so it can be very difficult to diagnose.  Definitive diagnosis can only be performed post-mortem.

There is no treatment for rabies.  Once clinical signs are apparent, the disease is always fatal.   Rabies is a reportable disease.  Horses showing clinical signs need to be examined by a veterinarian as soon as possible.  Because it is a zoonotic disease (disease transmissible to humans), it is important that contact with humans in suspect cases be minimized.

Luckily, very effective, safe and inexpensive vaccines are available to protect horses.  The Rabies vaccine produces a terrific serologic response even after a single dose.  It is recommended that adult horses be vaccinated once then boostered yearly.  Foals generally get their first dose after 6mo and then a booster 4-6weeks later.
Although owners can administer the vaccine, it is recommended that it be administered by a veterinarian as the state will consider owner vaccinated horses unvaccinated in the case of exposure to a rabid animal.

So double check the rabies status on your horse!  If it has been more than a year since your last vaccine make sure you call your veterinarian to have it boostered.  Rabies is a FATAL disease that humans can get from horses.  The vaccine is nearly 100% protective, inexpensive and safe.  Make sure you are protecting your horses and your family!