Mountain lions, and cattle, and skunks, oh my! These are some of the species in this area that have recently been confirmed to be infected with rabies. We all know we are required to vaccinate our dogs, cats and ferrets against rabies, but we see the disease so infrequently in this part of the country that we probably don’t give it much thought otherwise.
Rabies is caused by a virus. That means that antibiotics, which work against bacteria only, will not help an infected individual. Although there have been a few very rare cases of recovery from rabies described in people and possibly in animals too, once the symptoms start, the disease is essentially 100% fatal.
Wildlife functions as the source of rabies in the environment. Bats are the most common carriers in the western United States, but skunks, foxes and raccoons are also common carriers in other parts of the country. Recently we have had skunk rabies detected in eastern El Paso County.
Unlike most viruses which tend to be quite particular about what species they infect, rabies seems able to cause infection in almost any type of mammal. The most common method of transmission is through bite wounds inflicted by sick animals. We tend to think of dogs as being the domestic animal most often affected, but a surprisingly larger number of livestock are affected each year. Horses and cattle get bitten when they stick their noses down to investigate a sick bat flopping on the ground in the middle of the day, or check out a wobbly skunk wandering through their pen.
The virus likes nerves, so when it is injected into the new host’s body through a bite wound it first travels to the nerves in the area of the bite, then migrates along them until it reaches the brain. Once inside brain the virus starts causing the symptoms that inevitably lead to death. The first symptoms are vague and non-specific. The animal may seem agitated, unwilling to eat or it may salivate excessively. Within 5 days the symptoms may progress to “Furious” rabies--the phase where wandering, aggression, seizures, and dementia can be seen. Within another 5 days animals can progress to “Dumb” rabies, where mental dullness, urinary incontinence and death follow. The progression of the disease can be extremely variable, and not all phases are seen in all affected animals. Cats are more likely to develop furious rabies, and horses are more likely to develop only dumb rabies. The amount of time from first symptoms to death is usually 14 days or less. This is why animals who have bitten someone are quarantined. A rabid animal will be showing obvious symptoms or die within a 10 day time frame, thus letting us know if the bitten person has been exposed to rabies. The only way to confirm rabies infection requires looking for characteristic changes in brain tissue under a microscope, and that test cannot be performed on a live animal. Because not all animals that bite are rabid, it is not reasonable to euthanize every biter in order to test it.
Fortunately the rabies vaccines that are commonly available and legally required for dogs, cats, and ferrets are very effective at preventing the disease. In order to legally qualify as vaccinated the shot must be given by a veterinarian to ensure that the vaccine had been handled and stored appropriately and administered correctly. A properly vaccinated pet should never have to worry about dying from or passing on rabies.