by Whit Gibbons

February 25, 2007

I hear more and more people mentioning coyotes in parts of the South where they were either extirpated more than a century ago or never occurred to begin with. As we alter the environment, some animals learn to adapt. Coyotes, along with pigeons and rats, are among them. People generally associate coyotes in suburbia with the disappearance of outdoor house cats or small dogs. You can add rabies to your list of concerns about these wily members of the dog family.

Since the first use of the English word "rabies" in 1661, thousands of people and probably millions of other animals have died from the disease. The rabies virus, usually introduced by saliva during biting, can also enter the body through a cut or through mucous membranes in the mouth. Because of paralyzed throat muscles, rabies victims have difficulty swallowing water. "Hydrophobia," which means fear of water, is another name for rabies. Excessive drooling can also occur with rabies, leading to the "foaming at the mouth" symptom.

The rabies virus multiplies in the nervous system. Symptoms usually develop within three months but can appear in only a few days or take as long as a year to develop, probably because of the variability of the infection's rate and pattern of progress in the nervous system. A person with rabies can display a wide variety of symptoms, including fever, tightening of the neck muscles, difficulty in swallowing, and mood changes. Why different expressions of rabies symptoms occur is not clear but may be due in part to different viral strains.

What animals can get rabies? Any warm-blooded animal, including coyotes, can harbor the virus, but the most common reservoirs in the United States are foxes, skunks, raccoons, and bats. The association with bats can be a particularly serious problem in tropical America where rabid vampire bats prey on sleeping cattle, causing paralysis. Horses can also get rabies.

Unprovoked biting by animals is one sign of rabies and is a cause of spreading the disease among the same or different species. Rabies is less common among the rodents, including rats and mice. It's nice to know there is at least one insidious, transmittable disease in which rats do not play a major role. Although birds are theoretically susceptible, the incidence of rabies is rare, although I once heard of a rabid chicken. Possums supposedly do not get rabies. Also, I know of no records of marine mammals with rabies, but who knows what made Moby Dick act the way he did?

Recovery from untreated rabies is extremely rare in humans and other animals: most victims die within a few days after manifesting symptoms. Fortunately, rabies treatment for humans is highly effective if administered during the early stages. Rabies should not be viewed as a scourge of the animal kingdom; most wild animals are going to die a natural death in some unpleasant way. But when rabies gets close to home, literally, we need to take precautions. All domestic animals and humans have the potential to get rabies. The risk can be reduced considerably if proper vaccination procedures are followed.

A Centers for Disease Control report indicates that rabid bats have been documented to occur in all of the 48 conterminous states, and more than 20 people have died from contact with rabid bats. Such a statistic is in no way an indictment of free-ranging bats, which are beautiful animals to watch in flight. But one message is clear: if you find a bat on the ground or in a house, don't let it bite you.
All domestic dogs and cats should be vaccinated, especially those that are likely to go outside or come in contact with other animals. In most parts of the United States, rabies vaccinations for both dogs and cats are required by law. I don't like unnecessary regulations, but this law is unquestionably a good one.
I once heard someone espouse the hare-brained idea that we should start vaccinating wild animals to prevent rabies epidemics among them. Such a plan would be absurd. We should all have our pets vaccinated at the vet's or a rabies clinic, but let's leave the wild animals to take care of themselves.

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