How Rabies Works

Rabies Risk: Bats vs. Dogs

Thanks to movies like "Old Yeller," most people are aware of at least some of the signs to watch for in a rabid beast. Though indicators like a foaming mouth and increased aggression from a previously friendly pooch are good things to be aware of, in many parts of the world, cases of dogs with rabies are much less frequent than they used to be. Today, many experts say that the real rabies threat comes from bats. Has the stereotypical harbinger of rabies, the mad dog, become antiquated? Are we in imminent danger from throngs of rabid, flying pests?

It's complicated, but in short, the answer to both questions is no. "Old Yeller" still provides an important message, but in the new millennium, the majority of rabies cases in the United States and other developed nations come from bats.

Most states in the U.S. now have laws mandating the regular vaccination of dogs and cats. Over the years, these laws have helped to significantly reduce the prominence of the rabies virus in man's best friend. In 2006, for example, only 0.011 percent of all rabies cases in the U.S. occurred in dogs [source: CDC].

That same year, bats made up an astounding 24 percent of all U.S. wildlife rabies cases. They are also to blame for two out of the three rabies-related deaths in 2006 [source: Blanton]. In fact, bats can take the blame for 28 out of the 37 confirmed cases of rabies in the U.S. since 1995. Not one came from an American dog [source: CDC].

In many ways, bats' success in taking the American-rabies crown makes sense. Bats have the ability to fly, making it easy for them to enter the upper level of a house or apartment. Their claws and teeth are small, so it's not unusual for people to wake up to find a bat in the room and not even be aware that they've been attacked.

Anyone who comes in contact with a bat should probably seek medical treatment. Even if there are no marks or puncture wounds, the virus still may be transferred. Both of the 2006 rabies fatalities that had encounters with bats believed the animals did them no harm [source: CDC].

Despite bats' potential to spread the disease, Americans and citizens of other developed nations are actually quite fortunate these flying mammals pose their greatest rabies risk. While it's expected that a few people in First World nations will contract the disease from bats, tens of thousands will do the same from dogs in other areas of the globe.