Although rabies certainly does affect humans, it's largely a disease that exists and spreads among animals. Most people are knowledgeable enough about the disease to be wary of an animal that's foaming at the mouth, but there are many other symptoms an infected creature may exhibit. In fact, some rabid animals, including those who have contracted the "dumb" form of the disease, never foam at the mouth. Almost all cases of rabies in humans are contracted from an infected animal, so it's important to know what to look for.
Rabid animals often:
- Are fully or partially paralyzed
- Experience a loss of appetite
- Exhibit strange behaviors, such as snapping at the air or turning in circles
- Are nocturnal animals who wander during the day -- or diurnal animals who start going out at night
- Drool excessively
- Are wild animals who show no fear of humans
- Exhibit symptoms of pica (eating substances that aren't food, such as rocks, dirt or wood)
- Have sporadic changes in mood or behavior
- Appear to be restless or aggressive
- Are obviously disoriented
- Acquire a change in voice (you may notice a change in the pitch and tone of your dog's bark, for example)
Rabies typically infects a variety of animals that vary by region. In the United States, raccoons are the most common carriers of the disease, but bats more often transfer it to humans [source: CDC]. Skunks and foxes are also frequent vectors for the virus, but it has been found in everything from woodchucks to chimpanzees. A good rule of thumb: If an animal is exhibiting unusual behavior, try to avoid it and contact your local animal control office as soon as possible.
Unfortunately, it's often difficult to tell if an animal is just acting strangely or actually poses a real threat. A dog may turn around in circles and snap at the air just because it feels like it, not because it's rabid.