What is it, and why do we vaccinate for it?

Dr. Shannon Holland

By Dr. Shannon Holland

03 Jun 2022

What is Rabies?

Rabies is a disease that is caused by the virus of the same name. Rabies only infects mammals. The virus is carried in the saliva of an infected mammal. When they bite or scratch another animal or person, they can get that saliva into the victim's bloodstream. The rabies virus then travels up the nerves until it reaches the central nervous system (brain & spinal cord). Once it reaches the brain it starts to cause symptoms that eventually lead to death. A person or animal with the virus can take a few weeks or up to 3 months to develop symptoms.

Rabies can cause hypersalivation or drooling, lethargy, aggressive behavior, stumbling, difficulty eating and drinking (this is where the term hydrophobia came from), coma and eventually death.

One common misconception is that it is obvious when an animal has rabies. The common belief is that an animal with rabies will be very aggressive and foaming at the mouth; however, this is not nearly as common as people think. They often show symptoms that are not easily distinguished from other illnesses. Some animals may not have any obvious symptoms in the early stages of the disease. However, they can still infect other animals or people. It's for this reason that if an animal ever bites you or your pet, you should seek immediate medical attention. Even if that animal is not exhibiting classic rabies symptoms. You should also immediately call you local animal control so that they can properly handle the animal and guide you on care.

The most common wild animals that transmit rabies to people are skunks, bats, foxes, racoons and coyotes. Domesticated dogs and cats are also very common links in the chain of transmission of rabies to people.

Effectiveness of Vaccines and Public Programs

In the United States we see an average of around 5,000 cases of rabies in animals annually. In humans it is a mere 1 to 2 cases in the same amount of time.1 These numbers are due in large part to the variety of public programs and laws pertaining to rabies. The introduction of these measures in every state in the U.S. has caused a tremendous reduction in cases over the past 100 years.

Today, all states in the U.S. require cats & dogs to be vaccinated for rabies. They also require regular booster rabies vaccines. If an animal bites a person or if a pet has potential rabies contact, there are strict quarantine laws that the local governments have in place. In addition, many areas of the country have programs to vaccinate certain wildlife like coyotes.

In addition to reducing wildlife and pets as vectors for the virus, we in America are also are more likely to have access to effective post-exposure medical treatment. The post exposure vaccine is a highly effective if given prior to symptoms developing. It is given after any potential or known rabies exposure. There is a commonly held belief that the post exposure vaccine is given through the stomach or around the belly-button. This is not the case. It is a series of shots that you get in your arm and is not very different from any other vaccine you would receive. It is important to note that rabies is 100% preventable with the post exposure vaccine. 60,000 people receive the post exposure vaccine every year in the United States. Without this vaccine treatment, Rabies is a 100% fatal disease in people.1 This means that a person who is exposed to rabies is almost guaranteed to die from it if they don't receive the post exposure vaccine and almost guaranteed to not have any ill effects if they do receive the post exposure vaccine.

How is rabies most commonly transmitted?

Of the few cases of rabies in the United States, the majority are people who traveled internationally and were exposed to a rabid animal. Of those that did not travel, 70% were caused by bats. Bats do not often show symptoms of rabies and their bites are small. It can be hard to ever know if you have a bat bite as the wound they leave can be almost invisible or often mistaken for an insect bite such as that of a mosquito. If you ever find a bat in an area where you or someone else was sleeping, unable to move, or not aware of the bat, then you should have animal control catch the bat for testing and immediately begin post exposure vaccines. Don't release the bat even if you do not see a bite!

Other animals can also transmit rabies in the United States. It is not uncommon to hear of someone that was bitten by a small feral kitten that had rabies, dogs fighting with rabid racoons or skunks, cats that have killed a bat that tested positive for rabies. Anytime you have contact with an animal and you are not sure, then just ask your local animal control and your doctor.

A good rule of thumb to follow is to never touch a wild animal. Wild animals will generally avoid being approached, so if you CAN touch a wild animal then you should assume that there is something wrong with it. Healthy, normal wild animals do not want to be touched!

Worldwide, rabies kills around 59,000 people every year. In other countries, dog bites are the primary cause. Rabid dog bites are responsible for 99% of worldwide rabies deaths in people.2 This is largely due to the numerous populations of feral dogs, poor vaccination coverage, lack of medical knowledge, and lack of access to post exposure treatment.

Important Takeaways

  • Rabies is a major concern worldwide

  • If you ever have exposure (bite, scratch, or uncertain) to an animal, contact your local animal control and your medical doctor

  • Rabies is 100% preventable with proper post exposure vaccinations

  • Rabies is 100% fatal once symptoms develop

  • We have strict laws about rabies vaccinations and quarantine in our domestic pets for the health of people and our pets

More Information


1CDC - Rabies in the U.S.

2CDC - Rabies around the World