What animals get rabies?

Rabies affects only mammals. Mammals are warm-blooded animals with fur. People are also mammals. Birds, snakes, and fish are not mammals, so they can’t get rabies and they can’t give it to you. But any mammal can get rabies, including people. While rabies is rare in people in the United States, with only 1 to 3 cases reported annually, about 60,000 Americans get post-exposure prophylaxis (PEP) each year to prevent rabies infection after being bitten or scratched by an infected or suspected infected animal.

In the United States, more than 90% of reported cases of rabies in animals occur in wildlife. The wild animals that most commonly carry rabies in the United States are raccoons, skunks, bats, and foxes. Contact with infected bats is the leading cause of human rabies deaths in this country; at least 7 out of 10 Americans who die from rabies in the US were infected by bats. People may not recognize a bat scratch or bite, which can be very small, but these types of contact can still spread rabies.

Pets (like cats and dogs) and livestock (like cattle and horses) can also get rabies. Nearly all the pets and livestock that get rabies had not received vaccination or were not up to date on rabies vaccination. Most pets get rabies from having contact with wildlife.

Because of laws requiring dogs to be vaccinated for rabies in the United States, dogs make up only about 1% of rabid animals reported each year in this country. However, dog rabies remains common in many countries. Exposure to rabid dogs is still the cause of nearly all human rabies deaths worldwide. Exposure to rabid dogs outside the US is the second leading cause of rabies deaths in Americans.

How can you tell if an animal has rabies?

You can’t tell if an animal has rabies by just looking at it—the only way to know for sure if an animal (or a person) has rabies is to perform laboratory testing. However, animals with rabies may act strangely. Some may be aggressive and try to bite you or other animals, or they may drool more than normal. (This is sometimes shown in movies as animals “foaming at the mouth.”) But not all animals with rabies will be aggressive or drooling. Other animals may act timid or shy, move slowly or act tame, or let you get close to them. Because that’s not the way wild animals usually act, you should remember that something could be wrong. Some animals may not appear ill. For the health and safety of wildlife, your pets, and yourself, leave wild animals alone, including baby animals.

The best thing to do is to never feed or approach a wild animal. Be careful of pets that you do not know. If you see a stray dog or cat, don’t pet it. This is especially important if you are traveling in a country where rabies in dogs is common. And if any animal is acting strangely, call your local animal control officer for help. Some things to look for are:

• General sickness
• Problems swallowing
• Excessive drool or saliva
• An animal that is overly aggressive
• An animal that bites at imaginary objects (sometimes called “fly biting”)
• An animal that appears tamer than you would expect
• An animal that’s having trouble moving or may even be paralyzed
• A bat that is on the ground

How can you prevent rabies in animals?

There are several things you can do to protect your pet from rabies. These include making sure your pets get regular rabies vaccines, keeping pets away from wild animals, spaying or neutering pets, and calling animal control to remove stray animals from your neighborhood. Many states also are vaccinating wild animals (mainly raccoons) to prevent the spread of rabies. Instead of trying to catch every animal and give it a shot, they use a vaccine in a special type of food that works when the animal eats it. The food is put out where animals are likely to find it. Sometimes airplanes and helicopters are used to get the food into places that are hard to reach on foot or with a truck.

When should you see a doctor?

If you’ve been in direct physical contact with any wildlife or unfamiliar animals, particularly if you’ve been bitten or scratched, you should talk with a healthcare or public health professional to determine your risk for rabies or other illnesses. One important factor in deciding if you should receive rabies vaccination (post exposure prophylaxis) will be if the animal you were exposed to can be found and tested for rabies or held for observation. If you need rabies vaccination, it should be started soon after exposure; so talk to a healthcare provider right away to determine if you need it.

There are several things you can do to protect your pet from rabies.

First, visit your veterinarian with your pet on a regular basis and keep rabies vaccinations up-to-date for all cats, ferrets, and dogs.

Second, maintain control of your pets by keeping cats and ferrets indoors and keeping dogs under direct supervision.

Third, spay or neuter your pets to help reduce the number of unwanted pets that may not be properly cared for or vaccinated regularly.

Finally, call animal control to remove all stray animals from your neighborhood since these animals may be unvaccinated or ill.

The importance of vaccinating your pet

While wildlife are much more likely to be rabid than are domestic animals in the United States, people have much more contact with domestic animals than with wildlife. Your pets and other domestic animals can be infected when they are bitten by rabid wild animals, and this type of “spillover” increases the risk to people.

Keeping your pets up to date on their rabies vaccination will prevent them from acquiring the disease from wildlife, and thereby prevent possible transmission to your family or other people.

Moving out of the United States

If you are bringing your pet into the United States, you may be subject to CDC regulations that govern the importation of animals capable of causing human disease. (For example, dogs coming from countries considered high risk for importing dog rabies must have a valid rabies vaccine certificate to enter.)

If you are planning to move out of the country and take your pets with you, you should consult with the embassy of your destination country to see what regulations they have for importing pets.

Dogs, Cats, and Ferrets

Rabies virus can be excreted in the saliva of infected dogs, cats, and ferrets during illness and/or for a few days before illness or death. A healthy dog, cat, or ferret that bites a person should be confined and observed daily for 10 days. Confinement should be performed in coordination with public health authorities. To avoid mistaking the signs of rabies for possible side effects of vaccination, administration of rabies vaccine to the animal is not recommended during the observation period.

If the confined animal develops any signs of illness, it should be evaluated by a veterinarian. Any illness in the animal should be reported immediately to the local health department. If the animal develops signs suggestive of rabies, it should be euthanized by an animal health professional and the head submitted to a diagnostic laboratory for testing.

Any stray or unwanted dog, cat, or ferret that bites a person may be euthanized immediately by an animal health professional and the head should be submitted for rabies testing.

Other Animals

Other biting animals that might have exposed a person to rabies should be reported immediately to the local health department. Management of biting animals other than dogs, cats, and ferrets depends on:

• The species
• The circumstances of the bite
• The epidemiology of rabies in the area
• The biting animal’s history and current health status
• The animal’s potential for exposure to rabies

Previous rabies vaccination of these animals might not preclude the necessity for euthanasia and testing.

For clients whose animal has up-to-date rabies vaccinations

Dogs, Cats, and Ferrets

Dogs, cats, and ferrets that are currently vaccinated with a USDA-licensed rabies vaccine should be revaccinated immediately, kept under the owner’s control, and observed for 45 days. If the animal under observation develops any signs of illness, it should be evaluated by a veterinarian. Any illness in an animal under observation should be reported immediately to the local health department. If the animal under observation develops signs suggestive of rabies, it should be euthanized by an animal health professional and its head submitted to a diagnostic laboratory for testing.

Livestock

If up to date for rabies vaccination, livestock that have been exposed to a rabid animal should be revaccinated immediately with a rabies vaccine and observed for 45 days.

Handling and consumption of uncooked tissues from exposed animals could carry a risk for rabies transmission. Persons handling the carcasses and tissues of exposed animals should use appropriate barrier precautions.

State and local public health authorities, state meat inspectors, and the USDA Food Safety and Inspection Service should be notified if exposures occur in animals intended for commercial use. Animals should not be presented for slaughter in a USDA-regulated establishment if such animals originate from a quarantine area and have not been approved for release by the proper authority. If an exposed animal is to be custom slaughtered or home slaughtered for consumption, it should be slaughtered immediately after exposure using appropriate barrier precautions, and all tissues should be thoroughly cooked.

Other Animals

Other mammals (those not specifically mentioned above) that have been exposed to a rabid animal should be euthanized immediately. Animals maintained in USDA-licensed research facilities or accredited zoological parks can be evaluated on a case-by-case basis.

For clients with animals OVERDUE for booster rabies vaccinations

Dogs, Cats, and Ferrets

Dogs, cats, and ferrets that are overdue for a booster vaccination and that have appropriate documentation of having received a USDA-licensed rabies vaccine at least once previously can be revaccinated, kept under the owner’s control, and observed for 45 days. Any illness in an animal under observation should be evaluated by a veterinarian and reported immediately to the local health department. If the animal under observation develops signs suggestive of rabies, the animal should be euthanized by an animal health professional and its head submitted to a diagnostic laboratory for testing.

In instances where a dog or cat is overdue for a booster vaccination but without appropriate documentation of having ever received a USDA-licensed rabies vaccine, local public health authorities should be consulted to determine the best course of action.

Livestock

Livestock overdue for a booster vaccination should be evaluated on a case-by-case basis.

Other Animals

Other mammals (those not mentioned above) exposed to a rabid animal should be euthanized immediately. Animals maintained in USDA-licensed research facilities or accredited zoological parks can be evaluated on a case-by-case basis.

For a client’s animal that has NEVER been vaccinated against rabies

Dogs, Cats, and Ferrets

Following an exposure to rabies, dogs, cats, and ferrets that have never been vaccinated against rabies should be euthanized immediately by an animal health professional because there are no USDA-licensed biologics for postexposure prophylaxis in previously unvaccinated domestic animal. The vaccine alone will not reliably prevent the disease in these animals.

If the owner is unwilling to have the animal euthanized, the animal should be placed in strict quarantine for 4 (dogs and cats) or 6 (ferrets) months. A rabies vaccine should be administered at the time of entry into quarantine. Every effort should be made to vaccinate the animal within 96 hours of exposure.

Livestock

In the event of an exposure to rabies, unvaccinated livestock should be euthanized immediately. If the animal is not euthanized, it should be kept under close observation for 6 months. Any illness in an animal under observation should be reported immediately to the local health department. If the animal develops signs suggestive of rabies, it should be euthanized and tested.

Other Animals

Other mammals exposed to a rabid animal should be euthanized immediately. Animals maintained in USDA-licensed research facilities or accredited zoological parks should be evaluated on a case-by-case basis.

Rabies virus causes an acute encephalitis in all warm-blooded hosts and the outcome is almost always fatal. The first symptoms of rabies may be nonspecific and include lethargy, fever, vomiting, and anorexia. Signs progress within days to cerebral dysfunction, cranial nerve dysfunction, ataxia, weakness, paralysis, seizures, difficulty breathing, difficulty swallowing, excessive salivation, abnormal behavior, aggression, and/or self-mutilation.

What samples are needed for rabies testing?

Rabies testing should be performed in accordance with the established national standardized protocol for rabies testing by a qualified laboratory that has been designated by the local or state health department. Euthanasia should be accomplished in such a way as to maintain the integrity of the brain so that the laboratory can recognize the anatomical parts.

Except in the case of very small animals, such as bats, only the head or brain (including brain stem) should be submitted to the laboratory. Fresh frozen (unfixed) tissues are preferred for rabies diagnosis. Refrigerated samples are not preferred and should be used only as a last resort when shipping on dry ice is not possible.

Chemical fixation of tissues should be avoided to prevent substantial testing delays and because it might preclude reliable testing. Questions regarding testing of fixed tissues should be directed to the local rabies laboratory or public health department.

What tests are performed to diagnose rabies?

The direct fluorescent antibody test (dFA) is the test most frequently used to diagnose rabies. This test requires brain tissue from animals suspected of being rabid and can only be performed post-mortem. This test has been thoroughly evaluated for more than 40 years and is recognized as the most rapid and reliable of all the tests available for routine use. All rabies laboratories in the United States perform this test on animals suspected of having rabies. Other tests for diagnosis and research such as electron microscopy (EM), histologic examination, immunohistochemistry (IHC), RT-PCR, and isolation in cell culture are useful tools for studying the virus structure, histopathology, molecular typing, and virulence of rabies viruses.

A diagnosis of rabies can be made after detection of rabies virus from any part of the affected brain, but in order to rule out rabies, the test must include tissue from at least two locations in the brain, preferably the brain stem and cerebellum.

The test requires that the animal be euthanized. The test itself takes about 2 hours, but it takes time to remove the brain samples from an animal suspected of having rabies and to ship these samples to a state public health or veterinary diagnostic laboratory for diagnosis.

In the United States, the results of a rabies test are typically available within 24 to 72 hours after an animal is collected and euthanized. Because rabies exposure to suspect animals is a medical urgency, but not an emergency, testing within this period is more than adequate for determining if a person was exposed to a rabid animal, and requires rabies postexposure vaccinations.

Approximately 120,000 animals or more are tested for rabies each year in the United States, and approximately 6% are found to be rabid. The proportion of positive animals depends largely on the species of animal and ranges from <1% in domestic animals to >10% of wildlife species.

Based on routine public health surveillance and pathogenesis studies, we have learned that it is not necessary to euthanize and test all animals that bite or otherwise potentially expose a person to rabies. For animals with a low probability of rabies such as dogs, cats, and ferrets, observation periods (10 days) may be appropriate to rule out the risk of potential human rabies exposure.

Consultation with a local or state health official following a potential exposure can help determine the best course of action based on current public health recommendations.

An animal can be considered immunized within 28 days after initial vaccination, when a peak rabies virus antibody titer is reached. An animal is considered currently vaccinated and immunized if the initial vaccination was administered at least 28 days previously or booster vaccinations have been administered in accordance with recommendations. Because a rapid anamnestic response is expected, an animal is considered currently vaccinated immediately after a booster vaccination.

Vaccination schedules

Vaccination of dogs, ferrets, and livestock can be started at no sooner than three months of age. Some cat vaccines can be given as early as two months of age. Regardless of the age of the animal at initial vaccination, a booster vaccination should be administered one year later.

Dogs, Cats, and Ferrets

All dogs, cats, and ferrets should be vaccinated and revaccinated against rabies according to product label directions. If a previously vaccinated animal is overdue for a booster, it should be revaccinated. Immediately following the booster, the animal is considered currently vaccinated and should be placed on a vaccination schedule according to the labeled duration of the vaccine used.

Livestock

Consideration should be given to vaccinating livestock that are particularly valuable. Animals that have frequent contact with humans (e.g., in petting zoos, fairs, and other public exhibitions) and horses traveling interstate should be currently vaccinated against rabies.

Confined Animals

Wild

No parenteral rabies vaccines are licensed for use in wild animals or hybrids (i.e., the offspring of wild animals crossbred to domestic animals). The AVMA has recommended that wild animals or hybrids should not be kept as pets.

Maintained in Exhibits and in Zoological Parks

Captive mammals that are not completely excluded from all contact with rabies vectors can become infected. Moreover, wild animals might be incubating rabies when initially captured; therefore, wild-caught animals susceptible to rabies should be quarantined for a minimum of 6 months. Employees who work with animals at exhibits and in zoological parks should receive preexposure rabies vaccination. The use of pre- or postexposure rabies vaccinations for handlers who work with animals at such facilities might reduce the need for euthanasia of captive animals that expose handlers. Carnivores and bats should be housed in a manner that precludes direct contact with the public.

Serologic titers

Titers do not directly correlate with protection because other immunologic factors also play a role in preventing rabies, and the ability to measure and interpret those other factors are not well developed. Therefore, evidence of circulating rabies virus antibodies should not be used as a substitute for current vaccination in managing rabies exposures or determining the need for booster vaccinations in animals.

Interstate travel

Before interstate movement (including commonwealths and territories), dogs, cats, ferrets, and horses should be currently vaccinated against rabies.

Animals might be displaced during and after manmade or natural disasters, and they might require emergency sheltering. Animal rabies vaccination and exposure histories often are not available for displaced animals, and disaster response can create situations in which animal caretakers might lack appropriate training and previous vaccination.

In such situations, the following rabies prevention and control measures should be used to reduce the risk for rabies transmission and the need for human postexposure prophylaxis.

• Coordinate relief efforts of persons and organizations with the local emergency operations center before deployment
• Examine each animal for signs of rabies at a triage site
• Isolate animals exhibiting signs of rabies, pending evaluation by a veterinarian
• Ensure that all animals have a unique identifier
• Administer a rabies vaccination to all dogs, cats, and ferrets unless reliable proof of vaccination exists
• Adopt minimum standards for animal caretakers that include personal protective equipment, previous rabies vaccination, and appropriate training in animal handling
• Maintain documentation of animal disposition and location (e.g., returned to owner, died or euthanized, adopted, relocated to another shelter, address of new location)
• Provide facilities to confine and observe animals involved in exposures
• Report human exposures to appropriate public health authorities.