What Animal Rescue Advocates Need to Know About Rabies

Amidst new CDC regulations for dogs entering the US as a preventative measure against rabies and a recent case in which 12 puppies were euthanized after rabies exposure, you may be seeing a lot of discourse about rabies online and in the media.

While rabies is extremely serious, it is relatively rare in the US due to extensive regulation and vaccination. In this article, you'll find information on understanding and preventing rabies in relation to animal rescue.

In this article:

1. What is the rabies virus?

2. Incubation & symptoms

3. Rabies transmission

4. Testing for rabies

5. Vaccinating against rabies

6. Rabies quarantine

7. Other preventative measures against rabies

8. Sources

What is the rabies virus?

Rabies is a viral disease that affects the central nervous system. Once symptoms appear, there is no treatment, and rabies is fatal in nearly 100% of cases.

Incubation & symptoms

The length of incubation (the time between infection and the presentation of symptoms) varies by species. In dogs, incubation is typically 14-120 days; in cats, incubation is typically 21-56 days. The size of the animal, location of the infection site, and amount of rabies in the saliva of the original infected animal can all affect incubation.

The clinical signs of rabies progress in stages. First, the animal will experience the prodromal phase, when the animal displays a change in temperament. While the animal may become aggressive, it is also possible for a previously timid or wild animal to become much more friendly to humans.

Next, a dog will experience one of two stages:

• Furious rabies: this is what most people imagine when they think of a rabid animal. The animal presents aggressive and excitable behavior, may begin eating non-food items like rocks, and will eventually develop paralysis. This may include an inability to eat/drink and limb paralysis. Finally, the animal will experience violent seizures that eventually result in death.
• Dumb rabies: this is the most common form of rabies in dogs. The animal will experience progress paralysis of the limbs, distortion of the face, and an inability to eat/drink. The animal will become comatose and die.

In cats, rabies will almost always progress from the prodromal phase to furious rabies, including muscle spasms that affect the animals ability to eat/drink and excessive drooling. Finally, they will enter a paralytic stage, becoming comatose and dying.

Clinical signs may present differently in different species. Notably, humans often experience hydrophobia, a fear of water.

Rabies transmission

Rabies is spread through saliva. In most cases, it is transmitted through bite wounds, however, in rare cases, it may be spread by saliva coming into contact with an existing open wound, eyes, nose, or mouth.

Rabies is zoonotic, which means that it can pass between animals of different species (in this case, specifically mammals), including humans. Worldwide, 99% of rabies cases in humans are caused by contact with dogs, though cases involving cats have increased in recent years.

Testing for rabies

The only way to test for rabies is through examination of brain tissue. In order to obtain a tissue sample, the animal must first be euthanized. There is currently no way to test for rabies in a living animal.

Because rabies travels through the body over the course of days, weeks, or even months, it is possible for a brain tissue sample to come back negative for rabies even though the animal has been infected. The virus will first affect the tissue around the infection site, then the peripheral nerves, the spinal cord, and, finally, the brain.

Vaccinating against rabies

The best defense against rabies is vaccination. Thanks to routine vaccination of pets and wildlife in the US, the virus is rarely found in pets and humans.

Both dogs and cats should be vaccinated against rabies between 12-16 weeks old, with boosters typically administered every 1-3 years, depending on local ordinance.

Humans who have been exposed to rabies should immediately begin a vaccine protocol to prevent the virus from entering the nervous system. People who are at higher risk of exposure to rabies, such as those who work in wildlife control, should receive preventative vaccines.

Vaccine bait is often used to provide protection from rabies to wild animals. In the US, about 6.5 million doses of the vaccine are dropped each year, targeting animals like raccoons, coyotes, and foxes.

Rabies quarantine

An animal may be quarantined to watch for rabies in two situations: the animal bit someone, or the animal has been exposed to rabies. During a quarantine period, the animal can have no physical contact with other animals or humans.

An animal with no known exposure to rabies that has bitten someone is typically held for a 10-day quarantine. Most municipalities will require quarantine for any reported bite incident. In some cases, an owned, vaccinated pet may be allowed to serve an in-home quarantine. Otherwise, the animal will typically be held by local animal control or a veterinarian. If the animal does not present rabies symptoms within that 10 day period, they are considered non-contagious at the time of the bite.

A vaccinated animal who has been exposed to rabies will typically be given an immediate booster, then held for a quarantine of at least 30 days, though the period may last 120 days or more depending on the severity of the situation and local ordinance.

An unvaccinated animal who has been exposed to rabies may be eligible for a quarantine period after immediate vaccination, however, this is rarely a viable option. The quarantine period must last for at least 120 days, though may last much longer depending on the severity of the situation and local ordinance. Cost and logistics makes this unrealistic in most situations, but a quarantine of this length is often extremely detrimental to the animals mental health. Complete isolation for months at a time will often result in lifelong anxiety, fear of and/or inability to safely interact with others, and other potentially unsafe behaviors.

Other preventative measures against rabies

When it comes to protecting both pets and people in the rescue world, additional steps should be taken to prevent the spread of and exposure to rabies and other disease.

Pets should always receive appropriate health certificates before crossing state or international borders. Once they've reached their destination, pets should be held for at least 14 days before they are allowed to interact with other animals or the public. This period is critical for assessing overall health and watching for symptoms of various diseases.

All pets should be fully up-to-date on age-appropriate vaccinations before they are eligible for adoption and/or allowed to interact with other animal and the public.

Pets should never be allowed to interact with wildlife, both living and deceased. Any potential exposure should be reported immediately.

All bite incidents should be reported immediately, with a 10-day quarantine performed as required by local ordinance.

Sources

Rabies, World Health Organization

Rabies in Dogs, Krista Williams, BSc, DVM, CCRP; Tammy Hunter, DVM; Ernest Ward, DVM

Rabies in Cats, Krista Williams, BSc, DVM, CCRP; Malcolm Weir, DVM, MSc, MPH; Ernest Ward, DVM

Rabies, American Veterinary Medical Association

Taking the Bait: USDA Safeguards Wildlife Against the Rabies Virus, Alisha McDowell, APHIS Public Affairs Specialist