Rabies is caused by a bullet-shaped virus that belongs to the family Rhabdoviridae. It causes a devastating neurological disease that affects the brain, causing symptoms that are similar to meningitis. Once symptoms develop, the disease is always fatal.
What is rabies?
Rabies is an ancient scourge that has been around for centuries and continues to appear throughout the world. The disease affects all mammals, most commonly wild animal populations, but also afflicts dogs, cats, and people. Since 1884 when Louis Pasteur developed the first vaccine, rabies has been preventable. Some areas such as Hawaii and Great Britain eliminated the disease using strict quarantine protocols.
Rabies still appears today in pets or people as a result of disease spillover from wild animals and parallels the incidence of rabies in these feral reservoirs. Animals most often associated with the disease include
- Raccoons in the northeastern United States (New York, Connecticut, New Jersey, Maryland, and spreading)
- Coyotes and gray foxes in Texas and the southwest
- Foxes in Alaska
- Skunks in Kansas
- Bats (generally)
Pets allowed to roam in these regions are at highest risk of encountering a rabid animal and getting sick. Consequently, such high-risk pets place owners in danger as well.
How do puppies contract rabies?
Infection requires direct contact with an infected animal. The usual transmission is through a bite that introduces infective saliva into the wound. There, the virus proliferates until it reaches the nerves, which carry the infection to the spinal cord. Ultimately the virus reaches the brain, whereupon symptoms develop.
Puppies allowed outside risk wildlife encounters. Even puppies confined to yards or the house could be exposed to “high risk” wildlife, which includes the skunk, coyote, fox, raccoon, and bat. When sick, animals lose all fear and may wander into fenced yards, through pet doors, down chimneys, or attack litters of puppies or kittens.
Finding the dead animal where pets have access qualifies as exposure. Even when the skunk can’t be tested for the disease (too badly decomposed, or too damaged for brain analysis), the law requires it be treated as though rabid. That’s because pets can also be exposed by playing with the dead body or coming in contact with infective material.
Signs of Rabies
Rabies has three recognized stages of clinical disease: 1) incubation, 2) clinical signs, and 3) paralysis terminating in death. The incubation period -- the time from exposure (bite) to the development of symptoms -- takes 14 days to 24 months to incubate, with an average of three to eight weeks for most species. From the brain, the virus spreads to other tissues, like the salivary glands.
Clinical signs are mild to severe behavior changes. The first symptoms are a refusal to eat or drink, and the stricken dog typically seeks solitude. The disease then progresses to one of two forms; paralytic or dumb rabies, and furious rabies.
In the dumb form, dogs act depressed, become insensitive to pain, and develop paralysis of the throat and jaw muscles. It may look like they are choking or have something stuck in their throat as they salivate and drool. Pets with dumb rabies usually fall into a coma and die within three to ten days of initial signs.
Furious rabies is the classic presentation of mad dog symptoms. Dogs become extremely vicious and violent, and any noise prompts attack. Such dogs snap and bite at real or imaginary objects and may roam for miles attacking anything in their path. They lose all fear of natural enemies, and commonly chew or swallow inedible objects like stones or wood. Death occurs four to seven days after onset of clinical signs as a result of progressive paralysis.
The signs and course of rabies in people are similar to animals, and incubation ranges from two weeks to twelve months. There is no cure for rabies. Once signs appear, the mortality rate for the animal or person is virtually 100 percent.
Diagnosis of rabies can only be accomplished by microscopic examination of brain tissue from the suspect animal; this cannot be done while the animal is alive. Wild animals that act suspiciously, or attack humans or pets should be euthanized immediately, and the brain examined for evidence of rabies. Any pet that is bitten by an animal that cannot be tested for the disease should be considered exposed to rabies.
The Law and Rabies
Pets must be protected using a rabies vaccination by state law because they come in such close contact with people and may transmit the virus to humans after being infected by a rabid animal. Each state has established its own rules regarding rabies exposure in pets.
Animals are thought to be infectious only shortly before and during the time they show symptoms. Therefore, a biting animal capable of transmitting disease at the time of the bite will typically develop signs within a ten-day period. For that reason, ten days is the recommended period of quarantine in such cases.
The human risk is so high when handling suspect animals that it's safest that unvaccinated pets exposed to rabies be euthanized and then tested for the disease. Some local or state laws may allow an exposed pet to live under stringent quarantine for six months and, if no signs develop, be vaccinated prior to release. Recommendations for pets current on rabies vaccination that are exposed to the disease include immediate revaccination and strict owner control/observation for not less than 45 days.
Prevent exposure and protect your dog and yourself by restricting roaming. Keeping his rabies vaccination current also protects your puppy from the risk of being euthanized for testing, if he’s ever exposed. Any contact with wild animals acting in an abnormal behavior, including stray or feral cats or dogs, increases the risk.
The rabies virus is sensitive to many household detergents and soaps. Should you or your puppy suffer a bite, thoroughly wash the wounds with soap and hot water to kill as much virus as possible, and then consult a doctor and/or veterinarian immediately. The post-exposure vaccine available for people is virtually 100 percent effective when administered in the right period of time.