Rabies in Dogs: How to Protect Your Pet and Prevent This Fatal Disease

Westend61 / Getty

Discussing the signs and symptoms of rabies in dogs is an inherently tragic topic. That's because once the signs of rabies infection appear, it's already too late. There is no treatment or cure, and the disease is fatal. However, there is good news. Rabies is also preventable through vaccination.

How Do Dogs Get Rabies?

Rabies is a viral disease that affects the central nervous system, causing deadly inflammation in the brain and spinal cord. The virus can infect any mammal—including humans. According to the Centers for Disease Control and Prevention (CDC), most pets get rabies from interacting with wildlife. In the U.S., raccoons, bats, skunks, and foxes are the most common disease carriers.

The rabies virus is present in the saliva of infectious animals, and transmission typically occurs when a dog is bitten by one of these animals. Though rare, the virus can also be transmitted when infectious saliva comes into direct contact with a scratch or open wound or with a mucous membrane (e.g. eyes, nose, mouth). The CDC notes that contact with the blood, urine, or feces of an infectious animal is not a cause for concern.

Once the rabies virus enters a dog's body, it travels through the nerves to the brain. This process, known as the incubation period, typically takes anywhere from two weeks to around five months, says Brandi Whittemore, DVM, of Hancock Veterinary Services in Pineville, Mo., though it can be longer or shorter. Dogs don't show any clinical signs during the incubation period. These typically begin once the virus reaches the brain and begins multiplying. And once signs appear, the disease is fatal. It's also at this point that the virus moves into the salivary glands, producing infectious saliva.

Signs and Symptoms of Rabies in Dogs

The first sign of disease is often a sharp, sudden change in personality, says Whittemore. For example, a friendly, outgoing dog may become shy and withdrawn or vice versa, and a gentle dog may become aggressive. According to the Merck Veterinary Manual, other behavioral changes include loss of appetite, apprehension or nervousness, irritability, and hyperexcitability.

As the disease progresses, Whittemore explains that the signs typically fall into one of two categories: furious or dumb. With the furious form, the pet may bite, exhibit aggression, eat abnormal items, and experience difficulty eating and drinking. Merck adds that dogs with this form of rabies will often have dilated pupils and look alert and anxious. They may also lose their fear of other animals and experience seizures and loss of muscle coordination. Pets with the dumb (also called paralytic) form of rabies appear to be in a stupor, says Whittemore.

According to Merck, this form is often marked by paralysis of the throat and jaw muscles. These dogs tend to have problems swallowing, a drooping lower jaw, and excess drool. They are also less likely to be aggressive and rarely bite.

Sadly, Whittemore says that both forms eventually result in paralysis, coma, and death.

Diagnosis and Treatment of Rabies in Dogs

Diagnosing rabies is difficult. Because the disease shares signs with other illnesses, you can't tell a dog has rabies just by looking at them. The only way to definitively confirm the virus is to examine the animal's brain tissue in a laboratory, says Whittemore. This means that the only way to diagnose rabies is after the dog has died.

Once a dog starts displaying the signs of rabies, there is no treatment and the disease is fatal.

How to Prevent Rabies in Dogs

Rabies can't be cured, but it can be prevented. And because rabies is both the deadliest infectious disease and zoological (meaning it can be transferred to humans), prevention isn't left to chance. Whittemore says that in most states, you're legally required to vaccinate your dog between 12 and 16 weeks of age, with a booster shot a year later. You can find out what's required in your area by visiting with your veterinarian or by contacting your local health department. Local laws also determine how often your dog needs a vaccine booster shot. It may be required once a year or once every three years.

The CDC estimates that around 60 to 70 rabid dogs are reported in the U.S. each year and that almost all of them had never been vaccinated. So while no vaccine is 100 percent effective, the rabies vaccine is highly successful at preventing infection.

Vaccination is the safest and easiest way to prevent infection, but there are other steps you can take as well. Because most pets are infected by wild animals, you can help lessen your dog's odds of coming in contact with the virus by keeping them indoors and on a leash when outdoors. The CDC also recommends calling animal control if you see a stray animal in your neighborhood as it may not be up to date on their shots. Taking these steps will not only protect your pet, but you and your family as well.

What To Do if Your Dog Comes in Contact With a Potentially Rabid Animal

If you think your dog has been exposed to rabies, you should immediately take your pet to your veterinarian. What happens next depends on the dog's vaccination status.

If your dog is up to date on his vaccines or has been vaccinated before but is overdue on his booster shot, he will be revaccinated. You will be asked to closely watch your dog for signs of illness for the next 45 days.

If your dog has never been vaccinated before, the CDC recommends immediate euthanization. The other option is to vaccinate your dog and place him in strict quarantine where he can't have direct contact with people or animals for four months.

Regardless of vaccination status, any dog under observation or in quarantine who develops signs consistent with rabies infection should sadly be euthanized and then tested for the disease.