Rabies

by Bruce W. Little, DVM


Monday September 28 is World Rabies Day. Created in 2007 by the Global Alliance for Rabies Control, World Rabies Day is meant to bring attention to the fact that approximately 70,000 people worldwide die from rabies each year according to the Centers for Disease Control and Prevention (CDC). Greater than 99% of these deaths occur in Africa and Asia with almost one-third of the deaths in India alone. Some sixty percent of deaths due to rabies are children under age 15 who were bitten by a dog. It is rare for a human being to die from rabies in the United States of America, although in any certain year one or two deaths can occur. This huge disparity between developed countries and poor, third-world countries is primarily due to laws and regulations by municipal governments that force dog and cat owners, and in some areas other pet animals, to be vaccinated with highly successful rabies vaccines. Also, in developed countries, early intervention in the form of wound management and post-exposure prophylaxis has a high success rate in preventing rabies infection in humans post-exposure to a rabid animal. Rabies, once it reaches the central nervous system in the body and exhibits clinical signs, is 99.9% fatal, but it is also 100% preventable. Eliminating the disease by vaccinating dogs, cats and ferrets protects the pets and stops transmission to people.

Rabies may be the first recognized infectious disease, as well as the first zoonotic disease meaning it can be transmitted from animals to man, in recorded history. There are references to rabies in the annals of history dating back to Mesopotamia and Babylon in the 23rd Century BC. Reference has been made to laws in Mesopotamia that fines a man “15 shekels if his dog bites another man and makes him mad.” The legal codes of Babylon described the penalties for owners of dogs who bite humans. Rabies is a contagious disease in animals that is typically transmitted to pets through contact with wild animals. The virus is secreted through saliva and is usually transmitted to people and other animals by a bite from an infected animal. There are thousands of mammalian species that are susceptible to rabies, however, only a few of these species are considered to be major reservoir hosts for the disease. The most frequently reported rabid wildlife species are raccoons, skunks, foxes, coyotes and bats; however, positive tests have been found in other species, such as, groundhogs, opossums, white-tailed deer, beavers and other land mammals. Fish, amphibians, reptiles and birds are not susceptible to rabies.

In the United States, most cases of human rabies results from being bitten by a bat. There are numerous strains or variants of the rabies virus amongst bats in different parts of the country. The U.S. Geological Survey National Wildlife Health Center has determined that one in ten bats submitted to a qualified laboratory for testing has been positive for rabies. If you live in an area that harbors a significant bat population, you should positively keep the rabies vaccinations for your dogs, cats and ferrets current. You might also need to bat-proof your house so the bats cannot gain access to the house while the family is sleeping. Unvaccinated dogs and cats continue to be the major sources of rabies transfer to humans in America. In any endemic area of the country, those ratios can be skewed depending upon the enforcement of rabies vaccination laws and compliance with vaccination procedures. According to the World Health Organization (WHO), rabies is widely distributed across the world and is found on all continents except Antarctica.

It wasn’t until the 1940’s and 1950’s that municipal governments in the United States and most of North America began dictating laws that pet dogs and cats must be vaccinated for rabies. In most areas today, ferrets are included in that requirement for vaccination for rabies. From the 1960’s forward the incidence of rabies in the United States has diminished appreciably. There will be outbreaks of variant strains of rabies virus in wild animals and bats that pose a threat to unvaccinated pets; and therefore, increased risk for family members of those pets through contact with an unvaccinated dog or cat. The incidence of rabies in cats is more prevalent in the U. S. than dogs because cats are less likely to be vaccinated for rabies and are more likely to roam outside unsupervised. For some reason, cat owners seem reluctant to take their cats to veterinarians for vaccinations for several preventable diseases. In any area where a certain strain of rabies variant breaks out in the wildlife population, including bats, the incidence in pet cats and feral cats rises accordingly. These cats need to be vaccinated! Rabies also occurs in significant numbers in cattle and, while it is not as common, has been diagnosed in horses, goats, sheep and swine.

Dogs, cats and ferrets with rabies may show a variety of clinical signs including restlessness, confusion, fearfulness, aggression, self-mutilation, excessive drooling, difficulty swallowing, staggering and seizures. They may become aggressive and bite when they normally are very docile. Veterinarians and other animal caretakers must be extremely careful when handling animals that exhibit the signs and symptoms of rabies. Besides being bitten by the rabid animal as a means of transmission of the virus to humans, it can also be transmitted when the saliva of the infected animal comes in contact with open wounds on the hands and face or through the mucous membranes of the eye, nose and mouth. The virus is excreted in the saliva in infected animals during clinical illness and for only a few days prior to illness or death. Rabid cats are more likely to exhibit aggressive behavior, where dogs are inclined to show lethargy and paralysis. Bats can transmit the virus by bite as early as 12 days before showing clinical signs and 24 days before the bat’s death. Since the teeth on bats are very small in size, it may be difficult to find a bite from a bat. Rabies is not transmitted through contact with blood, urine or feces of an infected animal.

Once the virus has reached the central nervous system of the bitten or exposed animal, including humans, treatment is very unlikely to be successful. It has been determined that 99.9% of those infections that reach the central nervous system are fatal. If a person is bitten by an animal, either wild or domestic, you should wash the area of the bite thoroughly with soap and warm water. Then urge the victim to see a physician immediately and to follow the physician’s recommendations. Check with your veterinarian or the veterinarian that services the dog or cat that done the biting and see if it has a current rabies vaccination. Report the bite to the local health department and animal control authorities. If your pet is a cat, dog or ferret, the officials will confine the animal and watch it closely for ten days. If the rabies vaccination for the biting animal is current, the health officials may allow home confinement in some municipal jurisdictions. The animal must be available for observation by a veterinarian or a public health official at the end of the quarantine period. After the recommended observation period, have your pet vaccinated for rabies if its vaccination is not current.

Rabies control in any area of the world is a community project. Rabies can and will proliferate in the wild animal, stray dog, feral cat and bat populations. However, rabies can be controlled almost completely with proper protocols in place and adhered to. Have your veterinarian vaccinate your dogs, cats, and ferrets and horses and cattle if in an endemic area and it is advised by your veterinarian or other health professionals to do so. Your veterinarian will advise you on the recommended or required frequency of vaccination in your area. Reduce the possibility of exposure to rabies by not letting your pets roam free. Keep cats and ferrets indoors, and supervise dogs when they are outside unless they are in a secure fenced area. Do not leave exposed garbage or pet food outside as it may attract wild or stray animals. Teach children to never approach or handle wild or unfamiliar animals, even if they appear friendly. Wild animals should never be kept as pets.

The public health problem posed by rabies should be addressed with a massive, global rabies vaccination campaign, according to experts writing in the journal Science. “There is now convincing evidence that vaccination of dogs would eliminate greater than 98 percent of the rabies health burden globally” said veterinarian Dr. Guy Palmer, director of Washington State University’s Paul G. Allen School for Global Animal Health. As a member of Rotary International, I was privileged to be a part of the control and extinction of Poliomyelitis throughout the world in 1992. Through the efforts of Rotary International polio vaccine was purchased and distributed to all corners of the world and volunteer doctors, nurses, nurse technicians and other health professionals responded to the call to donate their time to go to underprivileged areas of the world to administer those vaccines. Rotary accomplished this feat three years before the targeted date of 1995. I believe with the proper organization of groups like the Global Alliance for Rabies Control and the help of compassionate people the world over we can wipe out rabies in the same fashion as we wiped out polio. It will take a concentrated effort by many and a lot of luck by all, but it can be done! I will do my part, will you?


Global Alliance for Rabies Control
American Veterinary Medical Association
Centers for Disease Control and Prevention



Bruce W. Little, DVM