Rabies is a fatal viral infection that kills an estimated 35,000 to 50,000 people and millions of animals around the world each year.

North Dakota State University Extension Service veterinarian Charlie Stoltenow is urging people to prevent themselves and their animals from becoming infected.

The most common way to get rabies is from a bite of an animal with the disease. Infection through fresh wounds or mucous membranes is less likely but possible, Stoltenow says.

Thirty-two cases of rabies in animals were reported in North Dakota in 2006. Of these, 17 were skunks. Skunks are a primary rabies carrier in North Dakota, but any mammal can get the disease.

Here are some prevention tips:

• Make sure dogs, cats, ferrets and horses have current rabies vaccinations.
• Avoid contact with skunks or raccoons seen during the daytime in unusual locations.
• Pet owners and livestock owners should not perform oral exams on animals that appear to have difficulty chewing or swallowing, exhibit any type of oral or facial paralysis or show excessive salivation. Veterinarians should use extreme caution when doing oral exams on such animals.
• Contact local animal control authorities about animals you suspect may have rabies.

Behavioral changes and unexplained paralysis are two indications of rabies. Other warning signs are anorexia, apprehension, nervousness, irritability, hyperactivity, isolation, lack of coordination, altered vocalization, changes in temperament and uncharacteristic aggressiveness.

Rabies exists in two forms: furious and dumb. Animals with the furious type are irrational and will attack other animals, people or moving objects at the slightest provocation or noise. They assume an alert position and expression with dilated pupils and may chew or swallow foreign objects. Lack of muscular coordination, paralysis and death follow.

Symptoms of dumb rabies include paralysis of the throat and jaw muscles, profuse salivation and difficulty swallowing. Animals may drop their jaws. Death eventually follows.

However, the rabies virus may be in saliva for three to five days in domestic dogs and cats and up to eight days in skunks before the animals show clinical signs that they have the disease, according to Stoltenow. Also, signs of the disease generally take 14 to 90 days to show up in the victim of a rabid animal bite, although research shows the disease’s incubation period can be as short as nine days and as long as seven years.

“The variability is due to a variety of factors, such as the location of the wound, severity of the wound, distance from the brain, and amount and strain of the virus introduced,” he says.

The virus stays at the bite site for a considerable amount of time. It replicates in muscle cells and travels along nerves to the spinal cord and brain, and then to the salivary glands.

Initial human symptoms include apprehension, excitability, headache, fever, malaise and sensory changes at the bite site. As the disease progresses, victims suffer from paralysis, difficulty swallowing, delirium and convulsions. Eventually they go into a coma and die, usually from respiratory failure.

People who suspect they’ve been exposed to rabies should contact their doctor immediately, Stoltenow says. A rabies postexposure prophylaxis series is available for people who have been exposed to the disease, but the cost can exceed $3,000 per person.

Agriculture Communication