skip to main content

Public Health - Seattle & King County

Diseases from dogs

Dog

Animal bites: Dogs

In the U.S., dogs are responsible for more than two-thirds of domestic animal bites and cause approximately 19 deaths per year. Boys age 5 to 9 years are at the highest risk for injury. King County and state regulations require that animal bites to humans be reported to Public Health. Staff assess the risk of rabies and other infectious diseases and provide advice on medical management. Cats, dogs and ferrets that bite people are placed under rabies quarantine for 10 days; if the animal remains healthy during the quarantine it would not have been carrying rabies virus in its saliva at the time of the bite. Bites to people from wild animals may require administration of post-exposure rabies shots.


Rabies prevention

Rabies is one of the most feared diseases because it is virtually 100% fatal. It is caused by the rabies virus and is usually transmitted by the bite of a rabid animal. While human rabies is rare in the U.S., ranging from one to seven cases a year, rabies is a significant disease worldwide causing 55,000 deaths a year. India, China and Africa have the highest number of cases. Globally, nearly all human cases are contracted from a dog bite, while in the U.S. almost all cases are due to the bite of a rabid bat. In Europe, the U.S. and other developed countries, human rabies is controlled by vaccinating dogs and cats and by administering a series of post-exposure rabies shots to people exposed to a potentially rabid animal. King County regulations require that all dogs be vaccinated against rabies by 4 months of age and immunity maintained by booster vaccinations.


Brucellosis
Brucellosis is a bacterial infection that can affect goats and other livestock such as sheep and cows and wild ruminants such as deer, elk and bison. Brucellosis causes abortion or stillbirth in animals. Brucellosis is rare in livestock in the U.S. but common in many other countries. People most often get infected from direct contact with the placenta and other discharges from animals that are giving birth. Infected animals can shed the Brucella bacteria in milk and in vaginal fluids after abortion or birth. People can also get infected from consuming unpasteurized milk and other dairy products from infected animals. Symptoms in people vary, but serious disease can occur. Dogs can also get brucellosis but this type is rarely spreads to people.


Campylobacteriosis
Campylobacteriosis is an infection of the intestines caused by a bacterium called Campylobacter. The bacteria is commonly found in the feces of infected animals and in food products contaminated with the bacteria during processing or preparation. Raw or undercooked chicken is one of the most common sources of human infection.


Cryptosporidiosis
Cryptosporidiosis is caused by infection with a tiny parasite called Cryptosporidium parvum. The parasite produces cysts (eggs), which are passed in the stool of infected people or animals. The cysts can survive for 2 – 6 months in moist environments and are commonly found in lakes and streams. The parasite is spread by the fecal-oral route. People and animals can get infected when drinking contaminated water or eating contaminated food, or by direct contact with infected persons or animals. About 50% of dairy calves are infected and shed cysts. Infection can cause diarrhea and abdominal cramps. The disease is self-liming in healthy people, but can be prolonged and more serious in persons with weakened immune systems.


Dipylidium Infection (Dog and Cat Flea Tapeworm)
Dipylidium is tapeworm of cats and dogs. People become infected when they accidentally swallow a flea infected with tapeworm larvae; most reported cases involve children. Dipylidium infection is easily treated in humans and animals.


Leptospirosis

Leptospirosis in people: Leptospirosis is a disease caused by bacteria called Leptospira that infect both people and a wide range of animals. It occurs worldwide but is more common in temperate and tropical areas of the world. Some people infected with leptospirosis will have no symptoms at all, and some people will become severely ill. Some wild and domestic animals, such as cattle, pigs, dogs, raccoons, and rodents, carry the Leptospira bacteria and pass them in their urine. Soil or water contaminated with infected urine is the most common route of human infection.

In late 2004 King County began to see an increase in leptospirosis in dogs. Between 2004 and 2008, 110 confirmed or probable canine cases with 37 fatalities were reported to the King County Zoonotic Disease Program. A horse and one cat were also reported. Fortunately, no King County residents are known to have become infected during this outbreak. However, people could potentially get the infection from the same environmental sources as dogs (contaminated soil or water), and people in contact with an infected dog could get the disease through exposure to the dog's urine.


Ringworm
Ringworm is a skin disease that can affect people and many kinds of animals. It is not caused by a worm at all, but rather by fungus that can grow in the skin. Ringworm on a person's head usually shows as a bald patch of scaly skin and elsewhere it can cause a red, ring-shaped rash that may be itchy. Dogs and cats, especially kittens, can have ringworm and spread it to people by direct contact with the pet's fur. Spores of the ringworm fungus can survive for a long time on carpet, furniture and other surfaces and cause infections. People can also get ringworm from other people and their personal items like combs.

  • Ringworm (CFSPH, Iowa State University)

Salmonellosis
Salmonellosis is a bacterial infection of the intestines caused by a group of bacteria called Salmonella. The bacteria are shed in the stool of infected animals and humans. Infection can happen when a person eats food or drinks water or milk that has been contaminated with Salmonella bacteria. Infection with Salmonella can cause serious disease especially in children younger than 5 years of age and persons with weakened immune systems.


Toxocara infection (roundworm)

Toxocariasis is a disease affecting people caused by parasitic Toxocara roundworms commonly found in the intestine of dogs and cats. Although most people infected with Toxocara have no symptoms, the parasite is capable of causing blindness and other serious illness. It is likely that toxocariasis is under-diagnosed. A recent study showed that transmission of Toxocara is most common in young children and youth and that about 14% of the U.S. population is infected. Children become infected as they tend to play in (and sometimes eat) soil or sand that has been contaminated with dog or cat feces.