Rabies (this can be spread to people)
Canine parvovirus infection ("parvo")
Canine enteric coronavirus
Bordetellosis ("kennel cough")
Intestinal worms (roundworms, hookworms, whipworms, tapeworms, etc., some of which can also infect people)
Rabies is a deadly disease caused by a virus that attacks the nervous system. The virus is secreted in saliva and is usually transmitted to people and animals by a bite from an infected animal. Less commonly, rabies can be transmitted when saliva from a rabid animal comes in contact with an open cut on the skin or the eyes, nose, or mouth of a person or animal. Once the outward signs of the disease appear, rabies is nearly always fatal.
Canine parvovirus is a highly contagious virus that can affect all dogs, but unvaccinated dogs and puppies younger than four months old are the most at risk. Dogs that are ill from canine parvovirus infection are often said to have "parvo." The virus affects dogs' gastrointestinal tracts and is spread by direct dog-to-dog contact and contact with contaminated feces (stool), environments, or people. The virus can also contaminate kennel surfaces, food and water bowls, collars and leashes, and the hands and clothing of people who handle infected dogs. It is resistant to heat, cold, humidity, and drying, and can survive in the environment for long periods of time. Even trace amounts of feces from an infected dog may harbor the virus and infect other dogs that come into the infected environment. The virus is readily transmitted from place to place on the hair or feet of dogs or via contaminated cages, shoes, or other objects.
Canine distemper is a contagious and serious disease caused by a virus that attacks the respiratory, gastrointestinal and nervous systems of puppies and dogs.
The virus can also be found in wildlife such as foxes, wolves, coyotes, raccoons, skunks, mink and ferrets and has been reported in lions, tigers, leopards and other wild cats as well as seals.
Leptospirosis is a disease caused by infection with Leptospira bacteria. These bacteria can be found worldwide in soil and water. There are many strains of Leptospira bacteria that can cause disease. Leptospirosis is a zoonotic disease, which means it can be spread from animals to people. Infection in people can cause flu-like symptoms and can cause liver or kidney disease. In the United States, most cases of human leptospirosis result from recreational activities involving water. Infection resulting from contact with an infected pet is much less common, but it is possible.
Leptospirosis is more common in areas with warm climates and high annual rainfall but it can occur anywhere.