Most diseases are species-specific and don't jump from one species to the other. Since dogs and cats are both domestic pets that frequently live together, it's important to know what diseases they can share. The illnesses they do share can be easily treated with keen observation and early intervention.
The most common problem owners of both cats and dogs have is the transmission of worms. The larvae of intestinal worms -- such as hookworms, roundworms, tapeworms and whipworms -- is found in feces. If your dog and cat have access to the same areas in which to eliminate, your cat can step in microscopic eggs and later lick them off her paws.
If one of your pets has a tapeworm, a flea can eat a tapeworm egg, then land on the other pet, who ingests the flea, transmitting the tapeworm from one to the other.
As gross as it sounds, some dogs will sample the "leavings" in your cat's litter box. If your cat has roundworms, your dog could potentially ingest roundworm eggs.
Whipworms and hookworms are also shared through contact with each other's feces, though they rarely infect cats.
Ringworm is not a worm, but dermatophytes, a fungus. Before it was discovered to be a fungus, medical professionals thought the loss of hair was due to a microscopic worm on the skin, thus the misnomer. Ringworm is instantly recognizable by its circular shape. It could appear as a hot spot, but on canines it forms a perfect circle so is seldom mistaken for one. In cats, ringworm is atypical in that it could have an irregular shape. Ringworm is spread from one pet to the other through direct contact. The spores can also live on bedding, carpeting and grooming tools and can be spread through contact with these items as well. Dermatophytes also live quite well for months in soil, if the conditions are right, and dogs and cats can contract it from contact with the infected dirt.
The Common Cold
Dogs and cats can suffer from the common cold just as people can. Commonly called "kennel cough," bordetella bronchisceptica is a nasty bacteria that causes dogs to become very sick with flu-like symptoms. The bacteria can be spread to cats living in the same household or kennel with an infected dog. The symptoms are the same in both cats and dogs: fever, lethargy, discharge from nose and eyes, coughing and sneezing. Since that list of symptoms is also representative of feline upper respiratory infection, it can be tough for the vet to determine which pathogen is responsible for the pet's illness. The presence of a dog with kennel cough, or having just recovered from kennel cough, is an important clue. There is an intranasal vaccine for both cats and dogs to protect them from bordetella.
Rabies can infect just about any mammal. If your cat is bitten by a rabid wild animal, and then bites a dog, the dog could also be infected with rabies, and vice versa. The animal does not necessarily have to be bitten by a rabid animal -- just coming into contact with the saliva of a rabid animal could be enough to transmit the disease if the contact is through an open wound or mucosa. Fortunately, there is a vaccine against rabies and laws in all 50 states to ensure all pets are vaccinated against this deadly disease.
- The spitz-dog and cat on a neutral background image by Ulf from Fotolia.com