Diseases to Worry About with a Stray Cat

FIV, the feline equivalent of HIV, and FeLV are both immunodeficiency diseases: they damage the immune system of the infected cat, making it difficult for him to fight off diseases. Feline leukemia, though not a cancer itself, is so named because it also increases a cat's risk of developing certain cancers, including leukemia. Both diseases are ultimately fatal, though affected cats may remain symptom-free for some time. Humans are not affected by these diseases, but obviously any other cats you have will be at risk if you bring an infected stray into your home. It's critical to have a vet give a new cat the OK before introducing him to your little pride.

Toxoplasmosis is contagious to humans, and is a particular concern for pregnant women and those with a compromised immune system. It's an infection from the parasite Toxoplasma gondii, which is found in cat feces. For most people this illness is no big deal, and in fact there's a good chance you've already contracted it without knowing it—many healthy people show no symptoms. Those who do usually get headaches, fever, sore throat, muscle pain and enlarged lymph nodes, though people with compromised immune systems may have more serious symptoms. Treatment isn't usually necessary, but when given consists of antibiotics and antimalarial drugs.

Bartonellosis is also known as cat scratch fever or cat scratch disease. Although most people are acquainted with the term "cat scratch fever" as it refers to humans, cats can also infect other felines with this disease. One cat can infect another through licking, sneezing, spitting or biting in addition to scratching. Symptoms of bartonellosis infection in cats include a high fever, conjunctivitis, pneumonia, swollen lymph nodes and bronchitis. Symptoms of the disease in humans include fatigue and fever, similar to having a cold or mild case of the flu, headache, swollen lymph nodes and the development of pimple-like bumps on the scratch site. While medical treatment is typically not needed, people or cats with compromised immune systems may be given antibiotics.

Ringworm is a fungal infection that can be transmitted from cat to cat, as well as from an infected cat to dogs and humans. Symptoms of ringworm include circular spots of patchy hair loss, because it's not actually a worm—it's a fungus. It isn't necessary for the cat to have close contact with others to spread ringworm. The disease can be transmitted through contact with infected food dishes or bedding. Ringworm spores can remain active for up to one year, making this a difficult disease to eradicate once it's established.

Rabies is a common concern with strays because of the nearly 100 percent fatality rate. Areas that have large wild animal or feral animal populations are more likely to harbor animals with the rabies virus. Rabies is most often transmitted through the bite of an infected animal, but any exposure to the saliva of an infected animal can lead to transmission. Don't approach any animal that appears hostile or disoriented, or is otherwise acting strangely, but also remember that an animal may be rabid for some time before it starts showing symptoms—meaning that any bite is cause to make an appointment with your doctor. All that said, don't panic: with prompt attention after a bite, rabies is totally preventable with just a few shots in the arm.