Zoonotic illnesses are conditions that people can acquire from animals. From house cats in particular, a parasite was discovered by researchers as a possible cause of schizophrenia.

For a study published in the journal Schizophrenia Bulletin, E. Fuller Torrey and Robert H. Yolken analyzed data gathered from two earlier studies possibly linking cat ownership during childhood with risks of developing schizophrenia during adulthood. One of the studies the researchers used pointed out that individuals infected with a parasite called Toxoplasma gondii were twice as likely to develop schizophrenia.

T. gondii is normally found in cat feces. It grows infectious between one to five days, eventually releasing spores to spread out and find a host. Aside from directly catching the spores from touching cat litter, people may also be exposed to the parasite after eating wild game and other animals that may have ingested the spores.

A T. gondii infection often doesn't show symptoms so early detection is difficult. However, the U.S. Centers for Disease Control and Prevention estimates that over 60 million people in the country are potential carriers of the parasite.

Unfortunately, the T. gondii is not the only threat people have to face from their beloved pets.

Out of all diseases that pets can pass on to their owners, ringworm is one of the most contagious, although it can easily be treated with prescription oral or ointment medication for pets and their humans. In pets, it would appear as hair loss patches with red centers and skin lesions, while a ringworm infection looks like red, circular patches on the skin for humans.

Another reason to be careful around pet feces is salmonella. The bacteria is most commonly acquired by eating contaminated food but turtles, snakes, lizards and birds can also carry it, spreading salmonella through their feces. An infection results in fever, diarrhea and stomach pains.

Lyme disease, on the other hand, can't be transmitted to people directly by pets. However, ticks from cats or dogs can carry Lyme disease-causing bacteria. Avril Lavigne was diagnosed with the condition last year, forcing her to be bedridden for five months. Without treatment, Lyme disease can develop into a chronic condition that causes pain and heart and nerve inflammations.

There are different ways by which pets can get their humans sick but infections and diseases can easily be avoided by practicing good hygiene. Keep pet areas clean and make hand-washing a habit after handling pets to keep parasites, bacteria, viruses and the like at bay.

Photo: Jamie Lantzy | Flickr