How Much Do You Know About Pet Diseases?

Zoonoses are diseases of animals that can be transmitted to people. There are many zoonoses, and many different animals can carry a wide variety of diseases. Hypochondriasis is a mental condition that results in imagined diseases rather than actual illness. Toxicosis is an illness or toxic condition caused by chemicals or drugs. Narcosis is a sleepy or comatose state caused by an overdose of a narcotic such as heroin, morphine, or codeine. Halitosis means bad breath.

Cats can carry more than 60 diseases that can be transmitted to humans, including cat-scratch diseases, toxocariasis, and ringworm. Dogs carry many fewer. Birds can carry diseases such as psittacosis, which can cause pneumonia. In the United States, however, it is extremely rare for pet birds to be infected with disease that humans can catch. Tropical and saltwater fish carry very few diseases that humans can catch.

Although toxoplasmosis is normally a benign disease in adults with a normally functioning immune system, it can cause devastating disease in the fetus. Ninety percent of infants born with congenital toxoplasmosis will have neurological damage or psychomotor retardation. They may also have blindness, hydrocephalus, seizures, anemia, and other problems.

Although rare, cutaneous (skin) anthrax is diagnosed most frequently in sheep shearers. The shearers are infected by spores of the bacteria Bacillus anthracis, which are trapped in the wool. The spores enter the skin through tiny cuts or abrasions. An itchy sore can develop at the site; the lesion then usually blisters and forms a black sore. If untreated, cutaneous anthrax can be fatal.

Despite its name, ringworm is not caused by a parasite. It is a fungal infection that causes irritation to the scalp or skin, making skin reddened or scaling. This type of ringworm (passed on from animals) makes up only about 10 percent of ringworm cases. The rest are caused by a fungus that's passed from one child to another child through contaminated combs, brushes, hats, hair accessories, pillows, and bath towels. For either type of ringworm, the treatment is a skin cream or oral medication that kills the fungus.

Dogs are legally required to be vaccinated against rabies, and most dog owners are compliant. Cats, however, usually aren't vaccinated. Wild animals seldom get vaccinated. Recently, it has become possible to vaccinate coyotes with food laced with the vaccine. This is being done in Texas to reduce the incidence of rabies among coyotes.

It has been estimated that pet turtles alone account for up to 20 percent of all salmonella infections. Poultry frequently harbors salmonella. Dogs and cats are much less likely to carry salmonella, although it is possible.

Children get head lice from other children, not from animals. Animals do carry animal lice and mites, some of which can temporarily infect humans, but head lice are specific to humans. Effective treatment shampoos and egg removers are available over the counter and should be used exactly as directed.

Hantavirus was first discovered in the desert Southwest, when it caused unexplained deaths from pulmonary failure. The Centers for Disease Control and Prevention (CDC) determined that mice in the area carried a virus called hantavirus. The virus is present in their urine, which dries and mixes with dust. The virus can become airborne when a homeowner does "spring cleaning," disturbing the dust containing the virus. The dust and virus are inhaled, causing a severe type of pneumonia and lung failure.

This condition is caused by intestinal hookworms shed by dogs and cats in their feces. The larvae of these worms burrow into the skin and produce a wandering trail just beneath the skin. Most cases of hookworm caused by dogs or cats are found in the Southeastern United States, along the Gulf Coast. According to the CDC, children who play in contaminated soil are at risk for developing hookworm, as are electricians, plumbers, and others who must crawl beneath raised buildings where the hookworm larvae may be found.