Diseases From Animals: A Primer
A is for animals, Z is for zoonoses.
Diseases From Cats and Dogs continued...
Both cats and dogs sometimes get parasites that infect humans.
One of the most common is roundworm. Left untreated, nearly all puppies and
kittens pick up this parasite. Its egg-like form -- the oocyst -- can survive
for years in soil.
When humans ingest oocysts, tiny worms hatch in the gut and
move through the body. Symptoms include fever, coughing, asthma, and/or
pneumonia. Once in a while, the tiny worms enter the eye and scar the retina.
This results in permanent partial vision loss. "Some 750 to 1,500 kids go
blind each year with roundworm infection [of the eyes] passed from dogs through
feces to children, " Glickman says.
Other parasites of cats and dogs:
- Toxoplasmosis. See above.
- Tapeworm. A person gets infected by swallowing an infected flea -- a
relatively rare event, but it happens.
- Hookworm. Hookworms are common in tropical and subtropical areas. They
infest soil contaminated by animal feces. Humans get infected by direct
contact, usually by walking on contaminated soil. Heavy infections can be
- Cryptosporidiosis. This parasite cause mild to severe intestinal symptoms
like diarrhea. It's not usually a dangerous infection, except to people with
weakened immune systems.
Ringworm isn't a parasite, but a fungal infection that forms a
ring-shaped rash on the skin or a bald patch on the scalp. People can get it
from direct contact with an infected animal.
Cats and dogs get viruses, too. Rabies is the most dangerous
one. Be sure to keep up with your pet's rabies vaccination.
To protect yourself from diseases carried by house pets:
- Wash your hands with soap and running water after touching feces.
- Take your pet to the vet on a regular basis and keep up with all
vaccinations recommended for your area.
- Avoid rough play with cats.
- If your cat or dog bites you, wash the area with soap and water right
- Wash your hands after handling your pet -- especially before eating or
- People with weakened immune systems should take special precautions. These
include never letting pets lick them on the face or on an open cut or wound,
never touching animal feces, and never handling an animal that has
- Don't let your pet drink from toilet bowls or eat feces.