Giardia are protozoa (one-celled organisms) that live in the small intestine of dogs and cats. Giardia are found throughout the United States and in many other parts of the world. Giardia prevents proper absorption of nutrients, damages the delicate intestinal lining, and interferes with digestion.
Giardia is passed through the feces of an infected animal and can contaminate the environment and water. Giardia can live several weeks to months outside the host in wet, cold environments (lawns, parks, kennels, etc...).
The usual sign of Giardia infection is diarrhea. The diarrhea may be acute, intermittent, or chronic. The infected animal may lose weight.
Giardia can be transmitted to and cause disease in humans.