Giardia in Dogs

Giardia is a protozoan parasite found all over the world. It infects humans, many domestic animals and birds. Giardia lives in the intestinal tract and infection may be asymptomatic or can result in gastrointestinal symptoms.

Giardia infections (called Giardiasis) show no gender or breed predilection but are most common in young animals and in animals under close confinement, such as those in kennels, animal shelters and pet stores.

Most cases of Giardia infection in humans arise from person-to-person contact or from contaminated water, but animals do harbor strains of Giardia that are infectious to humans and animal-to-human transmission theoretically is possible.

What to Watch For

Diarrhea

Vomiting

Weight loss

Flatulence (excessive gas)

Diagnosis

Veterinary care should include diagnostic tests and subsequent recommendations. Diagnostic tests are needed to recognize Giardiasis and exclude other diseases. Tests may include:

Direct fecal smears to look for two different stages of the Giardia organism called “cysts” or “trophozoites.” A positive direct smear results in a conclusive diagnosis of Giardiasis, but direct fecal smears may be negative in infected animals.

A zinc sulfate concentration test to identify Giardia cysts.

An enzyme-linked immunosorbent assay (ELISA) test to identify Giardia antigens in the stool.

Direct immunofluoresence test to identify Giardia cysts in feces.

Collection of samples from the duodenum (first part of the small intestine) during endoscopy and examination for Giardia trophozoites.

Treatment

Treatment for pets with Giardia infection may include one or more of the following drugs:

Metronidazole

Fenbendazole

A combination of praziquantel, pyrantel and febantel

Home Care and Prevention

Administer as directed all medications prescribed by your veterinarian. All of the prescribed medication should be given to insure elimination of the infection. A high-fiber diet may improve stool consistency in pets with diarrhea associated with Giardia infection.

Decontamination of the environment is an important part of preventing infection. In multiple-dog households and in situations in which animals are under close confinement (e.g. kennels, animal shelters, pet stores), proper sanitation is crucial to prevent cross-contamination from one animal to another. All fecal material must be removed from cages, runs and yards. Kennels must be cleaned with appropriate disinfectants and totally dried before allowing pets access to them.

All animals should be treated with appropriate medication before being introduced into a multiple-animal environment.

Bathing animals before introducing them into an uncontaminated environment allows for removal of feces and infective cysts from the hair coat.

Pet owners should remove feces from the yard, avoid allowing their dog to drink from streams and lakes, and regularly bath the animal to remove any feces from the hair coat.

A vaccine designed to aid in the prevention of disease caused by Giardia recently has been developed (GiardiaVax®).