Roblin Animal Hospital
Unit 104-4910 Roblin (corner of Roblin and Dieppe)

Monday - Friday 8am - 6pm
Saturday - 8:30am - 12:30pm

Roblin Animal Hospital/ Red River Spay and Neuter :


What is Giardia?


Giardia Basics

Giardia is a single celled organism, known as a protozoan that can wreak havoc of your pet’s small intestines. Giardia is transmitted through unfiltered or untreated water. If your pet ingests this protozoan s/he will become very sick. Once in your pet’s system, it will attach to the wall of your pet’s small intestines. It will then cause damage to the villi (the nutrient absorbing finger-like projections) which enable it to do its very important job. This results in the immediate passing of food which will appear as severe diarrhea. If you notice that along with excess mucus production, frothy stools, a rancid odor, depression, and weight loss (if the problem goes unchecked for long enough) in your pet, take him/her to the vet immediately. Giardia has been known to kill younger puppies within a matter of days. To prevent possible infection in your pet, make sure s/he doesn’t drink untreated water (pond water, lake water, puddles, etc.) whenever the both of you are out. Always bring water for your pet in case s/he gets thirsty.

Giardia Life Cycle

Trophozoite (adult form of giardia) eggs (oocysts) are passed out in the feces of an infected animal. At this point, the cyst is in a non-infective stage where it can live in the environment for a fair amount of time (2 weeks-1 month in water). This is because its outer layer is a protective barrier against heat, cold, and infection from other organisms.  When another animal accidently ingests giardia, by fecal-oral transmission, or by drinking infected water, the cyst “hatches” and releases the adult trophozoite within. The trophozoite will then divide asexually to create copies of it. At this point, the adults will attach to the wall lining of the small intestine of their host and feed on it. This damages the villi, causing the host to have severe diarrhea (along with the other symptoms mentioned before). The trophozoites then reproduce sexually with one another to produce the oocyst which will be passed through the feces.

Giardia Treatment

There are a few drugs that can be given to your pet if s/he contracts giardia. One of them is called Flagyl which has a drug called Metronidazole in it. Metronidazole is an antibiotic that destroys the giardia parasites. It has been found however, that this method of treatment may not be as effective as another. The other treatment for giardia in dogs and ruminants (four stomach chambered animals) is a drug called Albendazole. Albendazole works very well in dogs and ruminants, but may cause side effects such as lethargy, lack of appetite, and slower production of white blood cells. Another drug called Fenbendazole is the recommended drug for the treatment of cats.

Public Health Significance

Giardia is known to be zoonotic, meaning that it can be easily transferred to humans who come in contact with animals infected with giardia. It is best for humans to take proper safety precautions when handling an animal with the sickness. Always wash your hands after handling the animal and keep your hands and any objects away from your mouth that have come into contact with the animal. Also, avoid drinking untreated water from lakes, ponds, and streams. If you suspect you have contracted giardia, go see your doctor as soon as possible.

By Jackie Elias