Giardiasis

By Tamara Sevigny

Your pup has diarrhea, is lethargic, and has lost weight... The symptoms are characteristic of more than a few diseases. But if your pup has had contact with filthy (or potentially contaminated) water, or with other dogs showing similar signs, Giardiasis should at least be suspected.

What is Giardiasis?

Giardia are tiny, one-celled parasitic organisms that are likely to cause serious illness. Giardiasis can cause dogs to get extremely sick and need treatment, while others can be carriers and show no symptoms at all..
Giardia matures in stages, similar to that of many other disease organisms. However, unlike many others, no time elapses between infestation with the dormant phase, and establishment of the disease. Once cysts are ingested by the dog, they open and release the mobile form of the organism, known as the trophozoite. The trophozoites then make their way to the intestine. In a healthy dog the trophozoites may live in the lower digestive tract for years. If the dog has an undeveloped or overburdened immune system, the trophozoites continue to divide and multiply, causing this debilitating disease.
Giardia can infect several species, including humans. Therefore the presence of cysts in the environment can cause an outbreak in people as well as other pets. Furthermore cysts can remain viable for many weeks or even months in cold, wet environments, so areas littered with feces should be avoided and cleaned up.

Symptoms

- Soft, light-colored and greasy diarrhea, either acute, intermittent, or chronic.
- Lethargy
- Vomiting
- Excessive gas
- Usually the infected animals will not lose their appetite, but they may lose weight.

Diagnosis

Since diarrhea is a common symptom of intestinal infection, causes such as Salmonella and Campylobacter are generally ruled out before testing for Giardia is done. Direct microscopic inspection of feces is necessary to determine the presence of the protozoan. Examination of soft feces may reveal the active trophozoites, and cysts may be found in firm excrement. The number of cysts can vary from day to day, so best chances of detecting Giardia lies in collecting samples over three days for a fecal flotation test, or conducting individual tests every two or three days until at least three tests have been done. A quicker test does exist, but it is more expensive and requires an experienced technician to run.

Treatment

Depending on the severity of the disease there are a couple of options of treatment, some with two- or three-day protocols and others needing seven-to-10 days to complete the cycle.
Flagyl (Metronidazole) is a treatment for bacterial infestations that cause diarrhea and is about 60-70 percent effective. However, Flagyl has potentially serious side-effects in some animals, including vomiting, liver toxicity, anorexia, and some neurological signs, and it cannot be used in pregnant dogs.
Panacur (Fenbendazole), generally used in treating roundworm, hookworm, and whipworm, has been shown to be effective in treating canine Giardiasis. Panacur is safe to use in puppies at least six weeks of age.
When traveling or going on walks with pets, owners should prevent them from drinking dirty water. However, if you or your pets have come in contact, or have been diagnosed with Giardia, all areas that you and your pets inhabit, including outdoor and kennel areas, should be cleaned thoroughly. Lysol, ammonia, and bleach are effective decontamination agents.
Because Giardia crosses species and can infect people and other pets, sanitation is important when caring for dogs.  Always be sure to wash hands after cleaning dog runs or removing feces from yards.