-- Giardiasis is caused by a protozoan of the giardia species.. Giardia are one-celled organisms that live in
the small intestines of dogs and cats. Dogs get the
infection from drinking water from streams or other sources
contaminated with infective oocysts, and an infected dog can pass
it on to other dogs. Though an infection with Giardia is not
intitially fatal to your dog's health, it can develop into a very serious
condition. Some dogs are carriers who show no symptoms,
but others get sick and need treatment. Since the Giardia
organisms interfere with the normal absorption of your dog's food, this
can result in malnutrition, weight loss, and other serious symptoms. The feces are often
abnormal, being pale, having a bad odor, and appearing greasy. In the
intestine, Giardia prevents proper absorption of nutrients,
damages the delicate intestinal lining, and interferes with digestion. Clinical
signs range from none in asymptomatic carriers, to mild recurring
diarrhea consisting of soft, light-colored stools, to acute explosive
diarrhea in severe cases. Due to the frequent diarrhea that most dogs
experience when infected with Giardia, a dog may also become severely
dehydrated. Young dogs can develop
diarrhea that may be acute or chronic, intermittent or persistent,
and may be accompanied by weight loss,
listlessness, mucus in the stool, and poor appetite. These signs are
also associated with other diseases of the intestinal tract, and are not
specific to giardiasis; therefore positive identification of these
organisms is an important aspect of a thorough patient work up.
Diagnosis is made by finding the protozoan in saline smears of fresh stool.
Treatment: Giardiasis responds well to Flagyl. Flagyl should not be administered to pregnant bitches, because it causes developmental malformation in the fetus.
There is no evidence that cysts shed by dogs cause human infection. Contaminated water sources are the principal source of giardiasis in people. Experts don't agree on how many species of Giardia there are and which ones affect which animals.
Giardia is the most common parasite in humans residing in North Americia
Giardia can also cause diarrhea in humans. Therefore,
environmental disinfection is important. The use of chlorine
bleach, one cup in a gallon of water, is effective if the surfaces and
premises can be safely treated with it.