Abstract
Giardia intestinalis is a small protozoal parasite that affects not only birds, but also man, monkeys, dogs, cats, horses, reptiles and many other species. It has been reported from many species of birds, of which the budgerigars and cockatiels seem to be the pet birds most commonly affected. There are numerous reports of giardiasis causing numerous deaths in commercial aviaries and individual pet birds.
There are no characteristic signs of giardiasis. The signs may consist of diarrhea or soft feces which are sometimes light yellow and occasionally brown, loss of weight, lethargy, unthrifty birds and death. Giardiasis may also be asymptomatic, that is showing no signs. In one article in the Journal of the American Veterinary Association a case was reported where the adults appeared healthy and the only signs were the death of 70-100% of the nestlings between the ages of 10 - 28 days. The nestlings became gradually weaker, did not feather properly and eventually the parents stopped feeding them. Their toes were covered with dried fecal material, probably a result of diarrhea. Treatment with antibiotics was useless in stemming the number of deaths.
In cockatiels the disease seems to be more chronic with a lower mortality (death) rate. Often the cockatiels are thin and eating well and sometimes there may be poor feathering with or without itching. One author has claimed that the feathers are characteristically "greasy looking'.'
It appears that infection rates increase when birds are confined together and stressed, and decrease when the birds are caged alone or kept in small numbers. Giardiasis should be suspected when:
1) A bird has a history of being an "illdoer" - that is, never seems to be quite right, has poor feathering, loose stools, etc.
2) A history of diarrhea that does not respond to treatment with antibiotics. 3) Unexplained itching and poor feathering.
4) High nestling mortality.
Giardia can be diagnosed by examining the feces for the protozoal parasite under a microscope. The treatment consists of good sanitation and quarantin-
ing and testing all new birds. Affected birds are treated with a drug called Dimetridazole (Emtryl - Salsbury Lab). It is a powder and one teaspoon should be mixed with a gallon of water for five days, wait five days and treat again for five days. For birds that do not drink much water, it may be necessary to have your veterinarian give it by a gauge tube three times at 12 hour intervals.
Is giardia transmissible to people from their birds? According to an article in the journal of the American Veterinary, the exact incidence is not known, but it is known that man can acquire it from other animals and viceversa and, in fact, the researchers in this article developed giardiasis that persisted for several weeks. Their conclusion was that if the overall prevalence of giardiasis is as high as their data suggests and if it is transmissible to man, then such transmissions may...