What is giardia?
Giardia is a parasite that lives in the intestinal tract of numerous species. It is a protozoan -- a type of motile parasite -- and appears most prevalent in cockatiels. Birds and other animals become infected by ingesting the cysts of giardia, usually by means of contaminated water, but also directly by ingestion of feces containing the cysts. Giardia can survive for a substantial amount of time in the environment, so infection can occur simply by placing a bird in a contaminated cage or aviary. No one is certain as to why cockatiels are over-represented with this disease, but some believe there may be a genetic predisposition or immune deficiency, making this species poorly able to fight off infection on their own.
What are giardia's symptoms of infection?
Cockatiels with giardiasis are often asymptomatic. They carry the parasite but do not seemed harmed by the infection. The parasite may be detected during routine examination of an otherwise healthy bird. Those showing symptoms can exhibit signs of poor weight gain, shabby feathering, feather plucking, itchiness, or watery droppings. The most common presentation at our practice is a bird with watery droppings and ripping feathers out as if they were painful.
How is giardia diagnosed?
Infections with giardia often go undiagnosed, as it is an extremely difficult parasite to detect. A fresh (examined within 5-10 minutes) dropping can be checked under a microscope and examined for the characteristic movement and appearance of adult giardia, or the less easily recognized cyst form. Droppings may also be sent to a laboratory where a trichrome stain technique can be used to detect it. Both methods are unreliable, however, because they depend on the affected bird shedding giardia at the time of examination. More often than not, birds are not shedding the organisms in the droppings, so negative results are common. Currently, research is being done to develop a blood test to detect antibodies to giardia.
What if my bird is affected?
Treatment for giardia infection is difficult. The most common treatment is with metronidazole. Our experience with this drug has shown rapid improvement in the bird's condition, but frequent relapses once the medication has been discontinued. recently we have been using a more holistic treatment recommended by Dr. Greg Harrison of Lake Worth, Florida. This involves oral dosing of a combination of lactulose and Echinacea, and administration of apple cider vinegar in the drinking water. There has been remarkable success with this procedure, but it is not a 100% cure. During and after treatment, proper disinfecting is important, as birds can easily reinfect themselves by ingestion of contaminated feces. The cage floor must be changed frequently to prevent access to droppings. Use of a grate is advisable. Disinfecting with a 1:10 dilution of bleach in warm water will aid in killing the parasite. If well water is the primary water source, owners may want to consider testing for this parasite, or simply boil the water to kill giardia cysts.
What else do I need to know?
Giardia in cockatiels is usually asymptomatic or causes relatively mild symptoms. Rarely do we see a bird become ill as a result of this parasite. Take your bird for an annual well-bird checkup and have your veterinarian check its fresh droppings. Frequent monitoring is your best bet for early diagnosis and treatment of giardia.