Birds are susceptible to parasites just as mammals and reptiles are. For most mammalian parasites there is a counterpart in the bird world. Birds can be infested with internal parasites such as worms, and with external parasites like mites. Birds that are kept outdoors or in flocks are more likely to have a problem with parasites because of their increased risk of exposure. One or two birds caged together should have minimal risk of becoming infested with parasites assuming they were parasite-free when purchased. Some of the more common types of parasites are described below.
Nematodes, also called roundworms, can be found in nearly any body system of the bird. They are most commonly associated with the intestinal tract. The infestation occurs when the bird ingests the eggs which have contaminated the food, water, toys, or soil. The eggs then hatch, the larvae develop into adults, and the adults then produce more eggs which are passed from the body in the feces and contaminate the environment. Another bird, or the same one, can then ingest the eggs and the cycle begins again. Birds with a heavy infestation typically show signs such as unthriftiness, poor growth, or diarrhea. Some types of nematodes invade the respiratory tract causing breathing difficulties.
Diagnosis is made by seeing the worms in the feces, or more commonly, by an examination of fecal material under the microscope. Treatment is with fenbendazole, ivermectin, or pyrantel pamoate, and is typically repeated in 14 days. Always consult with your veterinarian regarding treatment using any of these medications. Some of them should not be used in certain species, for example, fenbendazole should not be used in some of the smaller birds such as canaries and cockatiels. Prevention includes cleaning cages daily including all items that have fecal material on them such as food/water dishes and toys.
Trematodes and cestodes (flukes and tapeworms)
Caged companion birds should have very little risk of exposure to flukes and tapeworms. These parasites have an indirect life cycle that requires an intermediate host such as a snail or earthworm. The intermediate host eats the parasite egg and then, in turn, the bird eats the intermediate host infesting itself with the parasite. Treatment is with praziquantel or epsiprantel. Removing fecal material daily and preventing the bird from ingesting intermediate hosts should help prevent the bird from getting trematodes and cestodes.
Protozoan parasites are a diverse group that include coccidia, Giardia, and cryptosporidia. The first two can cause blood-tinged feces and diarrhea. The diagnosis is made by examining a very fresh fecal sample. Birds infected with coccidia are usually treated with Amprolium, and those with Giardia infections are treated with metronidazole. Cryptosporidia affects the cells of the respiratory and intestinal tracts causing symptoms such as severe diarrhea, nasal discharge, sinusitis, and coughing. An effective treatment is currently not available. Again, reducing fecal contamination is necessary to prevent infection with the protozoans.
Arthropod parasites of birds include mites, lice, and ticks. The infestations can occur on the skin or feathers, although a few may infest the respiratory tract. Some of these parasites have their entire life cycle on the bird while others live part of their life in the environment. Symptoms include feather chewing, feather loss, poor feather quality, and skin inflammation. The parasites can sometimes be seen on the bird with the naked eye. Treatment depends on which arthropod is found.
This is a short list of the many parasites that could be a problem in birds. The common points in prevention include obtaining the bird from a reputable breeder, quarantining the bird before exposing it to other birds, routinely performing fecal examinations, providing proper sanitation, and treating the bird, if needed. If your bird has any symptoms of external or internal parasites, have it examined by a veterinarian. A proper diagnosis by a veterinarian will eliminate needless treatments that may be harmful to the bird.