Parasites in Birds

By Gregory Rich, DVM; Laurie Hess, DVM; Rick Axelson, DVM

Parasites (either intestinal or external) are not commonly diagnosed in psittacines (parrot species). Galliformes (poultry) and Columbiformes (pigeons and doves), however, may harbour a variety of external and intestinal parasites. When present, parasites can cause generalized debilitation in birds and, in severe cases, some intestinal parasites can cause severe weight loss, anemia, and death. Some parasites are known to cause specific clinical conditions.

What exactly is a parasite?

Parasites are most commonly microscopic organisms that live on or in other living organisms, benefiting themselves but not the host organism. Internal parasites, which occur inside various organs of the body, such as the stomach or intestines, include worms (e.g., tapeworms, hookworms, and roundworms), protozoa (e.g., Giardia), and trichomonads. External parasites, infecting the skin or feathers, include mites, fleas, and lice.

Are certain species of birds prone to certain types of parasites?

Yes, some are prone to certain parasites. Some examples:

  • Canaries and Gouldian finches often develop infections with tracheal or air sac mites (Sternostoma tracheacolum), which cause severe respiratory problems. 
  • Cockatoos (especially those that go outdoors) may develop fatal respiratory disease from the parasite Sarcocystis
  • Cockatiels often develop Giardia infections of the intestinal tract that can cause diarrhea and severely itchy skin, which then may cause Feather Destructive Behavior.
  • Budgerigars (budgies) and canaries most commonly develop scaly, crusty lesions on the feet, beak, and/or face, caused by Knemidokoptes pilae mites (illustrated in photo at right). 
  • Intestinal parasites, such as capillaria, roundworms or strongyles, are more likely to be found in wild-caught birds, poultry, and pigeons.

(Photo credit: Gregory Rich, DVM)

How are parasite infections diagnosed?

Sometimes diagnosis is easy; other times, different diagnostic tests must be performed. With knemidokoptic mange (mite infection), your veterinarian can often make a diagnosis based on the results of a physical examination and a microscopic analysis of a skin scraping of the feet or beak. Diagnosis of intestinal parasites will require a microscopic examination of fresh fecal material. Blood parasites like malaria can only be detected by a microscopic analysis of a stained blood smear. Sarcocystis infections are diagnosed by serological analysis in live birds.

Are parasitic infections harmful?

Parasites are not usually fatal when diagnosed early, but they can cause discomfort (as in the case of skin parasites) or malnutrition (as in the case of intestinal parasites). Overwhelming parasitic infections in young or small birds can be serious, causing intestinal obstruction, severe anemia, and in some cases, death. At the very least, parasites irritate birds and make them unhealthy and prone to secondary infections.

How are parasitic infections treated?

External parasites are often treated with topical or oral antiparasitic medications. Additionally, the bird's environment, including its cage, perches, toys, and food and water bowls should be thoroughly washed and disinfected. If there are several birds in the same environment as the sick one, all birds may need to be treated to clear the whole flock or household of the parasites.

"If there are several birds in the same environment as the sick one, all birds may need to be treated to clear the whole flock or household of the parasites."

Internal parasites can be treated with a variety of oral or injectable medications. It is critical to follow your veterinarian’s directions, as oral or injectable anti-parasitic medications are dosed for each bird’s specific weight. Some medications may cause severe side effects if given improperly. Due to the life cycles of most parasites, several treatments may be needed. Annual veterinary examinations and fecal tests can help determine if your bird is infected with parasites.

My veterinarian recommends multiple fecal tests, yet they are always negative. Why are all these tests needed?

Keep in mind that a single negative fecal test may seem meaningless, as the test looks for parasite eggs in the stool, and the parasite may not be producing eggs at the time of the test. Multiple fecal tests are often necessary to diagnose parasites because some parasites shed eggs intermittently, and only adult stages are capable of reproducing. Fecal examinations are relatively inexpensive, and having one or two tests performed each year will help determine if your bird is harbouring intestinal parasites.

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