ASK THE VET (Trichomonas)

In a previous column, I wrote about the protozoan parasite, giardia. Today's column is about another protozoan parasite, trichomonas gallinae. This parasite causes the disease trichomoniasis.

It can infect pigeons, doves, turkeys, chickens, quail, hawks, eagles, falcons, canaries, 'keets, parrots, sparrows, swallows, goldfinches and cardinals. The protozoan exists in a trophozoite stage only. It moves by means of hair-like structures known as flagella.

Baby pigeons or squabs become infected when they ingest trophozoites in pigeon milk produced in the crop. Pigeons may also become infected by ingesting contaminated food or water. In pigeons, the disease is often called canker. Raptors may become infected by eating infected birds. In raptors, the disease is often called frounce. Other types of birds may become infected by ingesting the parasite in contaminated water. Nestlings of many species may become infected with an umbilical form which occurs when trophozoites pass from an infected nestbox through the navel.

The parasite lives in the mouth, esophagus, crop and tracheae, but may also spread to other organs. Trichomonas may cause white plaques and inflammation in the oral cavity. An infected bird may have a loss of appetite, vomiting, ruffled feathers, diarrhea, dysphagia (difficulty in swallowing), dyspnea (difficulty in breathing), weight loss, and increased thirst. Young birds are most frequently infected and can die from the parasite. Some birds may be carriers and show no sign of the disease. Diagnosis of trichomonas may not be easy. The disease may resemble pox virus, candidiasis, or vitamin A difficiency. The parasite may be found in a direct saline smear of oral fluids, and in scrapings taken from the crop or from oral lesions. Organisms may also be cultured.

Antiprotozoal medications can be used to treat trichomonas. Birds should be provided with a clean, dry, uncontaminated environment. Water should be fresh and overcrowding should be avoided.