Chicken Trichomoniasis: Canker, Mouth Lesions, and Upper Digestive Infection

Chicken trichomoniasis is a contagious infection of the upper digestive tract caused by Trichomonas gallinae, a microscopic protozoan parasite. In birds, this disease is often called canker. It most commonly affects the mouth, throat, crop, and esophagus, where it can trigger inflammation and thick, caseous plaques that look yellow, white, or cheesy.

Although trichomoniasis is more common in pigeons and doves, chickens can develop serious disease, especially when they share water sources with wild birds. In chickens, the infection can move quickly. Affected birds may stop eating well, lose weight, drool, or struggle to swallow because the lesions physically block food and water from passing normally.

This is not a condition to diagnose at home. Mouth lesions in chickens can also happen with pox, trauma, vitamin A deficiency, fungal disease, chemical irritation, or other infections. Your vet can help sort out the cause and decide what level of care fits your flock and your goals.

Chicken trichomoniasis is caused by infection with Trichomonas gallinae. The parasite lives in the upper digestive tract of infected birds. Pigeons and doves are important carriers, and chickens may be exposed when they share contaminated water, feed areas, or outdoor spaces with these birds.

For chickens, contaminated water is a major source of infection. The parasite can survive for hours in water, so dirty waterers, birdbaths, puddles, and shared outdoor drinkers can spread disease. In backyard settings, risk goes up when wild birds can perch over feeders or drink from the same containers as the flock.

Not every exposed chicken becomes severely ill. Disease severity can vary with the strain of parasite, the bird's age and immune status, and how much tissue damage develops. Because other mouth diseases can look similar, visible plaques alone do not confirm trichomoniasis.

Your vet usually starts with a careful oral exam and flock history. They will want to know when signs started, whether wild pigeons or doves visit the coop, whether birds share outdoor water sources, and whether any flock mates have died or shown similar lesions.

A common next step is testing a fresh swab from the mouth or throat. Trichomonads are often identified by examining the sample promptly under a microscope because the organisms lose motility as the sample ages. In some cases, your vet may recommend culture or additional lab work if the diagnosis is unclear.

Diagnosis also means ruling out look-alike problems. Wet pox, trauma, fungal plaques, vitamin A deficiency, and bacterial infections can all cause oral lesions. If a bird dies, a diagnostic lab necropsy can be very helpful for confirming the cause and checking for other flock health concerns.

Prevention focuses on water hygiene and wild bird control. Clean waterers often, scrub off organic debris, and refill with fresh water daily or more often in warm weather. Do not let chickens drink from stagnant puddles, dirty birdbaths, or shared outdoor containers that pigeons and doves can access.

Try to reduce contact with wild birds around the coop. Keep feed covered, place food and water indoors or under shelter when possible, and discourage pigeons and doves from roosting above chicken areas. Good general biosecurity also matters: quarantine new birds, avoid sharing equipment between flocks without cleaning it, and watch closely for any bird that starts eating poorly or develops oral lesions.

If one chicken develops suspicious mouth plaques, separate that bird and contact your vet. Fast action can improve the affected bird's comfort and may reduce exposure risk for the rest of the flock.