Trichomoniasis in Ducks: Oral Canker, Crop Lesions, and Liver Spread

Trichomoniasis is an infection caused by Trichomonas protozoa, most often Trichomonas gallinae in birds. It is best known for causing oral canker: yellow-white, cheese-like plaques and dead tissue in the mouth, throat, esophagus, or crop. In more severe cases, the infection can extend deeper and cause lesions in internal organs, especially the liver.

Although trichomoniasis is more common in pigeons, doves, and some raptors, birds in the order Anseriformes—which includes ducks—have also been reported with the disease. In domestic poultry and waterfowl settings, infection risk rises when ducks share water or feed with infected birds, especially pigeons and doves that may carry the parasite without looking sick.

This disease can move fast. Affected ducks may stop eating because swallowing hurts or because plaques physically block the esophagus. Young or weakened birds are at higher risk of rapid weight loss, dehydration, and death from starvation or airway obstruction. The infection is not considered zoonotic, so it is not known to infect people, but it still needs prompt veterinary attention for the duck and for flock management.

Trichomoniasis in ducks is caused by infection with Trichomonas parasites, most commonly T. gallinae. The organism lives in the upper digestive tract and nearby tissues. Different strains vary in how aggressive they are, so one flock may have mild disease while another has severe oral, crop, or liver lesions.

For ducks, the most likely source is contaminated water or feed. Shared waterers, ponds, bowls, and wet feeding areas can allow the parasite to move from bird to bird. Pigeons and doves are especially important because many are chronic carriers and may contaminate feed areas without showing clear illness.

Crowding, poor sanitation, and mixed-species housing all increase risk. Outdoor setups where wild birds can perch over feeders or drink from duck water sources are common trouble spots. The parasite does not survive well for long periods in dry conditions, but it can persist long enough in wet environments to spread efficiently.

In some birds, severe disease may involve extension from the mouth and esophagus into the crop and then deeper tissues. Liver lesions are reported more often in predatory birds that eat infected prey, but hepatic spread can also be part of advanced avian trichomoniasis and is one reason a duck with this disease needs a careful veterinary workup.

Your vet will usually start with a hands-on exam, body weight, hydration check, and a close look inside the mouth. The yellow-white plaques of trichomoniasis can be very suggestive, but they are not unique to this disease. Other problems, including candidiasis, poxvirus, capillaria, aspergillosis, salmonellosis, and vitamin A deficiency, can cause somewhat similar lesions.

To confirm the diagnosis, your vet may collect fresh material from the mouth or throat and examine it under the microscope as a saline wet mount to look for motile trichomonads. In some cases, culture or PCR testing is used, especially when the diagnosis is unclear, the bird has already been treated, or flock-level decisions depend on a more definite answer.

If your duck is very sick, your vet may also recommend additional testing such as cytology, bloodwork, imaging, or necropsy of a deceased flockmate. Those steps help assess dehydration, secondary infection, and whether lesions may have extended into the crop, surrounding tissues, or internal organs like the liver. Because birds can decline quickly, treatment discussions often begin while confirmatory testing is still in progress.

Prevention centers on water, feed, and wild-bird control. Ducks should have drinking water and feeding areas that are cleaned often and protected as much as possible from pigeons, doves, and other visiting birds. Shared, dirty, or stagnant water is a major risk factor. If you use bowls, troughs, or small tubs, empty and scrub them regularly rather than topping them off.

If trichomoniasis is suspected in your flock or in wild birds visiting your property, remove or restrict access to shared bird feeders and nonessential water stations for about 2 weeks, and disinfect surfaces with an appropriate cleaner such as a 10% bleach solution when safe for the material and after organic debris is removed. Let items dry fully before reuse.

Avoid mixed-species housing when possible, especially if ducks share space with pigeons, doves, or rescued wild birds. Quarantine new arrivals, watch for subtle signs like weight loss or swallowing trouble, and ask your vet about a flock plan if one bird becomes ill. Good sanitation will not prevent every case, but it meaningfully lowers exposure and helps protect the rest of the flock.