WHAT IS CANKER?
Trichomoniasis, also called “canker” or “roup” (in raptors, “frounce”), is usually characterized in all birds by the presence of whitish and/or yellowish cheese-like material in the throat and mouth. This material can also be present in the crop, lungs, sinuses and nares (nostrils), and can cause lesions on the liver. In severe cases, the accumulation of material can be so great that the affected area can rupture. Some common signs of canker are insatiable hunger and/or thirst, weight loss, general ill appearance, panting or open-mouth breathing and lethargy; however, this does not mean that a bird which appears healthy does not carry the organism which causes canker.
This disease is HIGHLY contagious, and it is not species-specific; this means that ANY bird can get or give the disease from or to ANY bird, wild or domestic. There is no vaccination available at this time, and successful recovery from an infection of Trichomonas gallinae does not necessarily prevent future infections. However, it is possible that some immunity can be gained if chicks are exposed to small amounts of the organism over a period of time, beginning at hatching.
HOW IS IT CONTRACTED?
The most common source of T. gallinae is stagnant water. Infected birds drink from a common water source, and this spreads the infection to innumerable individuals. Birds of prey may contract canker by consuming infected animals, and chicks of pigeons and doves can contract the infection from the parent birds’ crop milk. Domestic pigeons and wild doves have historically shown the greatest number of infections, although this does not rule out any single group of birds, wild or domestic, from becoming epidemic.
A simple way to significantly reduce the possibility of contaminated water is to use only flowing and/or circulating water sources. Another benefit to circulating water is the prevention of mosquito larvae hatching; mosquitoes can transmit West Nile Virus to birds and other animals, including humans, and the disease can be fatal. It should be noted that while the circulation of water keeps the number of organisms down, the container should still be disinfected regularly.
NOTE: West Nile Virus is NOT “bird flu”. These two diseases are caused by completely different organisms, under different circumstances. It is important to remember that bird flu is prevalent mostly in countries where humans live among poultry in crowded, unsanitary conditions.
HOW IS IT TREATED?
Because the organism which causes canker is a protozoan, antiprotozoal medications are used to treat the infection. There are several available, including: dimetridazole; metronidazole; ronidazole; aminonitrothiazole; nithiazide (as a preventative measure) and carnidazole (brand name Spartrix). ONLY SPARTRIX IS APPROVED BY THE US FDA!
Canker can be treated on an individual or group basis; with mass treatment, usually the medication is put in the water source. Of course, this means that not all birds will get the same dose, as different birds drink different amounts of water, and some may never drink from a treated source; however, many feel that some treatment is better than no treatment.
With individual treatment, the bird is quarantined and usually given oral medication until the canker is resolved, which can be a lengthy process involving daily removal of accumulation of canker material and disinfection of the cage, perches and dishes the infected bird comes into contact with.
HOW DO I KNOW IF A BIRD HAS CANKER?
If you think that your bird may be ill, the best course of action is always to have a veterinarian examine the animal and run appropriate tests. Some signs that a bird may be ill include, but are not limited to: lethargy; loss of appetite; weight loss; feather problems; and skin problems.
In many cases, birds with canker will seem insatiably hungry, because they are not able to swallow much food, if any. You might see a bird gasping, or panting, because it cannot get enough air. Another potential sign is a greatly enlarged throat area, where the crop would be, not associated with mating display or territory-claiming “puffing”.
If you are able to safely catch the bird, you can look into the mouth and throat to see if there are any lesions on the mucus membranes, or if the “gunk” is present. Remember to thoroughly wash your hands and any bare skin that touched the bird before handling any other animal or touching any other exposed skin on yourself. While T. gallinae is an avian disease, there are other strains of Trichomonas which CAN infect humans.
Once again, the only way to know for sure that a bird has canker is to have the animal examined by a veterinarian familiar with avian diseases!
Information sources on the Internet:
(a Canadian racing pigeon site, but canker is canker!)
FDA dosage validation for Spartrix, a medication for the treatment of Trichomoniasis
FDA Center for Veterinary Medicine
Database of Approved Animal Drug Products (DAAD)
Fallen Feathers, Inc. (this is the rescue & rehabilitation group of which I am the co-founder, Assistant Director, and volunteer)
Arizona Game and Fish