Canker is caused by a flagellate protozoan and is also known as trichomoniasis, roup or frounce. It is not transmittable to humans or other mammals, but can be caught by other birds that share the same water, eat seed dropped by an afflicted bird, or through direct beak-to-beak contact. The organism Trichomonas gallinae lives in the sinuses, mouth, throat, oesophagus and other organs. This disease occurs worldwide in warm climates or during warm weather.
Finches are reported frequently, but potentially any bird can be infected, in particular pigeons, doves and birds of prey. Birds of prey are thought to get infected by eating infected prey. Scavenging can also infect corvids, in particular birds, who are already immunocompromised due to other health problems.
Canker causes plaque like lesions in the throat of the infected bird, which makes it progressively harder for the bird to swallow and eventually to breathe. The affected bird will eventually starve to death, suffocate or suffer a fatal bleed. Birds will also show signs of lethargy and fluffed up plumage, drooling saliva and regurgitated food. Infected saliva is known to contaminate a birdbath. This is what you can do to help:
- Use feeders with drainage holes to avoid moisture building up
- Use more than one feeding site and rotate feeders to reduce the number of birds in one place and to prevent build up of infection on the ground underneath
- Clean and disinfect feeders and water baths regularly, rinsing them thoroughly and allow to air dry completely
- Sweep up droppings, spoiled or old food and dispose of it carefully in a covered outside bin
- Change the water in baths and drinkers frequently
- You may want to consider the use of commercial water sanitisers like Vetark Citrosan Water Sanitiser or natural organic apple cider vinegar
Apple cider vinegar destroys microorganisms, including bacteria, fungi, viruses and others. It has been proven to inhibit the growth of gram-negative bacilli, Pseudomonas and Candida. The acid nature of vinegar makes the digestive tract environment generally unpleasant for germs and fungi. Apple cider vinegar will acidify the contents in the crop and intestinal tract and will discourage the multiplication of Trichomonas organisms. It will, however, not cure canker.
To keep algae growth down and your bird bath clean, add 5 ml natural organic apple cider vinegar (containing about 4 to 7 percent acetic acid) to 1 liter of drinking water. Natural apple cider vinegar also provides vitamins and minerals to the birds.
If you find a bird suffering of canker, and are able to catch him or her, then please bring the bird to an experienced wildlife rescue, as this disease is curable when detected early enough. Please do not try to remove any visible canker plaques, as this will most likely cause a fatal bleed.