GuideTreat canker
Target GroupCorvids

NOTE: In all my guides, I start from a situation where a rehabilitator takes his responsibility to take care of the animals in an ethically correct way. You should always try to minimize stress for the bird and since the birds, just like humans, are not the same, it can mean that you handle a problem in different ways by being creative! If I see different ways of doing the same thing, I try to write it down in my guides, but it is always up to the rehabilitator to take their own responsibility.
I do not have to write “I recommend putting the bird down” or “contact a veterinarian” or “according to law, you should …” because I start from the situation where you do the best for the bird and that you as a rehabilitator have learned to draw the line so that you do not end up in an unwanted or illegal situation. There may be an eternal battle between what you want and what is best for the bird.
There are also many factors where a similar situation can give different results. For example: access to a veterinarian, lack of time, lack of knowledge and previous experience can include cause large differences in the treatment and decision-making process and indirectly also the end result. Knowledge of basic things can make a huge difference in the stress level of the crow. For example. avoid anything that is black or checkered. They do not like it instinctively and it creates stress when they see that you are dealing with something that is black.
I put energy into my guides to make it easier for a rehabilitator to find information and to spread knowledge.
Do you see a way to improve my guides or do you see a mistake or do you want to add something, feel free to inform me!
If you are worried about doing something because it is new, ask other rehabilitators or a veterinarian for help.
The guides are continuously updated, so make sure to always download the latest version from

This guide describes what to do with birds that have been given yellow buds (Trichomonas gallinae)


Birds get the disease called “canker” by a parasite called Trichomonas gallinae. Most often, small birds die from this parasite. Fortunately, crows are a little better at surviving an attack of the parasite.
Most often, birds get the parasite by drinking from contaminated birdbaths, so it is important to clean the birdbath daily. Canker usually also is a seconday disease. This means the bird has something else, and because of that, the immunity is low and canker has a chance to spread.
It can be coccidiosis, but it can basically be anything that has disrupted the immune system. For example. an infection.

Chance of survival

Crows have a good chance of surviving the disease. It is smaller species such as finches (including the bullfinch) that have difficulty surviving the disease. It’s not just genetic bad luck. With a large “plug” in the throat you can not eat and if a bird can not eat, it dies quite immediately. The reason is that they have to eat quite a lot to survive a cold winter night.
A larger crow has more room to let its food (and air!) Pass by the coating.

What does it look like in crows?


First and foremost. Do not try to peel off the coating! Then it can start to bleed and it will probably end badly.

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What to start right away:

Add apple cider vinegar (no other vinegar !) in the drinking water of the bird you take care of. (5ml per 1liter of water)
Apple cider vinegar destroys microorganisms, including bacteria, fungi and viruses. It has been shown to inhibit the growth of gram-negative bacilli, Pseudomonas and Candida. The acidic nature of vinegar makes the environment in the digestive system inhospitable to bacteria and fungi. Apple cider vinegar acidifies the environment in the intestinal tract and complicates the proliferation of Trichomonas organisms. However, it will probably not cure canker.
In any case, apple cider vinegar is a good addition when a bird has low resistance.


There are various medicines on the market to cure canker

Link to a store that delivers to EU countries:
Should a bird have both canker and coccidiosis, there is Harkers 3-in-1 (NOTE: Difficult to obtain within the EU, even if it is produced in the Netherlands!) or cocci-tricho-tablets (from Holland!). Check out Amazon if you live in the UK!

One might wonder why there are only pigeons on all packaging? The reason is that the medicine is approved for pigeons. Abroad, there are many who have pigeons as a hobby. Show pigeons are sometimes worth SEK 1,000,000 each (or even more). So those who have expensive, special pigeons are very afraid that they will get sick and so medicine came on the market. Supply and demand!

Unfortunately, there are not many who want to catch wild sick animals to make sure they get well again. It’s all about the money!

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