Sneezing and yellow lesions inside mouth

[Eggcessive]

I would also use the acidified copper sulfate as well as @azygous has recommended, even if you try the other treatments. Here is a rather long thread about canker from 2 years ago that you may be interested in reading:
https://www.backyardchickens.com/th...onidazole-for-small-canker-infection.1197165/

 

[ChickNanny13]

@Eggcessive Great thread, interesting and informative ... Thank you