Does anyone have experience with canker?

[Sunflower]

I have a 6 year old plymouth barred rock hen who I believe has canker. This old girl is still pretty peppy, eats good, she is the top hen. But she has a swollen eye, excessive thirst, shakes her head a lot and has the brown things in her mouth. I have not heard good things about this canker and I can't believe my favorite hen has it.
She has an old injury from jumping off her perch and she limps, breathes heavy with her mouth open just about 90% of the time. She has had heat stroke twice in the last 4 years.
I talked to my vet and she didn't have a lot of experience with this illness but doesn't think the outcome is good. I just need some honest answers from anyone that has lost a chicken to this or who has heard about anyone that has had to deal with it. Since it can spread through the flock, I'm thinking the best thing for everyone is to cull. I don't want to at all, she is my favorite, she is such a sweetie.
Any input would be appreciated! Thank you

 

[dawg53]

Canker can be treated with metronidazole 250mg, once a day for 5 days. It can be purchased online as Fishzole. Canker is contageous and infected birds remain carriers. It can be kept in check by adding 1/4 teaspoon acidifed copper sulfate per 1 gallon of water once a month for 3 days straight.
https://www.mcmurrayhatchery.com/acidified_copper_sulfate.html
http://pet-healthcare.revivalanimal.com/search?w=fishzole

 

[Sunflower]

Thanks Dawg! Do you have an experience w/ chickens that have had this? I'm just wondering what to expect down the road. It appears that two may have this already, so I'm postponing culling her, I think I'm too late in keeping it from spreading. I only have 7 chickens now. Thanks again