Hi Denis,
I am not sure if you are still checking responses and hope Achilles is feeling better now. But, when I read your comment, the first thing I thought of too (and agree with Aimee) is wondering if it could be a perianal fistula? My neighbor’s German Shepherd has that too and I think the condition is found more commonly in the breed. She has him on a canned grain-free, hypoallergenic diet called Natural Balance fish and potato. She mixes in some pumpkin because that helps keep things moving and makes it less painful. Using probiotics really helps too. I have used this brand Power Probiotic https://www.askariel.com/pet-probiotics-p/81.htm for many years with my pups. It’s easy to use and I have no idea why but my dogs will even lick it up without food! Anyhow, hope Achilles is doing better.
