Our first B very occasionally would shriek in pain and bite at her back legs/butt/tail area. This would be exclusively right after napping on the couch and then jumping down. Never when running intensely or jumping around when playing. It seems to have happened less over the last few months, maybe like once every other month…but not often enough for us to worry. She never seems to be in that much pain and it just doesn't happen often and increasingly less so.
But now our second B is having similar issues. Unfortunately it happens more often. Either after napping on the couch and jumping down or when first running after resting like when we first arrive at the dog park. But he shrieks much more loudly than our female ever did and seems to bite at his tail and butt much more frantically. In fact he'll fall over mid-run (from the pain?) and immediately go to the biting.
With the both of them it's only ever one quick shriek and a few moments of biting at the hindquarters. It doesn't seem to bother either of them for more than a few seconds...but what the heck is going on? We've palpitated all over their hindquarters trying to reproduce the pain but they have not responded at all.
Our vet said anal glands were suspect and he expressed them on our second B with the more occurrences of obvious pain. He didn't have any pain like that for a day but then it was back just like before. When he does the shriek and the biting and poops shortly thereafter (probably by coincidence cause sometimes he doesn't) while pooping he tries to look at his butt very intensely. When he drops the poop from his butt he'll turn around wicked fast like "what was happening back here!?" or "that hurt, what the heck!?" Stool is perfectly normal (and checked by vet/tests) and both dogs have clean bill of health from vet.
Any thoughts about this, anyone seen it before? Anal glands, muscle spasms/pain, tail issues (arthritis?)....