I have a 10 year old white English lab that has the same issues that you are stating. Mostly on his front paws but sometimes on his back ones. We have been dealing with this issue for about 5 years, at least 5 different vets and an out of town dermatologist. His medicine was running about $300 a month until recently we tried a shot that is roughly $180 foot I believe 4-6 weeks, didn’t help. Some of the medicine he was taking was making him hallucinate. I am at a loss as of what to do.