Blister on dog’s paw?

My dog has just starting licking and chewing at his front paw and when I looked at it I saw this. It looks like a blister of some kind? Please can you help me to know what this is/ how it might’ve occurred and what I should do to try to offer some relief to him? He was limping a bit when he walked on it just now- it seems to have appeared all of a sudden (or, at least, neither he nor I have been aware of it until now, it seems!). Thank you so much for your help.🙏🙏🙏

Hello!  I think that this could be a corn.  They sometimes come about due to poor weight bearing on the pad, which can often be secondary to lameness or arthritis.  It can be worse if repetitive use of hard surfaces is involved and sometimes changes in walking / exercise habits, treatment for the underlying condition and padding out the foot may be suggested.  There are definitely other possibilities and other treatments so we reccommend showing this one to your vet.  If they're unsure, they may decide to biopsy for example.  Please do let us know how you get on.