My dog doesn’t stop licking his butt
Hello, I have a problem with my 11 year old dog (he is a poodle mix). He is pretty healthy in general for his age and active but since 1-2 months he started having issues. First with his anal glands which the vet extracted. The anal glands were really full and a little bit sore. After the extraction he went basically back to normal but then he started licking his butt. We dewormed him (which we always do like every 2-3 months). But the licking continued so we thought his anal glands were maybe full again but they weren’t. The vet tried to extract them but told us they were empty. She then gave him Cortisone which didn’t really help. I don’t know if he became allergic to anything food related but he just licks his butt and occasionally his paw (not excessively just a nibble) he shows no other signs (no diarrhea, farting, vomiting). I don’t really know what I can do next. I went to the vet again yesterday and she said she doesn’t know what his problem is. His butthole is a little bit darker than usual (the vet explained it could be hyperpigmentation due to the excessive licking). Please help me idk what to do anymore. He oftentimes licks in the middle of the day or at night time or really early in the day. It mostly is really suddenly. Some background info: his deworming medication also works against flees and ticks. We switched a while back his kibble because he needs special renal kibble (his renal function got worse and the vet said it would be better to switch to this specific kibble type).