[Jindo]

My dog has been snapping at his tail aggressively while barking and yelping. He will lie down for a while, seemingly comfortable, then he will suddenly spring up and start snapping like something has just hurt him. We've given him flea medicine for a couple weeks now and he continues doing it. We've also tried Trazodone in case it was something like anxiety and there's no difference.
The worst part is that he has actually bitten us multiple times because of it. He always rolls over to let us pet him and when we do he usually lies down comfortably. However, he will randomly spring up and bite us now as if he didn't realize we were there or like we startled him even though we've been petting him for a couple minutes already. When he bites he goes into this frenzy where he won't let go after a few seconds even though we are telling him to stop and obviously in pain. This hasn't happened before and he use to let us pet him for hours on end without any negative reaction.

We are at a loss for what to do and frankly scared to pet him now. We take him on walks frequently and there doesn't seem to be any other issues. We think that there might be something wrong mentally but the medicine hasn't done anything.

 

[FinnAlva]

Are you working with a vet regarding this problem? The dog might be ill somehow.

 

[SusanLynn]

Your dog's tail may be injured or infected. I would definitely start with a vet examination. I would rule out physical causes before considering a mental one. It sounds like your dog is in pain.