Hello everyone. Im confused at to what is going on with my almost 13 year old Eskie. She is a sweet dog, always has been. This week she tried to warn me off by biting (not hard enough to break skin). She has never bitten before. She also has fleas, but has been bathed and had advantage applied. I cannot brush her, she sees the brush she tries to bite me. She has arthritis as well and is slowing down quite a bit. We went to the vet yesterday and she tried to bite two vet techs. She has always been good at the vet, and has never needed to be muzzled before. My vet put her on a pain medication, and said her back was arching when she did the physical. Im just worried because I don't know what is wrong with her. I want my sweet girl back.