Unfortunately the most common cause for first time seizures in an older dog are brain tumors. Other causes are trauma to the head, and ingestion of a neurotoxin. Idiopathic seizures occur in dogs that are less than 3-4 years of age. I think that Adequan or Rimadyl are unlikely causes since neither is a neurotoxin.
Brain tumors can cause change in personality, panting and pacing. Not all brain tumors are death sentences, though. Some are benign and surgery can be successful.
Thank you, Dr. Cheng. The results are in and it is a brain tumor. The vets tell me that it is inoperable though radiation is an option but that even that will not cure her. Very sad news. I appreciate your answer.
I'm so sorry for you both. You have obviously loved your dog for every one of these 11 years. Try to remain focused on all of those good years instead of the end. You've given her a fabulous life and I'm sure you'll ease her through the end when the time is right. The end isn't what is important - it's everything else that came before.
I am so sorry to hear this news. I'm just so sorry.
Thanks for the kind notes. I am happy to report that for now she is much improved on phenobarbital and prednisone. And I am focusing on loving her for as long as I can.