First of all, I have been to the vet multiple times with the issue in my dog and she is stumped as to what it could be. Second, sorry for the wall of text that is about to happen.
My sister's dog is the topic today. She's probably around 6-7 years old, a blue heeler mix, about 45-50 pounds, neurotic, and has severe anxiety issues. She's terrified of loud noises like fireworks and thunderstorms and hides while it is going on and for about an hour after it stops. We got her from our pound, who said she was 4 (She's already got some arthritis developing in her hips though), so we suspect she might be a bit older than that. We've had her for almost 2 years now.
In the time we've had her, she's been strictly on Blue Buffalo brand, but we switch flavors from Duck to Salmon to Chicken regularly so she does not get bored with her food (She's incredibly smart and stubborn). Her only health issue in the time we've had her started on July 4th of last year. My sister and I were both at work and did not see anything happen to her, but when I got home she was not right.
That night, the right side of her face was drooping, she had no control over her tongue, could not see out of her right eye, had poor motor control, and was still very anxious. Nothing in the house was torn up, no wrappers or anything anywhere. She did not get into anything she shouldn't have that night.
We brought her to the vet to have a check up on her and have her blood tested for any abnormalities. She was given a round of Clindamycin, but her blood test came back in normal ranges on everything. the round of antibiotics did not improve or have any notable affects on her.
She regained her motor control and some vision in her right eye as well as her tongue over a couple of months. Her facial nerve, unfortunately, was damaged too much for her to regain control of the right side of her face and it is still drooped. The vet thinks it might have been a seizure or stroke, but does not know for sure.
She went several months with no issues other than her anxiety, which she was prescribed Valium for. She only receives Valium when we know there will be a fireworks display or a thunderstorm on the way. If she's too anxious and none of those are impending, we try to get her focused on a puzzle toy or playing
This month, on the 4th, she had another episode. The previous day I had brought her and my puppy to the park for quite a long time (Approximately 2-3 hours since they are both high energy dogs and visit the park regularly) in an attempt to tire them out for the rest of the day. My sister's dog was starting to get a little sore, so we went home and relaxed for a little while before I started to clean the house up. Both dogs took a nap and were acting 100% normal.
On the 4th, she was normal in the morning, but when I got back from work around 3pm, she did not greet me or even know I was home. This is very irregular for her as she freaks out whenever she hears my car or the garage door. I wrote it off as she was still exhausted from the previous day, but when my sister got home she did not greet her either until my sister was right in front of her. We tested several squeeky toys and other noises to see if she was hearing. She could not hear anything. No voice, no toys, not even the door bell.
Since then she has been on house arrest. She went into the vet to get another blood test done as well as a check up. Blood test came back as completely normal, her ears are clean and clear, she does not act like she has an infection of any sort. She can hear the door bell and her squeeky toys now, but nothing else.
Has anyone else experienced anything like this at all? Our vet has no idea what it could be other than maybe a brain tumor.