Doggie panic attack?

[Cheenabug]

I am lucky to have a very friendly, people-loving, very calm Chihuahua. She was a rescue, and as far as anyone can tell, is pushing about 11 years old. Regular vet check-ups have always revealed that Cheena is in good health, especially for her age.

Starting around a year or so ago, Cheena seemed to start developing a great fear of beeping noises (mostly loud, such as the smoke detector low-battery beep). She seemed to have a sort of panic attack over it. She would crawl into the coldest, darkest place she could find, and sit there shaking and salivating. Wouldn't come out for a walk, treats, or anything. She might get over it after 15 minutes or so, or it could take hours before she's back to acting normal. I have no clue why this started, or how I should react to it for her. I've tried calming her a few incidents, and I've tried ignoring her during others, to see if she'll get over it herself.

Her last "panic attack" seemed pretty extreme. Not only did she exhibit the above behaviors, she actually seemed to have an elevated temperature. I usually guage her general temperature by feeling her ears, and they were very hot, as was her nose. I didn't know what else to do, so I gave her a cool-water rinse in the tub. While that lowered her temperature to what I consider normal, she didn't react in her regular way after the bath (usually happily running around, trying to rub the water off her fur onto the carpet), she was still shaking. I know most Chihuahuas shake a lot anyways, but mine rarely does unless she's genuinely cold or scared.

I have mentioned this to a few vets who don't seem to have any ideas. We now have a new window unit AC that beeps and scares her. This is a pretty big problem, seeing as how the summer has just started. Other than these doggie panic attacks, she's a healthy, very well behaved little dog. I'm concerned for her, but I have no clue what I can do.

[chihuahuagrandma]

You know sometimes in Chi's disorder or diseases do not come to head till a more mature age...thats why I asked if you'd ever done bloodwork...its costly, usually around $100, but it rules out a lot of things or rules in something...
If its emotional, well, you have a bit of a challenge...yes, they shake...but...mine don't really shake a lot or tremor, it would have to be a rain storm for one, and shes shimmers really bad and pants and panics and her temp will change and we really try hard to know when the storms comes to help her thru it, for the stress causes conditions to come on like convulsions now diagnosed w/Cushings...one shakes and shivers at loud bangs, such as door to the dryer, or garage door electronically coming down, and we try to cater by talking em thru it...my worse one is the one you cannot scream or loud tone of voice, we loose him under the bed for at least an hour and hes different for a long time, and hes never been abused and born in my home..hes just sensitive...
You as an owner would best know, but, you say its a recent set of events and hasn't been like this in past history, thats why I ask you if you did bloodwork...something must be trigger thats news, or medical internal...

[Cheenabug]

No, I haven't had any bloodwork done. Just basic check-ups and the routine required/recommended shots. Is there anything you would suggest they look for, if I were to take her in for bloodwork? I've had her for about 6 years, with no major problems, so I've never thought of asking about it.

[chihuahuagrandma]

I have Chi's also, 5 of them now...did you vet every do bloodwork?