Seriously, what are Collywobbles? Panic attack?
Not so much a panic attack as just plain fear. I’d say it’s somewhere around “butterflies in the stomach” fear. Etymologically, it seems to have been coined to mean something like “shaking guts”.
In the case of the linked article, it’s also a bad pun, since the dog in question is a fearful (hence “shaking”) Border Collie.
Actually Collywobbles would be such a cool name for a dog, especially if he was a collie 
…with an inner ear disorder? 
Fainting Collie Syndrome? 
Real Answer for Collywobbles: Aren’t they the British version of what Americans call ‘butterflies in the stomach’ ? I always thought it was a funny word when I read it, and it sounds much more upset and “quakey” than the Americanism.
My grandmother uses the word to mean an upset stomach generally – diarrhea included, most often.
That’s one of the definitions, anyway, though I’ve seldom seen it used that way. There seems to be some disagreement as to whether it arose from “cholera morbus” or from a portmanteau of “colic” and “wobble”. I’ll admit that the latter sounds like a folk etymology.
I’m pretty sure the collie was running, rather than having the runs, though.
I thought it related to Collingwood, an Australian Rules Football team.
Interesting combination of subject matter and user name…
While it sounds like folk etymology, the OED accepts it.