unexplained wet patch on dogs thigh

Does it smell of anything?
Was she in your view at all times up until you saw the wetness?

Edited to add... Sorry, I see you addressed the smell question. You're certain it's not pee?

Apoquel is the new skin wonderdrug
I haven't heard of side effects that describe what you describe, but it's so new that it might just not have been officially recorded yet.
I asked had you had your eye on her right up to the wet patch, because I had exactly the same thing happen to my little spaniel x, twice, whilst I was out. A wet patch on her outer thigh, no sign of anything to cause it... But it did smell of wee.
We got out answer a couple of months later... She had developed epilepsy and eventually had a seizure in front of me... She involuntarily pees herself mid-seizure but the pee dribbles from her lady parts without wetting her fur en route to her underside... It gathers between her thigh and her bedding. If I hadn't seen it so many times now, I wouldn't believe a dog could pee herself without an obvious trail back to the source

However, I also wonder... Have you noticed that the Apoquel makes her sleep very deeply? My little lady is on anti-seizure meds that cause her to sleep the sleep of the dead... And her brain doesn't always wake her up to tell her that her bladder's full Again, it wouldn't be unusual to find that her thigh is wet because she had peed in her sleep... This might be a more likely possibility, especially if you're certain she didn't have a seizure prior to the wet spot appearing.

Of all the drugs used to treat skin, Apoquel seems to be relatively benign in terms of lasting side-effects, other than some initial vomiting and/or diarrhoea. However, it is still very new so other things might crop up from time to time.
The drug my dog is on not only makes her sleep very deeply, it also makes her drink more, so although "peeing in her sleep" isn't listed as a possible side-effect, those two together, for her, combine to cause the problem.
So, there could be something like that going on.
That said, I knew a lady who had a dog on no meds at all, the dog happened to be a very deep sleeper, and occasionally peed in her sleep... Even if she happened to be lying on her owner at the time

jimf wrote: »

ah feck it dbb u know me too well :o

its an age thing in my case

I wouldn't know anything about that:o. Will have to take your word for it