Originally Posted by hippiemade
What is going on?
I agree with littlefox that another trip to the vet is warranted.
temporary hearing loss could potentially be related to a number of factors such as an infection, a tumor/cyst in the middle ear or some kind of nerve damage (for example from standing too close to a loud sound/explosion, etc), head trauma, etc. The point is deafness is not black and white.
Just drawing from my own experience, I played for years in a jazz band (of course, without proper hearing protection *facepalm*) and I've been engaged in scuba diving for 35 years, of which 20 of those years involved intensive "technical" diving, which is to scuba diving what base jumping is to parachute jumping. This kind of diving can sometimes cause small bubbles to form in the middle ear.... (it's still worth it
The combination of those activities has left me with diminished hearing in both ears (high tones, mostly) and occasional noticeable tinnitus at F#9 (+/- two octaves above the highest register of the piano) particularly when I'm tired or ill.
Those things can interfere with hearing to the point of not understanding people clearly in a crowded room with a lot of background noise.
I'm telling you this because I can attest to one particular thing, which is that I think it's possible for tinnitus to become bad enough that you appear to be deaf and/or can't be bothered trying to listen.
If that tinnitus were to be short lived because of an infection or a head trauma, then it could -- to my mind -- be possible for your dog to have a sudden loss of hearing that subsequently went away.
I'm saying all of this to answer the question "what is going on". I *must* however, impress upon you that I have no medical knowledge to speak of and I am neither a vet nor a doctor. I'm just some older guy who played in a band, did a lot of scuba diving and is acutely aware of what that does to his hearing. Nothing more.