Breathing hard, as I said, could even be related to dehydration. So, there are a lot of possibilities.
Is there a vet university nearby that might be willing to offer a consult for you - and your vet? How about a friend/family/co-worker's vet as a consult?
Is there a vet university nearby that might be willing to offer a consult for you - and your vet? How about a friend/family/co-worker's vet as a consult?