I just realized this is a side affect of the pred my dog is taking! I thought it was just the heat. Is this serious? do I need to take him to the after hours clinic? Any thing I can do in the mean time? Thanks.
I would call and see what they say.
As long as he is not having trouble breathing then typically no, you don’t need to bring him in. However, WHY he is on Pred can affect that answer.
Panting, increased thirst and urination are all common side effects of prednisone. Generally, when the dose is tapered down the side effects also decrease.
So, heavy panting can be normal - or it could be a symptom of something else (especially if he has been on pred a while, and this is a new thing).
Why is he on pred, and is it long term or a tapering trial?
He has been on it for 7 days for sever itching/allergic reaction to something . 40 lbs 10 months old.
1/2 of a 20mg tab 2x/day for 5 days, then 1/2 tab 1x/day for 5 days, then 1/2tab every other day until finished.
Vet warned me he might be drinking and peeing more, which he is. He seems OK, eating and playing etc all normal. Just panting a lot.
Sorry I didn’t get a chance to get back to you last night, I would call your vet this am, just to touch base but that doesn’t sound overly concerning to me.
I agree its very likely from the high dose of prednisone, you should notice is decrease after the dose is reduced. 
Make sure not to limit his water.
Put a call in to our vet this A.M. He said to watch him and now that we are tapering the dose he should improve. My Thanks to you all!
The panting will get better as you start decreasing his dosage.
Long term use of Prednisone has some pretty nasty side effects including muscle atrophy. My dog had to be on it long term after suffering from acute polyarthritis that persisted. Over time I was able to taper it down to just a small amount and it helped him live a normal enjoyable life for a long time with minimal side effects.
Be careful not to take your dog off pred suddenly - you have to gradually taper.
Just aim to eventually give the minimal amount your dog needs, make sure he has access to plenty of water and keep him out of the heat as much as possible.
