Well its there way of cooling themselves down its almost like sweating through their tongue so don't worry she/hes cooling down. If it is very heavy panting and your dogs behavior changes dramatically visit the vet
It might be the food you are feeding your dog take her/him to a vet he/she may be very ill
Thats just what dogs do like cats they like to clean them selves so leave your dog alone or give it a good wash down hope this helped
hydrated means that there is water present
