The panting could be a sign of serious dehydration. Make sure your cat gets plenty of liquids and if you find the cat is not drinking then you will need to have the vet inject liquids intraveniously. We had to do this with our kitty who was shriveling up to skin and bones right before our eyes. We only had to do it twice before we discovered ''cat sip'' a milk product that she loves and drinks all the time now.