minnie my female did that when she had her pup , her teets was so full and hard and hot. I took her to the vet and he put her on antibiotics and told me not to worry so much that she would be fine. i think it was 5 days the swelling was down and she finally stopped panting. I had the AC on for her and the pup had a heating pad. Now he is a mischevious bouncing boy at 6 weeks , getting into everything. Good luck on the new babes
