puppy panting and heavy breathing

hi guys, i recently i noticed my puppy gets in these spells of heavy panting and sticking her tongue out coupled with excessive thirst. she won’t be doing too much physical activity but somehow starts getting like that. she’ll breathe super hard while awake and then asleep. i took her to the vet today and she told me not to worry, since her energy levels and appetite have not changed.

i have noticed she’ll get tired a lil more easily after pottying though. im super worried. has anyone else had this happen with their pup? 🙁