Strange breathing problems, vet is stumped

She was on antibiotics twice, it sounded like she got a little better, but then it continued

Haha i didn’t even notice that she had gotten on the keyboard. Sneaky thing

The tumor could be a possibility, but its hard to tell if her chest is protruding because she is a very very tiny cat. She is 10 months old and only about 3-4 pounds. That’ll be something else i’ll bring up to the vet.