My 9 year old lab had a splenectomy in April because the vet had seen a nodule on her spleen. The results came back negative and she appeared to pick up quickly after the op and was eating normally and enjoying her walks. Over the last two weeks her breathing has become noisy and she has become very lethargic. She is still eating normally, no weight change and bowel movements are normal. Although her fur is only just starting to grow back after the surgery. The vet has scanned her lungs and heart this week and not found anything. She's had blood test before the surgery for thyroid but that came back ok. Any thoughts?