Dog pants with little exercise; cat pants with tongue out after exercise – is it a heart problem?

Panting after exercise is usually normal for cats, but it cannot rule out early heart disease; cats with cardiomyopathies also pant with an open mouth and protruding tongue. Watch the symptoms closely, and if unsure, get regular cardiac ultrasound at the vet to find the cause and treat it correctly.

Rapid panting can also come from heat or thirst in hot weather. It may also be from swallowing a foreign object, such as a bone stuck in the throat, which also causes open-mouth, tongue-out rapid panting.