One of my BC's has started rapid breathing within the last month. We have been to the vet, his heart rate is fine, did a blood test, (showed up fine), have done an xray of the lungs (nothing wrong).
The dog is not sore anywhere so don't believe he is in pain, as he is acting normal in every other way, still loves to play and is very active and no problem with eating.
What could be causing this? I know the weather is getting hotter, but he breathes faster even on a cool night and at complete rest.
What shall we be checking next?