But the 'respiratory distress' was just the panting. And that was investigated and there was found to be no health problem causing it. Presumably the vet would have noted the symptom that he presented with (the panting) and investigated it accordingly. If it was only his heart that was investigated, then I would assume from that that the vet didn't think anything else needed investigating. If the vet didn't say that the 'respiratory distress' could be caused by something other than a heart problem, and didn't recommend any further investigation, I can't see how Axa could possibly claim it was related to any possible future respiratory problems. And I wouldn't have thought your vet would say anything other than that. Especially if a fair amount of time has lapsed (eg, say he is diagnosed with asthma in 5 years time. Axa might say that the 'respiratory distress' originally investigated was actually asthma. But given that he hadn't exprienced any respiratory distress or asthma symptoms in the meantime, and that asthma wasn't suggested when he was investigated first time around,and if your vet would be happy to say that s/he doesn't think there is a link, then I can't see there being a problem). I would just go ahead and change. But it might be wise first to have a chat with your vet about it all - what did s/he say when the heart tests were all negative? Was she happy to accept that the panting was just a result of strenuous exercise and not indicative of anything sinister?