Well, it does sound like that xray has shed a lot of light on Hamish's cough and it great news to hear that the cough responded and settled so quickly with treatment. Hopefully, with his continued treatment we won't see it again and he will continue to manage well for you.
Now in regards XXXXX XXXXX work-up for his heart condition, this is not as critical as the xray was. An echo is ideal and can help to tell us what kind of heart issue is present (ie which valve is struggling, how well or poorly the heart is beating, how thick the heart muscle is, etc) and this could allow your vet to head off specific issues with his heart condition and perhaps better tailor drug treatment for him.
Still, if funds are limited and you are not keen, then you can opt to have him on standard heart treatment. The choice of which drugs to use does depend on the vet's examination and xray findings. Generally speaking, we would usually use Frusemide (to remove fluid accumulation in the lungs) +/- ACE inhibitors (ie Fortekor
) +/- Vetmedin (More Info
) to help the heart beat more effectively as our baseline treatments for heart disease. So, one or both of these may also be useful for keeping Hamish's heart beating effectively and further reduce the volume of fluid that has been leaking into his lungs. Further to that, there are other medications used to manage heart conditions but again this depends heavily on their findings and suspicions for his heart disease.
Overall, an echo is an ideal but not an essential. Therefore, you don't have to have an echo at this point (or at all if you wished). Or you could always consider it as an option if his medication stops being helpful and the cough returns. But in regards XXXXX XXXXX question, it wouldn't be a required next step, especially if he is responding well to treatment thus far. Instead, perhaps speak to his vet about which medication would help his heart beat most effectively (since good heart function will also lower fluid leakage into lungs and help keep the dose of his Frusemide low) and keep him comfortable for you.
All the best,