[alpayton]

From what I understand if you've got a sick one, that in itself can cause the enlarged heart. I'd ask your vet to further explain this. Ask the vet if this diagnosis is something that could be caused by the ongoing problem that you're having with the illness (coughing and so forth).

I have had one of my babies xrayed lately and one of the comments by my vet was "his heart isn't enlarged by this yet" so I am really tending to think that this enlarged heart thing isn't really a separate diagnosis. It's a secondary diagnosis related to the cough and congestion that your little one has had. Get rid of the cough and congestion and you'll get rid of the enlarged heart.

Please call back and ask to speak to your vet again. I'd definitely want to clarify this.