If you're able to go to that cardiologist, I definatly would. A lot of the time it can be handled with proper medication and they can life for a long time. General practitioning vets most of the time aren't familiar enough with all the available specialty medications, especially new ones, and how to combine them etc. so a vet cardio. should be able to help you out alot.
Good luck, hope you can find help for Dayton (p.s - that's my son's name too
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