This is a really interesting article about a study conducted over 20 years.
I was dismayed that chihuahuas die most often of cardiovascular disease. Recently I brought both boys in for their vet visit. Mr. Wiggins (a mini-pin rescue from Louisiana) was having a heart worm check up (he passed! ...no more heartworm!) and Renaldo (a chi-dachshund mix from a local shelter) was getting his full yearly. I also get him a six-month check up with complete blood work and a poop test, now that he's a senior. I was advised that Renaldo has developed a heart murmur and would need an echocardiogram. The echo showed no severe damage but the vet also wanted two xrays to establish a base line of what his heart looks like, and adviced me to get an echo each year from now on.
I was betwixt and between but ultimately opted for knowing what his heart looks like now, so we can be prepared as he ages. There is medication that can slow heart disease but fortuantely he didn't even need that yet. So while an echo in my neck of the woods cost $360, I do feel a great deal of comfort knowing what we're dealing with. Seeing this study released confirms that I made the right decision in optin for extra testing.
Knowing what your breed or breed-mix is predisposed to can help you look for signs and get early treatment. Dog care is much like people care. Identify a problem early and you can get a handle on it.