Now I want to see this study broken down by dog breed, or at least dog size. I also want to see "living in a home with a dog" broken out from "being primary own

Now I want to see this study broken down by dog breed, or at least dog size. I also want to see "living in a home with a dog" broken out from "being primary owner of a dog". The extreme cases are very different: if you live alone with a Border Collie, you're certainly going to be doing a lot of cardiovascular exercise; while if your roommate has a Pekingese, you might take it around the block occasionally when they're busy. I'm pretty confident that the Collie would be associated with improved cardiac outcomes, but it seems very possible that the Pekingese would too. There's decent evidence that adequate sleep on a regular schedule improves heart health, and even dogs that need minimal exercise can remind you about bedtime and breakfast time. And of course, having a dog probably lowers stress levels (in people who choose to get dogs), which is a straightforward improvement.