It contain proteins, vitamins , minerals and testosterone BUT you'd have to drink a lot more than your dog can actually produce to feel any little effect ^^
Unhealthy ? Nah, Healthy ? well, try it yourself ? lol, i don't think you should get any benefit from receiving dog sperm, either orally, anally, vaginally, etc.
Well, fucking is general is great for the body. I doubt dog sperm has any magic abilities though, but it would be hilarious if it was discovered to cure cancer or something. Imagine the poor normies having to take their medicine. lol