Or maybe his disease is consequence from endogamy... ╮(￣▽￣)╭
in many "pure bred" animals there are a ton of defects from irresponsible breeders practicing incest and over breeding. That is why it is so important to know your breeder and look for a responsible one that is trying to better the breed and work out defects, not make quick cash with a puppy mill.
Mutts and human mutts are healthier.
I was also thinking the same!!! That "medicine" is too suspicious. Feels more like he has more colors or smth special and they are either too "elite" to have a child that is not like them or smth!!
i suspect that the pureblood might not be an actual pureblood?... like his heart is fine, but not his colors. maybe his father was experimenting on him? in case he might be the drug-producer and is related to the news on TV.