using 4 generations of pedigree data his coefficient of inbreeding is 14.06%. but pedigree calculation assumes that any prior ancestors have zero blood relation which is rarely the case, so it's very likely this dog could even be a few points higher on a genetic COI test
for reference 12.5% would be the same as a half-sibling mating and 25% would be a full sibling mating. definitely not ideal but acceptable to some old school breeders, attitudes are steadily changing and there's absolutely health-minded breeders out there that would never breed this close.
deleterious effects of inbreeding generally begin after 5% and many livestock farmers try to set a limit of 6%, however most purebred dogs circle around 24% and even <40% isn't unheard of in some breeds.