The researchers, led by animal geneticist Dr. Danika Bannasch, determined the level of inbreeding for 227 different breeds using Wisdom Health Genetics’ DNA testing dataset of 49,378 dogs. She found, “The majority of dog breeds display high levels of inbreeding well above what would be considered safe for either humans or wild animal populations.”

Just 11 of the 227 analyzed breeds had an inbreeding score of 0.125 or less, equivalent to a cross between two half-siblings. The vast majority scored above 0.25, a value you would expect if two siblings or a parent and offspring reproduced.

The researchers then paired this inbreeding information with pet insurance data from the company Agria, which provided the rate of non-routine veterinary care events per 10,000 dog-years for each breed. With these figures, Bannasch and her colleagues calculated that, on average, purebred dogs require 24.4% more non-routine vet visits than mixed breed dogs. These are visits for injuries, diseases, or other unexpected maladies.