The difference is that, in general, you’re dealing with less genetic diversity in a purebred than with a mix. So when a problem crops up in a purebred, it can be magnified by bad breeding practices.
Of course, many purebred breeders keep track of genetic defects so there is a record of hip dysplasia, PRA, cataracts, etc… People point to this as proof that purebreds have more issues than mixes. Since there is no data tracking health issues in mixed breeds, it can’t be refuted easily. However, this study suggests that there is no significant difference in the prevalence of hip dysplasia in mixes vs. purebreds: (warning .pdf) OFA Study
The latest fad is “designer” dogs - mixed breeds, sold for outrageous prices, under the guise of “hybrid vigor”. They claim that if you cross a beagle with a pug, you get the best of both worlds. What they fail to admit is that it also works the other way. Most of the breeders are cashing in on the craze and don’t do any health checks at all. They’ll breed a dog with bad hips to one with bad eyes and a nasty temper. Remember - “hybrid vigor” makes all those genetic disorders disappear like magic! :dubious: When these dogs fail to live up to the claims, they get dumped at the pound, lose their designer label and just become a pug/beagle cross. Now it’s a mutt, but it’s no healthier than it was before.
Most of these dogs are level 1 crosses - they took a beagle and a pug and stuck them together. The resulting offspring generally don’t have much uniformity - it’s a crap shoot what you will get. A true mutt, one bred from generations of animals outside of human control, probably is healthier - but we humans have our hands in everything.
So here’s my opinion, I will take a purebred dog from a good breeder because I know what I’m getting. It’s not a guarantee, but I’m pretty sure that the puppy I get is going to be free of health issues. I have a good idea what its energy level and personality will be like. I’m also pretty confident what I’m getting temperament wise because I’ve seen the parents and grandparents. A good breeder has generations of evidence backing this up. Of course, this takes a bit of homework and we all know we live in a society of instant gratification. People who don’t do their homework allow bad breeding practices to exist and create an environment where health issues flourish. People who are just out to make a buck know these people will buy their dogs from the pet store so they keep producing badly bred puppies year after year.
And just so no one thinks I’m a “show dog snob”, I believe that people who breed for fads in the show ring are just as guilty.
So all this “purebreds are bad. just bad” stuff in the other thread kinda pissed me off. I did my research and I got a healthy dog with a great temperament - it’s a Shiba Inu btw.
There are good breeders out there producing healthy wonderful purebreds. They’re just overshadowed by the bad ones making a quick buck on our throwaway attitudes and trend following.