Just adding a note so I can get subsequent comments via email throughout the day.

Dr Coates, I have to take exception to your comment that generally mutts are healthier than purebreds. Can you cite any credible sources?

In the case of purebreds, you have just cited resources for people concerned about purebred's health. Why do those resources exist? Because breeders care deeply about reducing or eliminating any health issues that may exist within a given breed, and support testing and research. Who is doing that for the mutts of the world?

Mutts are a combination of various breeds, as designer dogs are: when you get that kind of a mixture how does one even begin to predict what health issues a family might have to watch for as a puppy grows? Purebred breeders do have a good idea and can advise new owners what, if anything needs to be tested for in the future,
and what needs to be watched for. That information should give a veterinarian a much better chance in many instances, of helping a family if their pet comes in for a health issue.

A proud and responsible purebred dog breeder.

This study is in Denmark. And.. it shows that some pure breed dogs live longer than mixed breeds. and that ..surprise.. larger dogs do not live as long as smaller ones. This is a fact no matter if the dog is pure bred or mixed.. if you breed a Great Dane to a Irish Wolfhound .. chances are it will not live as long as a Sheltie. No surprise there..
Mixed breed dogs are probably less likely to see the vet as often as pure bred dogs. Pure bred dogs need health checks for breeding and other health checks.. plus since vets continue to say "mixed breeds " are healthier.. why would a person with a mixed breed dogs take it in for anything routine. They would think.. heck it is a 'mixed breed" the vet say they are helahtier so why have them checked.. seems this defeats your own purpose.
Also Denmark has no "overpopulation " problem .. and in fact has fewer castrated animals. go figure.
However before we let Denmark off the hook they do have despicable breed specific laws..
on July 1 of 2010, Denmark banned 13 breds of dogs, including the pit bull terrier, Tosa Inu, American Staffordshire Terrier, Fila Brasileiro, Dogo Argentino, American Bulldog, Boerboel, Kangal, 3 breeds of Ovtcharkas, Tornjak and Sarplanina.

Isn't this prior to most DNA testing for inherited disease? While responsible breeders worked very hard to avoid genetic mutations, it was much more difficult prior to DNA testing for these diseases. Often dogs were several years old and already had offspring before they could be diagnosed with a particular disease.

Either you respect that pedigreed animals represent unique characteristics that are worth preserving, or you don't. Certainly it is much easier to fit a predictable type and temperament and even size into most people's households. Many people aren't willing to take the random chance that a "mutt" will fit into their lifestyle. That's the value of the pedigreed animal - their predictability. That includes being able to predict what diseases might affect the dog - instead of randomizing all of them as does a mutt.

Anne

"I bet many of you purebred folks are familiar with at least a couple of these sites, but a few might be new even to you."

yes we are.. know why?/ because we take our pets health seriously and we take our breeding stock seriously. WE contribute to these data bases. just as you say we are familiar with these important data bases.. we also have CREATED them.
Just as you bet we are familiar with these data base I can almost guarantee you that owners of 'rescue' and "shelter dogs" are not. While their dogs benefit from the information few of them participate and contribute to any of the information found on any of these sites Makes you wonder where you get the idea that "mutts" are healthier than pure breds..
why would any vet think :
"which of the deadly diseases that boxers are prone to will get him in the end,"?/ what an attitude.
Personally I think you should stick to mutts. It does not sound like you are "proud' to own a Boxer.. ( please tell me that you are not his "mom"..)

I don't want to get into an argument about whether or not purebred dogs are better than mixed breed. But...about your boxer. If your boxer came from a breeder who knows their lines, does genetic testing, OFA's ect., who breeds carefully to eliminate (as much as possible) the problems boxers are prone to, then I would suggest that you have less to worry about than with your mutts whose lineage is unknown. Dog shows are not just beauty contests and breeders care about much more than creating champions! I'm not a breeder and it has taken me half a lifetime to fully understand what makes a "good breeder" and how to find one. My Lab is not only beautiful, she's sound in body and mind, is healthy and I don't expect to face PRA or EIC or epilepsy or hip dysplasia with her. It isn't a matter of luck, it's about good breeding. There are no guarantees with living creatures but it sure is possible to stack the odds in your favor and that is not true with a mixed breed.