Through DNA testing, you can find out which breeds are involved, so you can customize your veterinary care. I watched a very interesting segment on Martha Stewart today. They tested two audience members' dogs.

Test your dog

Interesting! One of the advantages of having a mixed breed dog is that they don't have the health problems that many, if not most, purebreeds have as a result of inbreeding. I've always had mutts until just recently and they have never had the kind of quirky health problems the two purebreds I own now have turned out to have. Makes mixed breeds even more appealing, don't you think?

Oh yes , the mixed breed do not have the health problems. Sorry. Not true.
I have Oscar the love of my life, who is a pug x malt. He has cost us more than my pure breed Cairn terrier ever did and my pure breed pekingese. Both lived to an old age of 16 and the other 17 with illness at end stage.
Oscar has dry eye in both eyes that means Very expensive eye drops for life with eye animal specialist. Bladder stones - removed and they may come back . I watch him like a eagle when he pee's.
Eplilepsy - petite mal when under bad stress (came on at one groomer who we do not see anymore! Love to know if she drugged him or treated him poorly . Will never know. ). So, I think , as in life , its a gamble. Pure or mixed breed dog.

My 14-years-young pup is a collie/shepherd/who knows? mix and he is the healthiest dog I have ever known. I got him six months after losing my dalmation when she was not yet 6 years old to kidney failure. During the five years I had her, she was treated for more ailments and conditions than I care to enumerate.

I got a catalog in the mail, In the Company of Dogs, that has a DNA kit you can send for that is supposed to tell you the breed composition of your dog. $79.95.

Oh, too bad! My experience has been just the opposite. But the mixed breeds I was thinking of are the Heinz 57-type dogs, ones who are mixed for several generations back, not the cross-breed you describe. Cross-breeds I would think would be closer to purebreds. But it looks like you got lucky with your purebreds.

Mine, which are chihuahuas, are pretty health and hardy overall, but they have terrible teeth -- to the tune of $1000 per year to have their teeth cleaned. Our vet says the small breeds are notorious for having terrible teeth problems.

I think it's generally true that, the more diversity in the DNA, the healthier the dog is.

With purebreds, a lot depends on the breeder. A reputable breeder will try to "breed out" health problems in their dogs. An irresponsible one, only interested in money, will breed mother to son or brother to sister rather than pay stud fees for a nonrelated dog.