When is a dog too old to breed?

I know that after a certain age you shouldn't breed a female, but does the same thing apply to male dogs? A friend has a pair of excellent collies that they breed together occasionally. The female is still young, under 5, but the male is 10. Is there any increase in risk to his health or the health of the puppies due to his age?These are working farm dogs, not show animals. And they aren't bred excessively; the last litter was born January 2006. There have just been some requests for pups recently, and I'm helping the family get some outside info.

If they aren't showing those dogs for points towards champion excellent or not they shouldn't be breeding plain and simple.At 10 that collie is an older man(senior) and as such is running a much greater chance of prostate cancer being an intact male.For obvious reasons she shouldn't be bred and also be spayed

With age, a dog's sperm loses vitality. It is just harder to get puppies.

At 10 years old a male should not used as a stud. Their sperm is less mobile and of a lesser quality than when they were younger. Also any genetic defects could possibly show up in the older males sperm because it is not of the higher quality as when he was younger. This doesn't mean he cant sire a litter it's just a matter of the quality of the pups.

I have heard of a 12 year old male being used at stud. He was throughly vet checked for heart, eyes and hips before being used. He sired a healthy litter of 5 pups. Ways to help potency are using wheatgerm oil and vitamin E.