[header] How to promote safe whelping for older dogs [title] Avoid breeding a dog over six years old. [step] Depending on breed, it's best to mate your dog between the ages of two and six. A pregnancy after age six can pose significant health risks to both the mother and pups, even if the mother was in good health before the pregnancy. 
If your dog is pregnant at an older age, you will need to stay in close contact with its vet throughout the pregnancy. [substeps] It's always wise to take your dog to the vet for a pre-breeding exam before mating it, regardless of age.