Since your Labrador is going through a heat period it is a good time for her to mate. The age of dogs is an important factor in mating along with some other parameters. Before you pick a partner for her, you must keep certain things in mind.Before choosing a mating partner for your dog, enquire from the owner if it is a registered dog. This way you can register the litter easily when born. Any partner that you choose for your Labrador must complement her well in her physical attributes.You should pick a dog whose bloodline makes up for any weakness in your bitch’s bloodline. For instance, if your Labrador does not have a glossy coat, you can pick a Labrador who has a good coat of hair. This will not guarantee good hair for the litter but it will improve the chances. The mating partner for your dog must balance any flaws in her. Studying the pedigree of the mate for your Labrador will give you a good idea about him. Dog owners always get complete information at the time of adoption from dog breeders. You must ensure that the genealogy of the mating partner is good. There should not be any severe medical ailments mentioned in it. This is why getting a purebred partner for your dog is important. Crossbred dogs sometimes face medical problems later in life. Dogs sometimes become infertile due to genetic and hereditary abnormalities. You can do tests to check for genetic problems that the offspring may get from parents. The health and temperament of a dog are important along with the physical appearance.A dog’s temperament is a hereditary trait but external factors can influence it. If the dog you have picked for your bitch displays aggressive behavior, the litter may inherit it. Do not pick a dog with such behavior as it may even harm your Labrador.The best time for a Labrador bitch to mate is during her third heat cycle which is after two years. Thus, it is the perfect time for your Labrador to mate. Male dogs are active sexually even till old age and the dog referred by your doctor is only 7 years old. He still has several fertile years left. You can always get a semen quality and quantity test report of the dog. This will let you know if you should select him as the mate for your Labrador. You can ask the owner to provide you with the medical records of the dog.Once you have finalized the mate, you need to get a stud contract made. This contract will be between you and the owner of the mate. You need to be clear about the ownership of the litter before you sign up your dog for mating.Get a pre-mating health check-up of your Labrador once you have selected her mate. This would include a physical examination by a veterinarian. She should have a good muscle tone and should not be overweight. Make sure you get all her vaccinations done before she mates.