dog breeding

Question
Hi,  I have a male and female black labrador aged 7 and 3 respectively.  Are they too old to breed.  My male keeps mounting my female - she is presenting herself but then turns to snap at him, is there anything I can do to prevent this so that they are able to mate?

Answer
Age-wise, they are fine.  However, the only way to KNOW if the male is able to sire a litter is to have a vet look at his semen for viability.  I am assuming you have clearances on both dogs, because if you don't you could be passing on health problems.  

Many times 2 dogs that live together have problems mating, the bitch will not allow the male to mount her.  If the dogs have clearances, you MAY want to contact a breeder-mentor or your vet about doing a side by side AI.