My guess with your dog is like most breeders: you are not the full owner, you are more like the handler who keeps the dog for the breeder. Yes she can use this do for breeding if and when she wants without your permission. If you had a female you would have an extra contract for breeding since you either would be taking charge of the pregnancy and puppies or giving her to the breeder until the puppies are weaned. Since you own a male she doesn't necessarily need to ask you and you cannot charge her a stud fee either unless it is in the contract that she will pay you to breed her own dog. Not fair? Well most breeders consider the people they adopt out to as handlers who the dog will be living with and this is all common practice. You buy a quality dog from a quality breeder then expect that dog to be used for breeding by that breeder. If you don't want your dog bred then get a pet quality that the breeder will allow you to neuter.