Well, if your one and only purpose in having your dog neutered is preventing him from fathering puppies, you could choose a vasectomy. Some veterinarians will perform this procedure, which will sterilize a dog but leave the genitals intact. It’s a more difficult and time-consuming procedure than castration, and also more expensive.
A vasectomy doesn’t provide all of the benefits of a full castration, however, which is why some veterinarians won’t perform it. It doesn’t protect against testicular tumors, which are common in older, intact males. It also doesn’t protect against testosterone-influenced diseases, such as perianal hernia and perianal adenomas.
Also, because testosterone is still present in a dog’s system after a vasectomy, your dog would still exhibit the behavior of a dog that hasn’t been neutered. He would still try to go through the motions of mating with female dogs, for example. He would probably fight with other dogs to defend his territory and breeding rights, and he would mark his territory (inside and outside) with urine. He would also have the urge to roam to find mating partners.
If your main concern is having your dog look intact after surgery, you can have him castrated and have testicle implants placed in his scrotum. These are surgically placed inside your dog’s tissue, much like breast implants. With these implants, your dog can be castrated without changing in appearance.
For more information on the advantages of neutering or spaying your pet, see Neutering Your Pet.