Fido has an appointment at the vet or a spay/neuter clinic, and when he comes home he won't have testicles. In a nutshell, that's what to expect when neutering your male dog. Ideally, dogs undergo the operation at about 6 months of age, before reaching sexual maturity. That doesn't mean older dogs or younger ones -- at least 2 months of age -- can't have the surgery. It's wise to neuter your pet before he develops some of the undesirable behaviors of intact male dogs.
You'll likely be instructed to withhold food and possibly water the night before the operation. Your dog receives general anesthesia prior to the surgery. The vet makes an incision in front of the scrotum and removes the testicles. The incision might or might not have stitches. If you opted for a low-cost spay/neuter clinic, it's likely there won't be external stitches, as these facilities usually don't have animals return for suture removal. At a spay/neuter clinic, your dog goes home the evening of the surgery. At a private vet, he may or may not stay overnight.
Recovering From Surgery
It might take your pet a day or so to recover from the anesthesia, so he's likely to seem "out of it" when he first comes home. After that, most dogs recover quite quickly. Fido may have to wear an Elizabethan collar for a week or so to prevent him from licking or biting at the incision site. Keep your dog's activity limited the first week post-surgery, until the incision is fully healed. If the incision bleeds or appears infected, take your dog to the vet immediately.
Neutering offers far more benefits than simply keeping sex off of your dog's mind. Neutered canines won't develop testicular cancer, and the procedure lessens the odds of prostate cancer. Once altered, aggression toward other male dogs usually decreases, it if doesn't disappear altogether. Neutering won't make a dog lazy or fat -- that occurs because of too little exercise food and too much food. If your Yorkie or Chihuahua enjoys leg humping or mounting, or the tendency to roam, you should see less of these not-so-charming behaviors. He'll still engage in some urine marking, but not as often as when he was intact.
You might not have to pay as much for an annual dog license, as some municipalities charge less for neutered pets. Another benefit -- you should enjoy his company longer, as a neutered dog usually outlives an intact male, all other things being equal.