Dogs neutered before puberty don't experience this rise in hormones and their long bones particularly continue to grow for a longer time resulting in greater height when growth does cease than their un-neutered counterparts.
This review discusses early-age neutering in the United States, and includes the review of scientific studies that have evaluated this procedure in puppies and kittens. Early-age neutering does not stunt growth in dogs or cats (a once-held belief), but may alter metabolic rates in cats.
Why does neutering cause weight gain? In simple terms, neutering alters your pets hormonal balance, which can lead to their metabolism slowing down. This means that the calories they do consume are converted to energy more slowly, meaning they need to take in fewer of them.
Having your dog spayed or neutered early will not stunt your puppy's growth, but it might affect the joints of large breed dogs. Studies show that early spay/neuter does affect the growth plate, delaying its closure and causing dogs to grow taller than they should have.
Removing the testicles removes the largest source of testosterone in the body. This results in a decrease in sexually driven behaviors in your dog: urine marking, escaping to seek female dogs, and aggression toward other male dogs.
While castration does not calm dogs down, it can reduce testosterone-driven actions such as mounting behaviour. It may increase a dog's focus or concentration.
The scrotum is often swollen in the first few days after surgery, leading some people to wonder if the procedure was really performed. If the dog is immature at the time of neutering, the empty scrotum will flatten out as he grows. If he is mature at the time of neuter, the empty scrotum will remain as a flap of skin.
The recommended age to neuter a male dog is between six and nine months. However, some pet owners have this procedure done at four months. Smaller dogs reach puberty sooner and can often have the procedure done sooner. Larger breeds may need to wait longer in order to properly develop before being neutered.
You may see the glans penis make an appearance from time to time, however. This occurs during sexual arousal, but even neutered males may get an erection when excited or overstimulated. During normal canine breeding, after ejaculation occurs the bulbus glandis enlarges.
Castration may make him slightly lazier, but don't expect it to have any effect on adolescent enthusiasm or rowdy behaviour either! If your dog has a behavioural issue, don't rely on castration as a “quick fix”. While it can help in some situations, it can make other problems much worse.
Benefits of Neutering (males):
Less desire to roam, therefore less likely to be injured in fights or auto accidents. Risk of testicular cancer is eliminated, and decreases incidence of prostate disease. Reduces number of unwanted cats/kittens/dogs/puppies. Decreases aggressive behavior, including dog bites.
Neutering will simply inhibit those instincts by lowering their testosterone. After neutering, your dog will be healthier, easier to train, and more affectionate. You won't have to chase after your dog as he chases a dog in heat.
Veterinarians use anesthesia on both species to ensure they remain pain-free and unconscious throughout the procedure. In dogs, an incision is made in front of the scrotum, and both testicles are pushed through this single incision and removed.
Neutering reduces marking in about 50% of dogs. Inter-male aggression can be reduced in about 60% of dogs. Dominance aggression can sometimes be reduced but behavioral modification is also needed for complete elimination.
Most controlled scientific studies on this question (and there have been many!) show that whether a dog is spayed or neutered has no impact at all on the likelihood that they will be aggressive in any given circumstance.
The most common type of altercation involves neutered males aggressing toward intact males. Neutered males smell like females. The scent of an intact male cause many neutered to react negatively toward them since intact males smell male.
The pain associated with spay or neuter surgeries is typically more of a discomfort and may last for just a few days and should be completely gone after about a week. If your pet is experiencing pain or discomfort for more than a couple of days it's a good idea to contact your vet for further advice.
Neutering your male dog or cat prevents testicular tumors and may prevent prostate problems. Neutering also decreases the possibility of perianal tumors and hernias, which are commonly observed in older, unaltered dogs.
A University of Georgia study, based on the medical records of more than 70,000 animal patients, found that the life expectancy of neutered male dogs was 13.8% longer and that of spayed female dogs was 26.3% longer.
Do not allow your dog to lick or scratch at the incision, as he may pull the sutures out and could introduce an infection into the incision. If the incision is not bandaged, inspect it at least twice daily. If a surgical drain was placed, you may be instructed to clean the drain several times per day.
While it's easy to pity a pet struggling with an e-collar, you must follow your veterinarian's directions and leave the cone on until you are directed to remove it. Usually, it takes about 14 days for the incision to completely heal.
Following a general anesthetic, some dogs cry and whimper quite loudly. Neutered dogs usually feel some degree of discomfort immediately following their procedure. It is not unusual for your dog to whine or whimper after being neutered, although some dogs can tolerate pain more than others.
Links between neutering and anxious behaviour appear more conclusive and consistent than aggression, with published evidence suggesting neutering is not an appropriate strategy for reducing anxious responses and may magnify anxious and fearful tendencies.