Q: What are the pros and cons of pediatric spaying and neutering? Is the early procedure more dangerous than the standard procedure? Does it affect behavior? Our local veterinarians do not neuter until the animal is approximately 7 months old. Does the early procedure require additional training? What is the youngest age at which you recommend spaying or neutering?

A: Today, many (perhaps even most) veterinarians perform the procedure on a cat who is between 5 and 7 months of age, but there is very little scientific evidence to suggest that this age is the best. This recommendation was established when anesthetic and surgical techniques were perhaps not as safe as they are today, so to ensure a favorable surgical outcome, the procedure was reserved for more mature cats. Most veterinarians are comfortable performing the surgery on cats this age, and there is certainly nothing wrong with it. My only concern is that the surgery be done before puberty to prevent unwanted pregnancies as well as certain behavioral problems (like increased aggression and marking behaviors) and physical problems (like mammary cancer).

Efficient reproducers
Overpopulation of homeless dogs and cats is a terrible problem in this country. Millions of cats are euthanized every year because there are not enough homes for them. Countless others die from exposure, injury, disease, or starvation. To their detriment, cats are remarkably efficient reproducers. For example, suppose one male and one female cat is allowed to reproduce for one year, and that eight kittens-four males and four females-are born. Assume that none of the kittens dies and that the kittens from each of the resulting litters are also allowed to reproduce for a year (which would actually be an underestimate because female cats can produce kittens throughout much of their lifetimes). At the end of seven years, almost 175,000 cats would be born! The Humane Society of the United States estimates that 2,500 to 3,000 dogs and cats are born in this country every hour. (By comparison, only 450 humans are born every hour in the U.S. according to the U.S. Census Bureau).

Many animal shelters have mandatory post-adoption spay/neuter policies, but over half the clients do not comply, even when there is a financial incentive. Of owners who comply, many fail to have the procedure performed before an unwanted pregnancy. In a recent survey of cat owners, 87% reported that their female cats were spayed, but almost 90% said their cat had had at least one or two litters before they'd had the procedure performed. When asked why they had allowed this to happen, the majority reported that they'd thought the cat was too young to become pregnant. (Recall that a female cat can become pregnant as early as four months of age).

Is it safe?
To circumvent this problem, many animal adoption agencies require that kittens (and puppies) be spayed or neutered prior to adoption: thus the interest in pediatric sterilization. Justifiably, many have questioned whether there are any negative short- or long-term health or behavioral effects associated with performing the procedure in animals as young as 6 weeks of age. However, studies of cats up to 3 years after early spaying/neutering have demonstrated no adverse effects. Longer studies will be helpful, but so far, the results are encouraging.

Although no special training is needed beyond that required for performing the procedure in older cats, spaying or neutering these youngsters requires some special precautions. Fortunately, safe techniques have been developed-anesthetic and surgical complications appear no more frequently in this age group-and most veterinarians familiar with the procedure can perform the surgery more quickly than when done at the traditional age. Another plus: kittens recover from surgery more rapidly than do patients operated on at the more traditional age. Often the kittens will be up and playing within two hours after surgery.