The research, the history and the medical side of neutering cats early.
Vets have traditionally neutered at 6–8 months. There is no scientific basis for this; it is simply how things have always been done. Current data show convincingly that early neutering at 8–16 weeks is not only safe but also gives the animal more benefits.
Sex hormones are the main reason animals run off looking for a mate. Remove the source of the hormones and the urge goes.
Males become much less territorial and much less inclined to fight. 80% of cats hit by cars are unneutered males.
Marking territory is hormone-driven behaviour. Early neutering reduces it more effectively than an operation in adulthood.
Neutered cats live healthier lives: fewer injuries from fights and escapes, and no risk of reproductive cancers.
Early neutering slightly delays the closure of the growth plates. The animals grow a little longer and leaner, and this is not considered a problem.
Only 20% of pet cats have a litter before they are spayed. Each unspayed female has an average of 2.1 litters a year, with 4–5 kittens in each.
The growth plates close slightly later, so the long bones end up a little longer. There is no scientific evidence that this is a problem. Anecdotal observations agree: these animals are leaner and taller, and they live longer.
In males the penis stays juvenile, but urethral diameter and urinary function are the same in animals neutered at 7 weeks and at 7 months. Urinary stones depend only on diet and genetics, not on the age at neutering.
Neutered animals need 30% fewer calories. Spayed females are twice as prone to obesity, but they live longer. Obesity is a matter of diet and activity, not of the operation itself.
The University of Colorado has published detailed data on anaesthesia in kittens aged 7–16 weeks: when the protocol is followed, the operation is safe. Modern drugs have cut the risks considerably since the 1990s.
Kittens sold as pets leave us already neutered. This is a requirement, not a recommendation: it is about the animal's health and a responsible approach to breeding.
The ideal age to neuter our four-legged friends is 8–16 weeks.
Neutering before puberty was hotly debated for many years. As a result, a great deal of scientific research, independent studies and anecdotal evidence has built up. The Medford Humane Society in Oregon finally decided to spay or neuter every animal in its care before it went to a new home. Why?
They realised that many of the animals they had rehomed were producing offspring that ended up back in the shelter, in an endless cycle. In 1987 Dr Leo Lieberman raised the question of early neutering in his paper "A case for neutering pups and kittens at two months of age". While the shelter in Medford, Oregon is considered the birthplace of early neutering, Dr Leo Lieberman is considered its father.
Many institutions have contributed to what we now know about this in relation to pet overpopulation:
The 1990s produced a large body of data on the subject, which allowed vets to go further. The growing scientific literature would not have been possible without data from animal welfare societies, private vets, specialist spay and neuter clinics and the owners of pets neutered before puberty.
Yet even with all this effort, in 30–60% of cases owners broke the terms of their contract and did not have their animals neutered. Animal welfare societies, which rehome 20–25% of our four-legged friends every year, are adding to overpopulation without realising it. Here early neutering could become the main weapon against it.
Euthanasia is still the leading cause of death in cats and dogs. With 70 million dogs, 75 million pet cats and countless doomed animals, vets are fighting an endless battle. After hundreds of attempts and efforts, we find it disheartening that overpopulation is still the main problem for animal welfare societies. But knowing that, thanks to neutering, fewer animals are put to sleep every year gives hope for a brighter future.
The conventional age for neutering in veterinary practice is 6–8 months. There is no scientific basis for it; it simply became a tradition. Some of the more conservative vets found the new approach hard to accept.
Animal welfare societies have put too much effort into housing and rehoming animals and not enough into education, behaviour programmes and programmes that promote neutering. While many have already accepted early neutering as a necessity, many people still take on unneutered animals.
Given that dogs are 15 times and cats 45 times more prolific than humans, it follows that on the one hand we are on the way to solving overpopulation, and on the other it keeps growing.
Only about 20% of pet cats have a litter before they are spayed. By comparison, 75% of stray cats are in heat, pregnant or nursing kittens, all year round.
On average each female has 2.1 litters a year with 4.25 kittens per litter, and these figures are rising. Even so, 40% of kittens die in their first 2 months and 60–80% before sexual maturity (5 months); the figures vary, but the "carnage" does not get any smaller. In this respect a pet cat is luckier: as a real household pet it is healthier and lives longer.
Early neutering is a very useful tool against pet overpopulation. A lot has been learned recently about its medical side. Many questions have been raised, including euthanasia and how it affects animal numbers. But the main questions still concerned early neutering itself: its effect on behaviour, obesity, skeletal growth and urethral diameter, and the anaesthesia and surgery.
Neutering cuts escapes by 90%, aggression in males by 60% and marking by 50%, adds 1–3 years to a dog's life and 3–5 years to a cat's, and generally makes for a better pet. Early neutering improves these figures further. About 50% of surrendered animals have not been neutered at the time they are given up, and about 80% of dogs hit by cars or hurt in dog fights are unneutered males. Clearly an unneutered male dog is a danger to himself and to other dogs. When dogs and cats reach sexual maturity, sex hormones can change their behaviour dramatically. By removing the source of these hormones we can reduce or even eliminate unwanted behaviour, and fairly simply.
Obesity depends directly on an animal's diet, activity level and age. Spayed females are twice as likely to become obese, but they live longer and tend to lead more sheltered lives. Neutered animals also need 30% fewer calories. And many neutered animals never put on weight at all. Obesity, in people and animals alike, is mainly an American problem. Years of work with stray animals have shown that neutered animals that are not obese live healthier and happier lives than their unneutered counterparts. Early neutering delays the point at which an animal starts to suffer from obesity, but it is far from the main cause. A suitable diet and exercise keep an animal in shape for as long as possible.
Sex hormones also affect skeletal growth. Early neutering delays the closure of the growth plates, so the long bones grow slightly longer. There is currently no scientific evidence that this is a problem. Even anecdotal evidence confirms that animals neutered early are leaner, taller and healthier, and live longer.
Urinary problems are one of the most common concerns. Scientific and anecdotal evidence point to the same conclusion: early neutering is necessary and beneficial. In males neutered before puberty the penis is juvenile, but urethral diameter and urinary function do not differ between animals neutered at 7 weeks and at 7 months. Every vet should know that urinary stones depend only on diet and genetic predisposition. There is no point in waiting until the animal is older: neutering early brings more benefits. As for urinary incontinence, the literature contains many contradictory findings and conclusions. The scientific data show that 4–20% of spayed female dogs and 0.4–8% of unspayed female dogs suffer from it. Another established fact: large-breed dogs are far more prone to it than small breeds. Many factors, including breed, thyroid function, allergies and obesity, are sometimes not taken into account. It is not logical to assume that a lack of oestrogen causes incontinence, and research supports this view. Why, then, don't pregnant females join the ranks of those with incontinence, when their oestrogen levels are negligible? Obesity (which can be controlled) and an underactive thyroid may well be the main factors behind incontinence. It is now being confirmed that females spayed early are actually less prone to incontinence than those spayed at the "traditional" age. Neutered animals have more advantages than unneutered ones.
Anaesthesia and surgical techniques for neutering kittens and puppies early are now well developed. The main question is how the young ones cope with the anaesthetic, given that their metabolism is faster than an adult's and their blood volume lower. The statistics show that young animals have fewer adverse reactions to anaesthesia and come round (recover) better than animals operated on when older.
These are the keys to a successful early neutering:
Experience shows the fewest complications when kittens are neutered at 12 weeks and puppies at 16 weeks. The optimal operating time is 3–6 minutes for kittens and 4–8 minutes for puppies. So for young animals the surgery takes less time and less anaesthetic, they come round and recover faster, and there are practically never any problems after the operation.
Dogs spayed early never develop ovarian or uterine tumours or pyometra, and they never come into heat.
Mammary cancer (the number one problem in dogs and number three in cats) is almost entirely ruled out in animals neutered early. Testicular cancer is the number two problem in dogs, and 60% of unneutered male dogs have prostate problems by the age of five. Perineal tumours are the most common problem in male dogs and are directly linked to testosterone levels.
The research, the literature and the anecdotal evidence are clear. Early neutering has far more advantages than disadvantages. It should become the main weapon against pet overpopulation. Animals neutered early are much healthier and happier, and they make any rehoming programme more successful.
Have a look at the kittens available at Home in Raksi