Minimum Age to Spay/Neuter
Surgery in kittens that are too young is dangerous for two main reasons. First, they can get too cold and second, they can become hypoglycemic.
Anesthesia drugs can also be more difficult to dose correctly in a small kitten with a fast metabolism. Spaying a young kitten may also take longer because the reproductive organs are less developed and more difficult to locate.
- Body Heat
When under anesthesia, animals do not produce body heat. Small kittens will lose heat faster than a large cat.
There are many tools that veterinarians use to keep animals warm during surgery, but they can only do so much. Hot water blankets, heated tables, and warmed IV fluids will all help keep your kitten warm during its spay or neuter, but the less they are relied upon, the better.
Cats also need to be fasted before surgery. Vomiting food has to be prevented due to nausea from anesthesia medications.
Even with a shortened fast period before surgery, a young kitten may get dangerously low blood sugar. This is called hypoglycemia and although kittens can usually recover, this can be dangerous for their health.
The fast metabolism of a young kitten not only can cause hypoglycemia but makes it difficult to correctly dose anesthetic drugs. In combination with the increased difficulty of performing surgery on small patients, this can make anesthesia riskier.
- What is the Minimum?
Due to all of these factors, the minimum age for spaying or neutering a kitten is 8 weeks with at least 2 pounds of body weight. Many spay and neuter clinics have even more conservative minimums such as 12 weeks and 2.5 pounds.
Typically spays and neuters are performed near the minimum age and size when the kitten is up for adoption. Shelters do not want to adopt out unfixed animals but also want young kittens to grow up in a home rather than a shelter.
These shelters are usually very experienced in spaying and neutering young kittens and take precautions to make the procedure as safe as possible.
- Foster to Adopt: No Longer Pushing the Minimums
Some animal shelters and rescue groups are moving to a “foster to adopt” system so that kittens can go home sooner. A young kitten without a mother is likely to be much healthier in a home than in a shelter. Of course, the best part is you get more time to enjoy watching your cat grow up!
When shelters offer “foster to adopt”, the kitten is still technically owned by the animal shelter until it is spayed or neutered. A huge advantage of this system is that there is less of a rush to get fixed at a young age.
Just Before Puberty: The Ideal Age
Pediatric spay/neuter surgery is beneficial in many ways. Veterinarians report that it is an easy, fast procedure. Kittens that undergo surgery before twelve weeks of age report faster recovery and fewer complications.
Each cat is different. In the end, the decision falls into you and your veterinarian.
Even then, the rule of thumb is, the older the kitten, the safer the surgery. However, puberty can bring many bad habits and health issues as well as unwanted kittens.
Most veterinarians recommend spaying or neutering shortly before your cat reaches puberty.
Animal shelters typically spay and neuter kittens as young as possible. Most of them require kittens to be at least eight weeks old and two pounds in weight.
Kittens that already have a home typically wait longer. The ideal age for a cat to get spayed or neutered is around 4 to 5 months old when the kitten is a good size to handle.
Waiting to spay after a female’s first heat could open the door for ovarian or uterine cancers and diseases. In males, behavioral problems such as urine spraying and aggression are minimized with early neutering.
Most cats reach puberty by six months old, but they can mature sooner. Therefore, 4 to 5 months old is the ideal age to spay or neuter a cat.
‘Paw-sitive’ Benefits of Spaying or Neutering Before Puberty
The benefits could be observed in the following aspects:
- Spraying or Marking
Cats neutered while they are still kittens will not spray or mark. This extremely annoying behavior is more common in male cats.
If a cat has already formed this habit, there is some possibility that neutering will not fix it. For this reason, it is better to neuter before any marking behaviors start.
There are some ovarian and uterine cancers that can be completely avoided when a female kitten gets spayed.
For example, unspayed female cats are at extremely high risk for mammary cancer. Cats that are spayed before sexual maturity have almost zero risk of this type of cancer.
If a cat goes through its first heat cycle before getting spayed, its lifetime risk of mammary cancer is only reduced by 50%.
Castrating a male cat eliminates the risk of testicular cancer. It also prevents possible behavioral issues.
Male and female cats in heat have a strong instinct to roam in order to find mates. Even indoor-only cats have a way of escaping to roam the neighborhood looking for love.
This isn’t only a nuisance to your neighbors who likely don’t want to hear cats mating at night. Besides that, cats that roam are at risk of being hit by a car, getting in fights, and getting attacked by predators.
In addition to that, bad behavior that tomcats (mature adult male cats) typically exhibit are loud vocalizations, escape attempts, picking fights with other cats or animals, and marking their territory, like your house, with urine. Also, neutering male cats reduces the pungent odor of its urine.
- No Unwanted Kittens
Over one-million cats are euthanized in shelters every year in the United States. The biggest benefit to spaying and neutering may be helping prevent unwanted kittens.
Even if you are confident that you can find homes for any kittens born, these homes could instead be helping rescue a cat from the shelter.
Also, just as with human pregnancies, giving birth for cats isn’t without risks. There are many potential complications involved with a cat’s pregnancy; some of which could endanger your cat’s life.
Of course, spaying and neutering prevent unwanted kittens and this benefit can be seen at any age. Spaying or neutering after puberty will make the health and behavior benefits somewhat less effective.
Unlike some dog breeds, studies have shown that there is no advantage in waiting to get a cat fixed. Studies have found that there is only one noticeable difference between cats fixed before and after puberty.
The male cats neutered before sexual maturity grew to be slightly larger than the cats neutered at a later age. This is due to puberty hormones contributing to signals for cats to stop growing.
In unspayed female cats, uterine infections like Pyometra are extremely common. Your cat will need an emergency spay if one occurs.
It is much safer and less expensive to spay while your cat is healthy. Pyometra occurs after a heat cycle and can strike at any age, but is less common in young cats.
Getting a spay before or after puberty will equally eliminate the risk of this life-threatening infection.
Except in the case of uterine infection, spaying and neutering are considered elective surgeries. This means that if your cat has any sign of illness, veterinarians will wait to perform the spay or neuter.
Kittens are especially prone to runny eyes and upper respiratory infections. These kitten infections will delay when they can get surgery; sometimes for several weeks.
Very rarely, male cats will retain a testicle inside their abdomen. This is referred to as cryptorchid.
Neutering these cats is critical because the retained testicle almost always becomes cancerous. However, a cryptorchid cat will need to be at least four months old before surgery so that the testicle is developed enough to locate and identify.