Physical Changes
After being neutered, the most obvious physical change in male cats is that their testicles and scrotum are removed during the surgery. This leaves an incision site that is typically closed with dissolvable sutures, so no stitches need to be removed. The incision is located just in front of the scrotum and is usually about 1-2 inches long.
According to Tracy Veterinarians (https://www.tracyvets.com/site/blog/2022/04/29/neutering-male-cats-before-and-after), it’s also common for cats to experience some swelling and bruising around the incision for a few days after the surgery. This is temporary and should go away as the incision heals.
In addition to the surgery site, male cats that are neutered often gain weight more easily after the procedure. This is because neutering changes their metabolism. To prevent obesity, it’s important to monitor their food intake and exercise.
Neutering also causes changes in male cat behavior. They tend to become less aggressive, roam less, spray urine less, and can become more affectionate and attached to their owners according to The Wildest (https://www.thewildest.com/cat-behavior/male-cat-behavior-after-neutering). These behavior changes develop gradually over 2-6 months after the neutering surgery as testosterone levels decrease.
When Changes Occur After Neutering a Male Cat
Changes that occur in a male cat after neutering happen in stages. Some changes may be seen immediately after surgery, while others develop gradually over the next few weeks or months. Here’s an overview of the timeline for changes after neutering a male cat:
Immediately After Surgery
Right after the neutering procedure, your cat will be groggy from the anesthesia. He’ll need a quiet place to recover with limited activity[1]. You may notice some swelling or minor bleeding around the incision site[2]. Your cat’s scrotum will look enlarged and bruised from the surgery. He may seem slightly uncomfortable or restless. Provide a soft, comfortable area for him to rest as the anesthesia wears off over the next 24 hours.
Over the Next Few Weeks
Over the next couple of weeks, the incision will heal and the swelling and bruising around the surgery site will go down[3]. Your cat’s scrotum will shrink as the empty sacs retract. His energy levels and appetite should return to normal. You may notice some behavior changes as his hormone levels drop. He may seem calmer, less restless, and less likely to roam or try to escape[1].
In the Months After Surgery
In the months after being neutered, male cats often gain some weight as their metabolism changes[2]. They are less active and have lower energy requirements. You may continue to notice behavior changes related to the decrease in testosterone. Aggression, territorial marking, and roaming often decrease significantly[3]. Your cat will no longer have the urge to mate, and behaviors like yowling and spraying urine should stop.
Overall, the most significant changes after neutering happen within the first 3-6 months. Monitor your cat closely during this transition period. Contact your vet if you have any concerns about swelling, the incision, or changes in behavior or appetite.
[1] https://www.millplainvet.com/site/blog/2022/02/28/male-cat-neutering-recovery-behavior
[2] https://www.northbouldervet.com/site/blog/2022/03/30/male-cat-neutering-behavior-recovery
[3] https://www.brodheadsvillevet.com/site/blog/2023/04/15/male-cat-neutering-behavior-recovery
Incision Site
The incision for neutering is located just in front of the scrotum and penis. It is typically a small, straight incision less than 1 inch long. The incision may have dissolvable stitches under the skin as well as non-dissolvable stitches or surgical glue on top of the skin.
It’s important to prevent the cat from licking the incision site as this can cause infections. An Elizabethan collar may be placed on the cat to prevent licking. The non-dissolvable stitches are usually removed 10-14 days after surgery. According to VCA Animal Hospitals, “If your cat’s incision has non-dissolvable sutures, staples, or stent sutures, they are usually removed 10-14 days after surgery; the actual time depends on the preferences of the surgeon.”
Here are some pictures of typical neuter incision sites in cats a few days after surgery:
Image source: https://vcahospitals.com/know-your-pet/care-of-surgical-incisions-in-cats
Scrotum
After a cat is neutered, the scrotum will initially appear empty and have stitches where the incision was made to remove the testicles.1 The scrotum often still looks full at first, but this is normal as the skin takes time to shrink down.2 Over the next several weeks, the scrotum will gradually shrink and become less noticeable as it heals from the surgery.3 Proper aftercare and allowing the incision site to fully heal is important for optimal recovery.
Testicles
During a cat neuter surgery, both testicles are completely removed (excised). This is done through an incision in the scrotal sac so each testicle can be fully excised and detached from the body.
According to the VCA Animal Hospitals article “Cat Neutering and Behavior,” “The procedure involves general anesthesia, and an incision is made over each side of the scrotal sac so that each testicle can be excised or completely removed.”
Removing the testicles is the key part of neutering since it eliminates the main source of testosterone production and renders the cat unable to reproduce. The surgery ensures the cat cannot father kittens.
Energy Level
After being neutered, male cats tend to have a decrease in energy levels and roaming behavior. This is because neutering removes the testosterone that previously drove hormonal behaviors like roaming to find a mate and marking territory. According to The Wildest, male cats often become less restless and more content to stay at home after being neutered.
The reduction in testosterone also leads to less fighting and conflict behavior with other male cats. Intact male cats are driven to fight over mates and territory, but this urge is dramatically reduced after neutering. Overall, owners can expect their male cats to become calmer and less prone to roaming and marking inside and outside the home.
Weight Gain
One of the most common physical changes in cats after neutering is potential weight gain. This is primarily due to the fact that neutering causes a cat’s metabolism to slow down (Knutsford Vets Surgery). With a lower metabolism but no change in diet or exercise, a neutered cat can easily gain extra weight.
According to research, male cats may gain between 15-25% more weight in the months following neutering (Allaway 2017). This weight gain happens because neutering causes a decrease in testosterone and other hormones that affect energy usage and regulation of food intake.
To prevent excessive weight gain after neutering, it’s important to monitor your cat’s diet and activity levels. Switching to a low-calorie food formula made for neutered cats can help (Versele-Laga). Increasing play time and exercise can also help maintain an ideal weight post-neuter.
Behavior
After being neutered, male cats often demonstrate positive behavior changes like less roaming, spraying, fighting, and overall calmer demeanors (Cat Neutering and Behavior | VCA Animal Hospital). The hormonal influences of testosterone are decreased after neutering, which curbs many troublesome behaviors.
With lower testosterone levels, male cats are less likely to roam from their territory in search of females to mate with. Neutered males often stay closer to home (Neutering Male Cats: Behavior and Recovery Guide).
Territorial urine spraying is significantly reduced after neutering. Intact males may spray urine around the house to mark their territory, especially if other cats are nearby. Neutering eliminates this undesirable behavior.
Aggression and fighting are also decreased in neutered males due to the lowered testosterone. Intact males are often agitated and prone to picking fights with other males. After neutering, cats become more docile and mellow.
Overall, neutered male cats tend to be calmer and more mild-mannered. Their attention is less focused on mating behaviors, allowing their affectionate natures to shine through.
Health Benefits
Getting your male cat neutered provides several health benefits. According to the Animal League, neutering eliminates the risk of testicular cancer and greatly reduces the chance of prostate disease, perineal hernias, and anal tumors.1 Neutering also reduces undesirable behaviors like spraying, roaming, and fighting, which means fewer injuries and infections from bites and scratches.2
Specifically, neutering provides a near 100% reduction in the risk for testicular cancer, which is common in intact male cats. It also reduces the chance of prostate disease by 50-60% according to veterinary research.3 With lower testosterone levels post-neutering, male cats are less likely to roam, fight with other cats, and get injured as a result.
Aftercare
It is important to properly care for your cat after he has been neutered to ensure proper healing and prevent infection. [1] The main priorities for aftercare are checking the incision site, limiting activity, and administering any prescribed pain medications.
You will need to check the incision site twice daily to look for signs of infection like redness, swelling, discharge or opening of the incision. [2] It is normal for there to be a little redness and swelling right after surgery. Contact your vet if you notice any excessive swelling, discharge or the incision reopening.
Your cat will need to limit his activity after being neutered to allow proper healing. Keep him confined to a small space like a bathroom or spare bedroom. Restrict jumping and running. Short, leashed walks are ok but avoid strenuous play or exercise. [3] Follow your vet’s specific activity restrictions.
Make sure to give any pain medications as directed by your vet. This will help keep your cat comfortable while he recovers. Pay attention to his appetite and litter box habits, reporting any changes to your vet.