Prevention of pregnancy is the most common reason that rabbits are neutered, particularly if there are both male and female rabbits living together in a household. There are certainly enough rabbits in the world and too many are neglected or abandoned. One should not consider breeding these pets just for "fun" or "education".
In essence, the word "neuter" refers to the removal of the reproductive organs of either a male or a female of a species, although people frequently refer to the surgery in a female as a "spay". The scientific terminology for neutering in the male is castration and in the female is ovariohysterectomy.
• Prevention Of Uterine Cancer
This is the most compelling medical reason to neuter female rabbits. In some rabbit populations, the rate of malignant uterine cancer (specifically called uterine adenocarcinoma) can approach 80 percent of all the females.
Some rabbits may be genetically predisposed to uterine cancer, but it is unlikely that rabbit owners know the genetic backgrounds of their pets so surgery is a viable preventative option.
Uterine cancer can spread rapidly to other organs of the body such as the liver, lungs and even the skin and it is not treatable once it reaches this point. Rabbits under two years of age rarely develop this disease so it is best to neuter your bunny before it reaches this age.
Although cancer is the most common disease of the rabbit uterus we see many cases a year of other uterine diseases such as pyometra (infected uterus full of pus), uterine aneurism (uterus full of blood) and endometritis (inflamed uterine lining.
Like uterine cancer, these conditions are all more common in female rabbits over two years of age.
• Prevention Of False Pregnancies
Female rabbits can go into a hormonal state triggered by their ovaries where they think they are pregnant but they are not. Although this is not medically harmful, it can be very stressful for the rabbit that goes through all the motions of being pregnant including nest building, milk production and aggressive protection of its territory.
This aggression can be taken out on the caretakers and cage-mates and can make the pet very difficult to handle during this period. Some rabbits experiencing false pregnancy will develop a decreased appetite and have gastrointestinal disturbances as well.
• Prevention Of Mammary Gland Disease
Breast cancer is not common in female rabbits, but when it occurs it can spread rapidly and be very difficult to treat. It is preventable if the pet is neutered before two years of age.
The most common type of mammary cancer is a malignant form called mammary carcinoma and it is almost always associated with uterine cancer. The other common mammary gland disease is mammary dysplasia or cystic mammary glands. This is a benign condition, where the mammary glands fill with a cystic material. It can be uncomfortable to the pet.
Neutering a female rabbit before two years of age will prevent both of these diseases.
• Prevention Of Aggressive Behaviour
Both male and female rabbits can display aggressive behaviour when they reach sexual maturity. As they grow older, bunnies pick up defences such as biting, striking, chasing and snapping at you or each other. This is how they learn to protect themselves.
Neutering your bunnies shortly after they are sexually mature can greatly minimize their aggression.
• Prevention Of Urine Spraying
Both male and female rabbits spray urine on vertical surfaces to mark their territory. Intact mature males do this at least 10 times more frequently than females. Sexually mature male rabbits have urine that develops a very strong odour, which is unpleasant to many humans.
If this behaviour perpetuates, it may be impossible to retrain the pet, even if it is neutered after, to learn to use the litter box again.
• Prevention Of Testicular Disease
A disease of the testicles is rare in the male rabbit, but it can occur. Abscesses formed from bite wounds are most common. Others include hematomas (blood filled areas) and cancers.
Age To Neuter
The best age to neuter is shortly after sexual maturity. Depending on the breed, this could range from four to six months and with giant breeds up to possibly nine months.
Do not neuter your rabbit if it is younger than four months of age, not only is the surgery more difficult due to the immature condition of the reproductive organs (in males the testicles might not even be descended into the scrotal sacs prior to three months).
But the long term effects on the endocrine system of the body in lieu of the removal is unknown and may possibly be harmful. This has only been researched in mice and has been found to produce a weaker immune system in them.
Sexual maturity can be gauged in a number of ways including the presence of the testicles in the scrotal sacs, a well developed and possibly swollen vulva, a mature body condition and by behavioural changes such as urine spraying and increased aggression. Simple tests may be conducted prior to surgery to ascertain if your pet is ready to be neutered, particularly if your pet is older or has had other medical problems.
Obese animals and those that are sick are at risk and should not be neutered. Their existing problems should be remedied before neutering.
What happens at neutering:
1. The male rabbit's testicles are completely removed by way of making an incision in the area of the lower abdomen.
2. They may be left open or sealed with sutures or surgical glue.
3. Swelling may occur within 24-48 hours and will subside in seven to 10 days.
Note that male rabbits can still have living sperm (that can last for two weeks) in the portion of the spermatic cord (vas deferens), which is still in place after surgery. Testosterone blood levels will drop slowly after neutering and male rabbits will still try to mate with female rabbits for weeks after the testicles are removed.
After three weeks the sperm are dead and since no new sperm are being produced it is safe to put a male and female rabbit back together again.
1. The ovaries, oviducts, uterus and often both cervices are removed.
2. An incision is made approximately mid-abdomen and the uterus and associated structures are gently pulled out from the abdomen through this incision. The blood vessels supplying the uterus and ovaries are tied off with suture material and reproductive organs are removed. The incision is sutured with two to three layers of suture material.
It is beneficial to bury the final row of sutures under the skin so they are not accessible. In this way, the rabbit has nothing to chew on or pull out. These sutures eventually dissolve over several weeks and there are no external sutures to remove.
Skin staples may be used as a substitute, which also works nicely in rabbits, particularly the larger breeds. Skin staples cannot be chewed through like nylon suture or other more flexible materials.
Always check on the site of surgery at least twice a day to look for any signs of unusual swelling, discharges or gapping of the wound.
Most bunnies will not eat much after surgery but should regain their appetite over the next two to three days. Some rabbits may have clumped, soft and irregularly shaped stools but this should be righted when they begin to eat properly.
If your rabbit is acting very uncomfortable, is not eating at all, or is unwilling to move, you need to contact your veterinarian right away. Your veterinarian may prescribe a pain medication for your pet post-surgically, particularly for females that may have had any complications at surgery or for those that are older.
The long-term benefits of neutering far outweigh the temporary discomfort that might be felt.
*This article was updated on 15 Jul 2020. It first appeared in PetsMagazine.com on 5 Oct 2015.
Adapted from www.hrss.net