Celebrating Rabbits

Spay/Neuter: More Than Just Population Control

by Marie Mead
with assistance from Dr. Peg Frank

The most basic reason to spay or neuter a companion rabbit is to reduce overpopulation, which minimises the number of homeless rabbits who are euthanised. However, there are also important health and behaviour benefits.

Spayed and neutered rabbits often have a more comfortable life, as they are no longer driven by hormonal urges. In Living with a House Rabbit, authors Linda Dykes and Helen Flack note:

Neutering won’t change the underlying personality of an adult rabbit… [but he] will be more willing to interact with you, and he will be free from the frustration of the constant desire to mate.

In the House Rabbit Handbook, author Marinell Harriman states:

While spayed/neutered rabbits may be considered less “natural,” they are, in actuality, able to enjoy a more natural lifestyle, since they can run about freely together and work out social structures.

Adolescence

Many rabbits enter adolescence at about three months of age. The formerly sweet and cuddly baby bunny now begins to display a strong will, a desire for autonomy, and an innate impulse to chew and dig. Marinell Harriman observes:

The stage of intense curiosity, hyperactivity, and frantic chewing and digging occurs at the height of adolescence (4-8 months)…

Rabbit Reproduction

by Marie Mead

Rabbits are known for their reproductive capability and their adorable babies. Did you know…

  • Although 4 months is considered standard, some rabbits achieve sexual maturity as early as 2-1/2 months. Rabbits should not be bred at a young age, as it can create problems in both mother and offspring.
  • Female rabbits do not have specific fertility cycles. The act of mating induces ovulation, and pregnancy is nearly guaranteed. The gestation period for rabbits is basically a month (28-31 days).
  • A healthy doe can deliver 1-14 babies; the average number born to a mid-size rabbit is 6 or 7. A rabbit can become pregnant shortly after giving birth — incredibly stressful and unhealthy for the doe and her kits.

Pregnancy often occurs in young “same-sex” rabbits because it is difficult to properly sex them. Testicles are commonly carried inside the body of young rabbits, leading inexperienced observers to assume that a male is actually female.

Even if the male is immediately removed after discovery of his gender, a litter is often born about 30 days later.

Human guardians can prevent unwanted litters by becoming aware of the factors that affect sexual maturity and by separating male and female bunnies at the age of 10 weeks.

Much of this content is from Rabbits: Gentle Hearts, Valiant Spirits by Marie Mead, with collaborator Nancy LaRoche. Used with permission.

If not neutered or spayed, the maturing rabbit may display hormonally driven aggression, irritability, territorial marking, humping, nipping and biting.

Individuals who have not researched rabbits' needs and behaviours may now begin to lose patience with their bunny. This, in turn, often leads to abuse, neglect or abandonment.

On the other hand, informed guardians know how easy it is to overcome some of the more negative aspects of behaviour (e.g., “fixing” a rabbit results in easier litter-box training and a reduction in territorial spraying).

Marinell Harriman provides insight:

In terms of conforming to human standards of acceptable indoor behaviour…. Most rabbits don’t reach their full potential for a relationship with humans until after their first year. By this time too many humans have discarded them

Health Risks for Unaltered Rabbits: Cancer

Both male and female rabbits are susceptible to a variety of cancers, more common as the animal ages, though occurring in young ones as well. A few cancers can be sharply reduced by spaying or neutering at the appropriate age.

Since an unaltered male may develop testicular cancer, neutering by a qualified vet is recommended. Two common cancers — uterine and mammary adenocarcinoma — occur in unspayed females.

Uterine Cancer (Uterine Adenocarcinoma)

Unaltered female rabbits are at risk for uterine cancer by two years of age, and the probability increases as they age: it is estimated that 60% of unaltered females will have cancer by age four, 80-85% by age five.

Uterine cancer spreads to surrounding tissues and through the circulatory system to other sites, including the brain and bones. A rabbit may not exhibit noticeable signs in the early stages.

Dr. Peg Frank regularly treats rabbits from the Minnesota (US) Companion Rabbit Society. When she sees an unaltered rabbit urinating blood clots (not simply blood in the urine), the chances are that the bunny has cancer. Dr Frank shares this:

Blood clots in the urine are often the first sign of any abnormality that the caregiver sees. Ideally, before the surgery we would do a thorough physical exam and thoracic and abdominal radiographs to help rule out other causes of blood clots and to look for the spread of cancer to other tissues. An ultrasound can help confirm that the cancer is still contained.

After surgery — generally tumour removal and a complete spay — tissue pathology definitively determines the type of cancer. Dr. Frank continues:

When early-stage surgery removes the cancer while still contained, the prognosis is excellent and most rabbits live a full life. If the rabbit is not treated in the early stages, surgery is not effective because of the spread. In this case, the rabbit is severely compromised and the prognosis is very poor.

Cancer of Mammary Glands (Mammary Adenocarcinoma)

A female rabbit is less likely to experience this type of cancer if she is spayed before one year of age, advises Dr Frank.

There is a higher mortality risk with this cancer, as there is only a small window of opportunity to treat it. Because it travels through the lymphatic system, the cancer spreads throughout the body, including the brain and nervous system.

Finding a lump (usually the first sign of the disease) is often incidental: during playtime, while grooming, or — as is Dr Frank’s experience — during a veterinary exam.

The smallest lump I’ve felt was about the size of a BB…. A slightly discoloured (blood-tinged) discharge from the teat may be visible.

Depending on how quickly and to which organs the cancer metastasizes, other symptoms will become evident. The rabbit may stop grooming, playing, exercising, and interacting normally; these are all definitive signs that she needs pain control. Weight loss, equilibrium problems, and anorexia may also occur.

The Cost of Spay/Neuter Surgery

As of this writing, Lisa Hodgson (publisher of Bunny Mad) finds that spay fees in the UK range from £60- £120 ($95-$190 USD). Neutering a male is £40 and above.

Surgical costs may be a concern for some people. However, this can be put into perspective when one realises that not having a rabbit altered incurs expenses associated with behaviour issues, unwanted litters, and serious disease.

Adopting from a rescue group can save lives and money. According to Ms. Hodgson, a good percentage of organisations in the UK spay/neuter bunnies before they are adopted, and the adoption fee is generally low.

Some Tips on Spay/Neuter

by Marie Mead

Most vets prefer to spay a healthy female when she is between 4 and 6 months of age. Performing a spay before that age is technically difficult and may result in retained tissue, which can produce hormones throughout the rabbit’s life and result in behaviour problems. In addition, anaesthesia poses greater risks for small and/or young animals.

Healthy male rabbits can be neutered after their testicles descend; this sign of maturity can occur as early as 10 weeks of age in small and average-size rabbits, but may not be evident until giant breeds are 8 months old.

At the animal hospital

Having a quiet space for rabbits at the animal hospital — away from the sounds and smells of predators — will help reduce their stress, and a bunny buddy in the recovery cage usually provides comfort. Rabbits are seldom kept overnight since a quicker recovery tends to occur in familiar surroundings.

  • Rabbits should not be fasted prior to the spay/neuter surgery, but instead allowed to eat and drink normally; food residue should be removed from the mouth prior to surgery
  • The rabbit should be fully anesthetized
  • Pain medication is pivotal to the bunny’s recovery and return to normal eating and drinking
  • Eating and drinking after the surgery should be encouraged. If the bunny is in pain, syringe feeding may be necessary
  • During and immediately after the surgery, a rabbit’s temperature is likely to drop, and supplemental heat is essential to keep the body temperature stable.

At-home care

Caregivers will administer pain medication (obtained from the vet) and provide subcutaneous fluids and syringe feeding if necessary. One way to pique a rabbit’s interest in food is to offer some aromatic cooking herbs, such as fresh dill, basil and coriander.

Keep the rabbit in a warm indoor area and monitor body temperature, especially in the hours following the return home. Restricting movement is also advised, especially following a spay.

Some information was adapted from the article “Veterinary Care: Rabbit Basics” by Marie Mead, to be published (2010) in the revised edition of Rabbits: Gentle Hearts, Valiant Spirits by Marie Mead, with collaborator Nancy LaRoche. Used with permission.

References

  • BSAVA Manual of Rabbit Medicine and Surgery, Anna Meredith and Paul Flecknell, Eds. (British Small Animal Veterinary Association)
  • Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, Katherine E. Quesenberry and James W. Carpenter, Eds. (Saunders)
  • House Rabbit Handbook: How to Live with an Urban Rabbit by Marinell Harriman (Drollery Press)
  • Living with a House Rabbit by Linda Dykes and Helen Flack (Barron’s Educational Series)
  • Textbook of Rabbit Medicine by Frances Harcourt-Brown (Butterworth-Heinemann)

This article was written in support of the Make Mine Chocolate!™ campaign and was first published in Issue 8, Spring/Summer 2009, of Bunny Mad (“The magazine for bunny mad people!”), a United Kingdom publication. www.bunnycreations.co.uk. Used with permission.