Neutering Your Male Dog – Castration

What is castration?

The operation involves surgical removal of both testicles via an incision in front of your dog’s scrotum. It is a straightforward operation performed under general anaesthesia.  Your dog will be admitted as a ‘day patient’ and following a pre-operative check by your veterinary surgeon, he will be given a pre-medication and analgesic (pain killing) injection prior to his general anaesthetic. After surgery and following his recovery from the anaesthetic he will be ready to go home later the same day. You will be given full discharge instructions on how best to care for your dog after surgery and he will be checked by your veterinary nurse 3 days later to ensure the wound is healing. If there are any sutures present these will be removed 10 days later. Your dog will go home with some pain relief medication for a few days and a Buster collar if required to prevent any interfering with their wound.

What are the advantages of castration?

Medical – Male dogs are prone to several medical conditions.  Enlargement of the prostate, testicular tumours and certain types of anal tumours are relatively common in older entire dogs.  Removal of the testicles minimises the chances of there being problems in later life.

Retained testicles (cryptorchidism) – This is a condition where by one or both of the testicles have failed to move into the scrotum and are still in your dog’s groin or abdomen.  If the testicles have not descended by the time your dog is 8 months old they are probably unlikely to move any further. When the testicles are retained they are at a higher temperature than in the scrotum. This leads to infertility and an increased likelihood of the testicle becoming cancerous. Removal of the testicle(s) is therefore still recommended but the operation may be a bit more complicated as the abdomen may need to be entered.

Unwanted puppies – Thousands of unwanted dogs are destroyed every year due to ‘accidental matings’.  Being responsible for your dog’s actions will greatly reduce the stray dog problem in this country.

Behavioural problems – Once a dog has reached puberty at about six months they may start showing male characteristics such as mounting or aggression.  This sort of behaviour is generally considered antisocial and unacceptable.   Certain behavioural problems such as dominance, aggression, urine marking and roaming may be improved with castration.  However castration should not be looked at as ‘the answer’ to all bad behaviour and will not stop a dog being ‘bouncy’ for example.  Also while hormones are responsible for some behaviour initially, your dog may continue with these behavioural problems out of habit. If you are unsure of whether castration will help in your dog’s situation you should consult your veterinary surgeon to discuss the problem.

Are there any disadvantages?

The operation carries a small risk associated with general anaesthesia.  Your dog will be assessed prior to surgery to ensure he is fit and well for the procedure, and full instructions will be given when he goes home to minimise the chances of a problem occurring with the wound.

It is a common fallacy that a neutered dog will become fat and lazy. They may have a decreased activity level following neutering, which in turn causes weight gain IF your dog continues to be fed the same amount of food as before they were neutered. Neutered pets can require up to a 30% reduction in their feeding requirements. This is due to no longer utilising energy in to reproduction. This extra energy may then be stored as excess body fat instead.

After your dog is neutered, we recommend moving him onto a neutered dog food. Royal Canin have developed a competitively priced, veterinary exclusive pet food, Royal Canin VetCare Nutrition range. This food is high in protein and low in fat to help combat against any weight gain. Your veterinary nurse will be able to advise you on the best feeding regime for your dog.

When to castrate?

The best time for castration is 6 – 12 months of age (depending on breed) at the onset of puberty although adult dogs can be castrated at any age.

Are there any alternatives?

There are two non-surgical options which can be used for temporary effects:

One is an implant given by injection which blocks the production of hormones suspending the fertility of sexually mature male dogs for a minimum of 6 months. The other is an anti-male hormone injection. Two injections may be required and its effect is short lived (3 – 4 weeks).  There can be side effects and your dog would need to have a health check so it is important that you discuss these options further with your veterinary surgeon if you require more information.

Useful links:

Neutering Your Male Rabbit – Castration

What is castration?
This operation involves surgical removal of both testes via an incision over or in front of your rabbit’s scrotum. It is a straightforward operation performed under general anaesthesia. Your rabbit will be admitted as a ‘day patient’ and following a pre-operative check by your veterinary surgeon, he will be given an injection of a combination of sedative and analgesic (pain killing) drugs to induce anaesthesia. After surgery and following recovery from the anaesthetic he will be ready to go home later the same day. You will be given full discharge instructions on how best to care for your rabbit after surgery and he will be checked by your veterinary nurse 3 days later to ensure the wound is healing. There are generally not any sutures that require removal 10 days later as we usually use intradermal (under the skin) sutures in rabbits as they have a tendency to gnaw on them! We will however request a post operative check 10 days following surgery to ensure that their wound has completely healed. While the wound is healing we recommended only using newspaper as bedding as hay or sawdust can get caught in the wound and be a tract for infection. Hay should still be provided in the diet but not used as bedding. Your rabbit may go home with some pain relief medication for a few days.

What are the advantages of castration?

  • No unwanted kittens (baby rabbits) if housed with an entire female
  • To help prevent behavioural problems such as aggression
  • No testicular tumours

Are there any disadvantages?

Any surgical procedure involving general anaesthesia carries a small risk but unfortunately rabbits do have an increased risk of death under anaesthesia. This is quite a complex issue but it is mainly due to them being prey animals which makes them respond to stress differently than cats or dogs. The physical and psychological effects of stress can unfortunately result in a fatality during surgery or in their recovery period. Luckily anaesthetic complications are relatively rare in rabbits and every care is taken to ensure this does not happen. Many advances have been made in regards to the anaesthetic agents used for rabbits. If you have any concerns relating to the anaesthetic please speak to your veterinary surgeon for more advice.

Following a stressful procedure like surgery, rabbits can often suffer from reduced gut motility or gut stasis. This is when their digestive system slows down.  It is vitally important that your rabbit continues to eat normally following surgery and any changes in their appetite should be reported to your veterinary surgeon or veterinary nurse. Supportive care may be needed to increase your rabbit’s appetite. It is also helpful to monitor the faecal output of your rabbit following surgery and any reduction in droppings should also be reported.

Following neutering it is not uncommon for your rabbit to gain weight. This is due to their energy requirements decreasing due to the reduction in hormone production. Careful monitoring of their diet and an increase in exercise will help to ensure this doesn’t happen. Your veterinary nurse will be able to advise you further.

If you have 2 rabbits of a different sex living together you must ensure that they are kept separate for at least 6 weeks following surgery as they may still be capable of reproducing.

When to castrate?

Rabbits can be castrated from 4 months of age (as long as their testicles have descended) or later in life if required. The anaesthetic risk increases in older rabbits so the surgery is best performed when your rabbit is still young to provide the optimum benefits.

Useful links:
Neutering Your Female Rabbit

Rabbit Castration Advice

Once you have made an appointment for your pet to be neutered, it is important that your pet eats as normal up to their operation, therefore food and water should NOT be removed the night before the procedure.

Once admitted they will be examined by your vet and given a health check.

Rabbits are given a combination of drugs to induce general anaesthesia.   Once your pet has had a health check and the vet is happy to proceed, the combination drug is given into the muscle.  This injection will take 5 – 10 minutes to take effect. They will then be under general anaesthesia.  He will then be transferred through to the Prep room and prepared for theatre.

An endotracheal tube may be placed into his trachea to maintain a clear airway for us to give him oxygen and if necessary a gaseous anaesthetic to maintain anaesthesia.


Once asleep under anaesthetic he will be prepared for theatre.  His veterinary nurse monitors his anaesthetic while shaving an area of hair from his testicles.  Once the hair has been removed the area is then cleaned using an antiseptic soap. This procedure is carried out to reduce any bacteria on the skin and provide a sterile operation site. All the hair will grow back in time. He is then transferred to theatre.

The nurse will carefully monitor the anaesthetic during the surgery.  The vet will perform the castration by firstly making an incision in front of the scrotum. Each testicle is then clamped, tied off with suture material and then removed.  This is a permanent and irreversible procedure.

Once the surgery is complete another injection is then given into the muscle. This injection reverses the initial injection and can take a further 10 minutes for your pet to be fully awake. During this time he will be constantly monitored by the Hospital nurse and is kept warm.

Once he is sitting up and alert, the Hospital nurse will contact you to update you on their progress and arrange a collection time. On discharge a veterinary nurse will explain all the necessary post-operative care.

It is advised that rabbits are kept separate from entire females for 6-8 weeks to prevent any unwanted pregnancies.

We will only discharge a patient when we feel they are fully awake and are able to walk. Some pets take longer to fully recover than others and are treated on a case by case situation, so don’t panic if a late time is requested for collection.

Benefits of having your rabbit castrated:

  • Improves social interaction
  • Can reduce fighting with other rabbits (and guinea pigs if kept in mixed hutch)
  • Can be kept with entire female rabbits