The World Small Animal Veterinary Association (WSAVA) have recently published their first reproduction control guidelines for dogs and cats. These guidelines have been put together by the WSAVA Reproduction Control Committee and reflect the latest evidence in neutering practices. The guidelines recommend a move away from a blanket neutering policy, and a shift towards a more targeting approach to the neutering of pets.

What did the WSAVA look at when producing these guidelines?

The WSAVA brought together world-renowned experts and international stakeholders to develop guidelines. They looked at surgical and non-surgical neutering, explored the health benefits and risks of these procedures, and examined the ethical aspects of reproductive control in dogs and cats. 

What were their conclusions regarding surgical neutering practices?

The group found that there are several different surgical approaches to neutering that are practised worldwide. They noted that the main reason complications might occur, whatever the approach, was ‘inadequate exposure’. In other words, the surgeon might not have made a big enough incision to be able to clearly visualise the surgical field.  

Recommendations for keyhole spays

The committee also found that when neutering (or spaying) a female dog, an ovariectomy (removal of the ovaries) is preferred to a full ovariohysterectomy (removal of the ovaries and uterus), unless the uterus is diseased. The reason for this is that without the ovaries, the uterus won’t usually cause a problem if left within the body, and the surgery can then be quicker and less invasive for the animal. The group recommended a keyhole or laparoscopic approach to neutering, when this is available and not cost-prohibitive. This marks a shift away from the traditional ovariohysterectomy approach. 

Strong advise against over-use of antibiotics…

The group also looked at the need for antibiotics when a patient undergoes a neutering procedure. Although surgical site infections can be a concern in dogs and cats, it’s not recommended that antibiotics are routinely given as a preventative measure. Instead, the focus should be around keeping the procedure short, maintaining surgical sterility, and having a clean environment to perform the procedure. 

…or under-use of painkillers

Neutering surgeries, as is the case with all surgical procedures, are painful. The WSAVA recommends pain relief is given for every surgical neutering procedure, and this must be sufficient for the individual circumstances of the patient and must cover the whole perioperative period. The recommendation is to give ‘multimodal’ anaesthesia, which means multiple types of pain relief, so that pain is controlled in the most effective way.

What was the advice around non-surgical methods of neutering?

Not all pet owners want their pet to be surgically neutered, and in some areas of the world, surgical neutering is not an available option. Non-surgical neutering can be achieved by:

Hormonal downregulation 

This involves administering hormones like progestogens, androgens, or deslorelin implants to reversibly shut down the hormone-releasing centres in the brain. Sometimes, these can be administered as a long-acting implant. This treatment is not suitable for every animal.


This involves injecting a vaccine that binds to hormones and suppresses reproductive hormone production. The vaccine doesn’t last long though and requires multiple injections.  

Intratesticular chemical castration

An injection is injected into the testicles to prevent sperm production, and in some cases, brings about a reduction in testosterone too. Adverse reactions can occur, and the procedure currently lacks long-term evidence for safety and efficacy. 

Gene therapy

This is a relatively new treatment technique that makes use of the body’s natural processes, to control genes that are associated with the production of reproductive hormones. Currently, there is little research available to see how well this treatment works in the live animal.

What were the WSAVA’s recommendations overall, about neutering dogs and cats?

Removal of the gonads (organs that produce sex hormones; the ovaries in females, or testicles in males) can bring health benefits for some animals while causing problems for others. Vets must explain the pros and cons behind performing the procedure and take individual circumstances into account.

The WSAVA felt it advisable to leave both male and female dogs intact, where these animals are kept by responsible owners, unless there are specific reasons for neutering that individual dog

This was particularly advisable for certain breeds prone to developing health issues post-neuter. However, the owner would need to be watchful for the development of certain conditions such as mammary and vaginal tumours, pyometra and other reproductive diseases. For many owners there is inconvenience associated with leaving a female dog intact, due to risks of unwanted pregnancy and managing bloody vaginal discharge. The WSAVA recommends deslorelin implants or ovariectomy as an alternative. If surgical neutering is chosen for a female dog, this should generally be carried out after the first or second heat ideally. 

In a canine shelter setting, the WSAVA suggests waiting for a potential owner to come forward before a decision is made on neutering options. 

The situation is different for cats though

Currently, it’s recommended that female cats are neutered pre-pubertally, before they reach four months of age. Male cats can also be neutered at this age, without detrimental effects on life expectancy, health, and behaviour. Removing the testicles in cats is generally recommended because it eliminates unwanted behavioural traits. It’s known that neutered cats have an increased risk of weight gain; but this can be managed by feeding an appropriate diet and encouraging exercise. Any other health detriments associated with neutering before four months of age have not been definitively proven, and overall, the benefits of neutering at this time outweigh any potential concerns. 

What ethical concerns did the WSAVA have around neutering?

Besides health concerns for individual animals, other factors, such as ethical considerations, practices at shelters and pet overpopulation also have to be considered. 

The WSAVA noted that while pet overpopulation remains an important problem to be tackled, it’s not clear whether low-cost spay and neuter programs have led to a reduction in the numbers of animals coming into shelters. Similarly, Trap, Neuter, Return (TNR) programs to control feral animal populations might not deliver the desired long-term outcomes. Mandatory spaying and neutering laws in some countries may also not be as effective as hoped. 

In summary:

The WSAVA summarises that there are still a lot of areas where data and evidence is lacking around neutering practices. And further work is needed if we are to fully understand the impact of neutering on the pet population. Many will see these recommendations as controversial, but given the weakness of much of the data, the committee seem to have come down on the side of caution for now. For the individual animal, neutering decisions should be made carefully; weighing up the risks, benefits, individual circumstances and the wider implications for the pet population. 

As the WSAVA Committee say,

“Ultimately, the decision whether and how to spay, neuter or sterilise an animal should be based on a thorough assessment of the individual animal’s health and client preferences. Veterinarians play a crucial role in guiding these decisions, weighing the risks and benefits to ensure the best outcome for the animal, the client, and the broader community.”