Deciding whether to neuter or spay a dog or cat is one of the most common questions families raise during consultations. It is an important decision that goes far beyond preventing unwanted litters: it has proven effects on the health, longevity and behaviour of our pets. Here we explain, clearly and rigorously, what sterilisation is, how it differs from castration, what benefits it offers, what the procedure involves and how to debunk some widespread myths. As always, the final word rests with your vet after assessing your animal individually.
What sterilisation is and how it differs from castration
Although in everyday language we use both terms almost as synonyms, technically they do not mean exactly the same thing. It is worth understanding the difference so you can speak accurately with your vet.
Sterilisation
Sterilisation is any technique that prevents the animal from reproducing without necessarily removing all of the reproductive organs. By extension, in day-to-day use it serves as a general term for any procedure that prevents reproduction, in both males and females.
Castration
Castration involves the removal of the gonads: the ovaries (and, depending on the technique, also the uterus) in females, and the testicles in males. By eliminating the production of sex hormones, in addition to preventing reproduction, it provides health and behavioural benefits that simple sterilisation does not always offer. It is the most common option in dogs and cats.
Benefits for health and behaviour
Beyond controlling the animal population, the main reason for recommending this procedure is health. When carried out at the right time, it helps prevent serious problems and, in many cases, contributes to a longer and calmer life.
Health benefits
In females, the removal of the ovaries and uterus significantly reduces the risk of mammary tumours when performed early, and completely eliminates the risk of pyometra, a serious and potentially fatal uterine infection that frequently appears in intact females of a certain age. In males, prostate problems and testicular tumours are prevented, and certain risky behaviours are reduced. Good preventive health also relies on keeping check-ups and vaccinations up to date: here we explain which vaccines your dog needs and which vaccines your cat needs.
Behavioural benefits
As the influence of sex hormones disappears, many animals display more stable behaviour: less tendency to run off in search of a mate, less urine marking, fewer fights between males and, in cats, a notable reduction in the meowing and restlessness associated with heat. It is worth remembering that castration is not a magic solution for every behavioural problem, which often has an educational or management origin, but it does usually make living together easier.
Differences between dogs and cats, males and females
Not all animals benefit equally or in the same way. Recommendations vary depending on the species, sex, breed and lifestyle. The following table summarises, as a guide, the main benefits; your vet will tailor the advice to your particular case.
| Species and sex | Main benefits | Things to consider |
|---|---|---|
| Female dog | Lower risk of mammary tumours and prevention of pyometra; end of heat cycles and bleeding | The benefit is greater the earlier it is performed, according to veterinary judgement |
| Male dog | Prevention of prostate problems and testicular tumours; fewer escapes and less marking | In large breeds it is worth assessing the timing of development |
| Female cat | Prevention of pyometra and reduced risk of mammary tumours; end of noisy heat cycles | Also recommended for indoor cats |
| Male cat | Less urine marking, fewer fights and escapes; lower risk of infection | Especially useful in cats with outdoor access |
As you can see, for both indoor cats and house dogs the procedure offers clear health advantages, even when their risk of reproduction is low.
At what age it is recommended
This is probably the most frequent question, and also the one that least allows for fixed answers. The ideal age depends on the species, breed, size and health status of each animal. In general, the procedure is usually considered once the animal has reached a sufficient degree of maturity, but there are important nuances: in large-breed dogs, for example, it is sometimes preferable to wait for greater development, while in cats the criteria may differ.
The ideal age depends on the species, breed, size and health status of each animal: what really matters is that you consult your vet, who will advise you on the optimal time.
That is why we avoid giving rigid figures: what really matters is that you consult your vet, who will assess your pet and advise you on the optimal time. This individualised approach is part of the basic care from when the animal is very young, in which prevention is always the best strategy.
“The decision to neuter should be made calmly and well-informed; we assess each case to advise you on the best time.”
The procedure and the recovery period
Castration is one of the most frequent and routine surgeries in veterinary practice, which does not mean it should be taken lightly: it is always performed under general anaesthesia, with an appropriate safety and monitoring protocol.
What the procedure involves
Before surgery it is usual to carry out a prior assessment (a physical examination and, depending on the case, blood tests) to minimise risks. The procedure consists of removing the gonads through an incision that is closed with sutures. In females it is abdominal surgery that is somewhat more involved than in males, but equally safe when performed under appropriate conditions. If you want to learn how we work, you can see our veterinary surgery unit.
Postoperative care
Recovery is usually quick. During the first few days it is advisable to keep the animal calm, prevent it from licking or biting the wound (with an Elizabethan collar or a surgical garment), limit intense exercise and follow the medication guidelines to the letter. Most pets return to their normal life in a short time. At any sign of inflammation, persistent pain or loss of appetite, the best thing to do is to contact the clinic.
Common myths about sterilisation
Many mistaken ideas circulate around this procedure and create unnecessary doubts. Let's clear up the most common ones.
| Myth | Reality |
|---|---|
| "My pet will definitely get fat" | After surgery the energy needs change, but weight is controlled by adjusting the diet and maintaining exercise. It is not inevitable. |
| "It's better for her to have a litter first" | There is no proven health benefit to having had offspring beforehand; in fact, delaying the procedure can reduce some protective effects. |
| "It will completely change their character" | Certain hormone-linked behaviours are reduced, but the personality and the bond with the family remain. |
| "It's a very dangerous surgery" | It is a routine and safe procedure when performed with the appropriate prior assessment and monitoring. |
The weight-gain myth deserves a separate explanation, as it is the most widespread and the one that worries families the most.
The "it makes them fat" myth: how to manage weight
It is true that, after the procedure, the metabolism becomes somewhat more efficient and the appetite may increase, so with the same food as before the animal could gain weight. But this is not an inevitable consequence of the surgery, rather a perfectly manageable effect. The key lies in adjusting the portion and the type of food to its new situation, maintaining a suitable exercise routine and monitoring the body condition at check-ups. With this care, your pet will stay at its ideal weight. If you want to go deeper, we recommend our guide on obesity in dogs and cats.
Assess each case with your vet; the right treatment depends on each animal's age, weight, health status and history.
Frequently asked questions
Is sterilisation painful for my pet?
The surgery is performed under general anaesthesia, so the animal feels no pain during the procedure. Pain relief is prescribed for the recovery period, so that recovery is as comfortable as possible. By following your vet's instructions, the discomfort is mild and short-lived.
How long does recovery take?
Most dogs and cats recover their usual activity within a few days, although complete healing of the wound takes a little longer. During that period it is advisable to limit intense exercise and prevent the animal from licking the area. Your vet will tell you when to remove the sutures, if there are any.
Can I sterilise an adult or older animal?
Yes. Although some preventive benefits are greater when the procedure is performed early, it can also be carried out on adult or older animals, always after an assessment of their health status. In those cases, the prior evaluation becomes especially important to ensure safety.
Get your questions answered at Clínica Veterinaria Somo
The decision to neuter or spay your dog or cat should be made with good information and the advice of a professional who knows your animal. At Clínica Veterinaria Somo, in Cantabria, we assess each case individually and support you throughout the entire process, from the initial consultation to the recovery period.
If you would like to clear up your doubts or plan the procedure, book your appointment here or call us on 942 51 00 66. We will be delighted to help you care for the health and wellbeing of your best friend.
