A decision that frequently causes owners to hesitate, neutering (males) and spaying (females) deserve informed reflection rather than a decision based solely on preconceived ideas, in either direction.

The documented health benefits

  • In females: significant reduction in the risk of mammary tumours (especially if the procedure takes place before the first heat), elimination of the risk of pyometra (a serious uterine infection)
  • In males: elimination of the risk of testicular cancer, reduced risk of prostatic hyperplasia

The behavioural effects, to be qualified

Contrary to a widespread belief, neutering/spaying does not systematically "calm down" a dog with a naturally energetic or difficult temperament — these traits stem more from genetics and upbringing than from sex hormones. The procedure can, however, reduce certain behaviours directly linked to reproduction (urine marking, roaming during heat, aggression between males).

Timing: a question to discuss with your vet

The optimal age for the procedure varies according to the dog's breed, size and sex — large breeds generally benefit from completing their bone growth before the procedure, a point to discuss precisely with your vet rather than following a single general rule.

The impact on metabolism

A neutered or spayed dog generally sees its metabolism slow down, which requires adjusting food portions to avoid weight gain (see our dedicated article on weight management) — a often-overlooked point that explains a significant share of the overweight cases observed after the procedure.

For the sport or working dog

The timing of the procedure deserves particular attention for dogs intended for sport or intensive work, as some studies suggest a potential impact on joint development depending on the age at which it is performed — a topic to raise specifically with a vet familiar with the needs of sport dogs.

An individual decision, not a universal rule

There is no universal answer as to whether or when to neuter or spay — the decision deserves to be made on a case-by-case basis, taking into account the breed, lifestyle, goals (sport, breeding, companionship) and the advice of a trusted vet.

Also available in English: nutrition and dietary supplements: when and why to consider them, the most common injuries in sport and outdoor dogs and the raised dog bed: comfort, hygiene and durability. More translations are added over time.