Neutering: when it is compulsory and what you need to know

For cats it is compulsory before six months of age. For dogs and other species, you decide with your vet. What to weigh up.

Cats: compulsory

Ley 7/2023 (the Animal Welfare Act) requires all cats to be neutered before six months of age, except those listed as breeding animals of a registered breeder (art. 26.i).

Dogs and other species

For dogs it is not required by law, but preventing them from breeding uncontrolled is (art. 26.d): only people listed in the Registro de Criadores (Breeders' Register) can breed. The ideal age for neutering depends on size, breed and sex, and there is no single answer. Talk to your vet about the pros and cons for your animal.

What people often ask

Will it put on weight? It may need fewer calories afterwards. Adjust its food with your vet and keep up the exercise.
Will its character change? Its personality does not change. Some behaviours linked to heat, such as marking or running off, usually decrease.
Is it a big operation? It is surgery under anaesthetic and needs a few days of care: rest and stopping it from licking the wound, with a cone collar or a recovery suit.