Both castration in the male cat and spaying in the female are major operations which need a general anaesthetic. Your cat must be fasted overnight before the operation to reduce the risk of problems on the operating table. Castrating male cats is a relatively straightforward operation and there is very little chance of anything going wrong. Spaying females is more difficult but it is one of the operations most frequently carried out by vets and any experienced vet will have done it many hundreds of times.

Both castration and spaying involve a single cut, into the belly of the female, to remove the ovaries and uterus (womb), or into the scrotum of the male dog to take out the testicles. Your cat should be ready to come home on the same day as surgery, as soon as the anaesthetic has worn off. If there are any complications, your vet might want to keep your cat in hospital overnight to keep an eye on them.