It is also a good idea to join the relevant cat club for your breed. A breeder should be able to suggest a stud cat that is known to produce healthy offspring. Before being allowed to mate, your queen should be treated for worms, have received her routine vaccinations. Ask the owner of the stud cat for proof that it is also up to date with its vaccinations. If you let your cat out she will probably be mated before you know she is calling, but it is better not to allow your cat to have kittens until she is fully grown.
Some cats are sexually mature at an early age and can, if held back for too long, lose condition.
If your cat calls persistently when you do not think she is big enough to mate, consult your veterinary surgeon for advice. Your cat can have a hormone injection or tablets to prevent pregnancy before she is fully grown, but this may affect her future fertility and is not recommended by vets except in exceptional circumstances. Some breeds, especially Siamese and Burmese, will come into season at any time of the year. This varies between individuals and the oriental breeds, in particular, may cycle more frequent. A queen in season will become more noisy and affectionate than usual.