Answer: Unless you wish to breed from your cat, the long term solution would be to have her spayed. However, this operation should not be done whilst the cat is actually calling because the inevitable bleeding is more difficult to control and the operation carries more risk. This appears to be due to effect of oestrogen on blood clothing.
To stop calling that is currently taking place, particularly if it has been going on for some time with no sign of abating (as it may Siamese especially), ovulation can be induced artificially. This is achieved by carefully inserting a sterile, smooth glass rod or a moistened cotton bud into the vagina for about three-eights of an inch. The cat should be restrained on a table by a helper who is holding it is scruff. Then the inserted rod or cotton bud should be gently rotated, and moved backwards and forwards a little. It is quite normal for the female to cry out and afterwards roll, rub and lick herself. If ovulation is successfully stimulated, the cat will go off heat in one to two days (as is usual) and then will follow a period of pseudo-pregnancy lasting for approximately forty days. Very rarely this period terminates in mammary gland enlargement and maternal behaviour.
The some effect is sometimes achieved by breeders using a vasectomized tom cats. Such a male cats retains all his normal sexual behaviour but will not implant any sperms, so that mating again will result in a pseudo-pregnancy. Nevertheless, for at least forty-eight hours after ovulation has been induced in these ways (in fact until all signs of oestrous have disappeared), care must be taken to avoid a normal mating or the cat may become pregnant.
