Some females will not come into heat. Hormones can be used to do this if no heat is evident near the end of the breeding season. Work in Norway suggests the following. Give subcutaneous injections (under the skin) daily of 100 IU pregnant mare serum gonadotrophin (PMSG) for up to five days. On the first day of heat, give one injection of 200 IU of human chorionic gonadotrophin (HCG). This treatment resulted in 100 percent pregnancies.
Caution is necessary, as a second Norway experiment shows seven pregnant animals were given several shots of 200 IU of HCG during the last half of pregnancy. Five had prolonged pregnancies of which three were induced to deliver with steroids. Caesarian sections on the other two revealed degenerate fetuses.
Therefore, care must be taken not to use those hormones on animals which may be pregnant.