Megestrol acetate is a potent progestagen with marked anti-oestrogenic properties. It is recommended for administration by the oral route in bitches for the postponement or prevention of oestrus and the treatment of hypersexuality which may be manifest as undesirable behaviour in male dogs.

In cats it is recommended for prevention or postponement of oestrus and the treatment of miliary dermatitis and eosinophilic granulomata.

Ovarid Tablets may be used to postpone an anticipated oestrus. Following the recommended course it is not possible to state when the next oestrus period will occur, with any degree of accuracy, as this will depend on the stage of an-oestrus when the tablets were administered. It is most likely, however, that it will appear some three months later. It is unlikely that oestrus will be delayed by more than six months.

When the tablets are used by the recommended method for the prevention of oestrus, the signs of pro-oestrus usually disappear in two to three days and the subsequent oestrus normally occurs four to six weeks earlier than would have been the case had medication not been given.

Oestrus can be prevented or postponed by selecting an appropriate dose regime. The occurrence of the next oestrus following treatment may be variable because the cat is seasonally polyoestrus and ovulation does not occur spontaneously.

However, the next call after a prevention course given during the breeding season will probably occur a few days later than normally expected – on average about four weeks after the last dose is given. Queens given a correctly timed postponement course will not call whilst they are receiving the tablets.

Field experience with Ovarid has shown it to be very successful in the treatment of miliary eczema. A clinical response can be expected in most cases within the first few days of commencing treatment.

Clinical experience has shown that Ovarid can be beneficial in this condition.

Trials have shown that Ovarid is an effective treatment in 75% of dogs exhibiting the following undesirable behaviour: