Reg. No.

5 mg tablets: 83/588 (Act 101/1965)

20 mg tablets: 83/589 (Act 101/1965)

Each tablet contains megestrol acetate BVetC in a dried yeast base. Two strengths are available: 20 mg tablets and 5 mg tablets.

Pharmacological action:
Megestrol acetate is a potent progestagen with marked anti-oestrogenic properties. 

Indications:

It is recommended for administration by the oral route in bitches for the postponement or prevention of oestrus and the treatment of false-pregnancy and oestrogen-dependent mammary tumours.

It is recommended for the treatment of hypersexuality which may manifest as undesirable behaviour.

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

Postponement of oestrus (Bitches): Ovarid tablets may be used to postpone an anticipated oestrus. Following the recommended course it is not possible to state, with any degree of accuracy, when the next oestrous period will occur 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.

Extended postponement of oestrus (Bitches): Experiments have shown that oestrus can be postponed safely for longer periods of time by an extended dosage regime. In this case, a full forty day postponement course of Ovarid should be given starting in an oestrus, preferably fourteen, but at least seven days before the effect is required. At the end of that period, treatment may be continued on a twice-weekly basis for as long as it is desired to postpone oestrus but not exceeding four months. Oestrus will not occur whilst bitches are receiving the tablets, but, as is the case with the shorter dosage regime, it is not possible to say exactly when oestrus will occur after withdrawal of the tablets. In the majority of bitches, however, this interval is likely to be about two to three months.

Prevention of oestrus (suppression of heat) (Bitches): 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.

Treatment of false-pregnancy (Bitches): Ovarid tablets will, in most cases, alleviate the physical and nervous signs of false pregnancy within three days.

In a small percentage of treated cases the signs of false-pregnancy may recur some three to six weeks later. This incidence can be minimised by commencing treatment immediately the signs are seen. Treatment with Ovarid is less effective in cases which have recurred. Ovarid should not be used in cases which have been recently treated with oestrogens.

Oestrus control in cats: 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.

Miliary eczema in cats: In the past, corticosteroids and sex hormones have been used in the treatment of miliary eczema but the results have been inconsistent. Field experience with megestrol acetate, however, has shown it to be very successful, a response being noticed in most cases within the first few days of commencing treatment.

Eosinophilic granuloma (‘rodent ulcer’) in cats: Some veterinary surgeons have found that Ovarid can be beneficial in this condition.

Oestrogen-dependent mammary tumours in bitches: It has been found that Ovarid will reduce the size of these tumours. It has also been noted that the blood supply to the neoplasm is often reduced, it becomes more circumscribed and thus surgical removal can be more easily accomplished.

Undesirable behaviour in dogs: Trials have shown that Ovarid is effective in treating dogs exhibiting the following undesirable behaviour:

Aggression – either dominant or submissive (fear-induced)

Mounting

Territory marking by urination

Roaming

Excitability

Destructiveness

Contra-indications and warnings:

It must be remembered that progestagens, like other synthetic hormones, should always be used with care. This is particularly so in bitches treated at their first oestrus. Owners should be advised that this class of bitch and a small proportion of others which have abnormal oestrus cycles may show excessive libido or oestrus and may return earlier than expected because of difficulties which may be encountered with the timing of administration. Apart from these considerations experience has shown that, when used correctly, Ovarid tablets do not produce undesirable side-effects since oral administration allows the duration of effect to be more accurately controlled than is the case with depot injections.

In the prevention of oestrus in bitches, the timing of administration is of great importance if the best results are to be obtained. If Ovarid tablets are given once ovulation has occurred, they may aid conception.

Ovarid is not recommended in diabetic animals.

Occasionally, lethargy and increased appetite with consequent weight gain may be seen in treated animals.

Very occasionally, following the long-term use of megestrol acetate in cats to prevent the recurrence of miliary eczema, mammary hypertrophy may occur. This effect is quite distinct from mammary neoplasia and may regress on cessation of dosing. In such cases medication should be withdrawn.

Male dogs intended for breeding should not be treated with Ovarid. 

Dosage and directions for use:

Postponement of oestrus (Bitches)

a)    Normal dosage regimen: 0,5 mg/kg daily for a maximum period of forty days. The course of tablets should be commenced preferably fourteen but at least seven days before the effect is required. A series of postponement courses may be given provided the bitch is not medicated more than twice in any twelve month period.

b)    Extended dosage regimen: 0,1 – 0,2 mg/kg twice weekly for a maximum period of four months following a 40 day course as described above. Bitches should be allowed to have a normal unmedicated oestrus before this course is repeated.

Prevention of oestrus (suppresion of heat) (Bitches): The course of tablets should be commenced at the onset of pro-oestrus as indicated by the presence of both haemorrhage and vulval swelling. The stage of the oestrus cycle may be confirmed by the examination of vaginal smears.

a)        Normal dosage regimen: 2 mg/kg daily for eight days.

b)        Extended dosage regimen: 2 mg/kg for four days followed by 0,5 mg/kg for sixteen days.

The use of this prolonged prevention course is advised in first season bitches, and may also be beneficial in bitches with a history of false pregnancy. In some cases where other abnormalities of the oestrus cycle are known to occur and when the animal to be medicated is housed with other bitches.

Treatment of false pregnancy: 2 mg/kg daily for five to eight days commencing when signs of false pregnancy are first seen.

Oestrus control in cats:

i)          Postponement of oestrus – Dosage can commence in di-oestrus (the short period of sexual inactivity between ‘calls’ during the breeding season) or in anoestrus (the non-breeding season).

a)      If dosing is started in di-oestrus – 2,5 mg/cat daily for up to two months.

b)      If dosing is started in an-oestrus – 2,5 mg/cat once weekly for up to eighteen months.

ii)    Prevention of oestrus – 5 mg per cat daily for three days commencing as soon as the signs of ‘calling’ are seen.

Treatment of miliary eczema (miliary dematitis) and eosinophilic granuloma (‘rodent ulcer’) in cats: The recommended dosage is 2,5 to 5 mg per cat every two to three days until the lesions begin to regress, then once weekly until a satisfactory response is obtained.  In some cases it may be necessary to give a maintenance dosage of 2,5 mg per cat weekly or fortnightly to prevent recurrence of the condition. Alternatively, repeat courses of treatment may be given as required.

Oestrogen-dependent mammary tumours in bitches: The following dosage regimes have been used:

i)          2 mg/kg daily for ten days, or

ii)         2 mg/kg daily for five days, followed by 0,5 to 1 mg/kg daily for a further ten days.

Undesirable behaviour in dogs: The dosage should be adjusted according to response and the following is offered as a guide:

In a minority of animals, it may be necessary to prescribe a low maintenance dose on a once weekly basis or to give repeat short courses of medication as required.

Further information:

Experience has shown that bitches conceive normally at the heat following the withdrawal of megestrol acetate. Ovarid can be safely given to bitches to prevent the oestrus which occurs after cessation of dosing with a long or short term postponement course.

In breeding queens it is advisable that mating should be allowed at the second or subsequent ‘call’ rather than the first ‘call’ after cessation of dosing.

Side-effects and special precautions:

There are no known side-effects.

Use before the expiry date given on the package.

Known symptoms of overdosage and its treatment:

There are no known, acute, symptoms of overdosage – see ‘Contra-indications’ and ‘Warnings’.

Conditions of registration:
Will be advertised to the veterinary profession only. 

Identification:
Buff coloured, slightly speckled, biconvex, uncoated tablets with a breakline on one surface.

Presentation:
40 x 5 mg tablets.
40 x 20 mg tablets.

Storage instructions:
Store at room temperature (below 25 °C). Keep out of reach of children and uninformed persons.

Registration holders:

Schering-Plough Animal Health
Co. Reg. No. 1934/005207/07