Ilium Estromil

Injection

Indications
Synthetic prostaglandin for cattle & horses.

Pharmacology
ESTROMIL, a synthetic prostaglandin analogue is structurally related to Prostaglandin F2α(PGF2α). Each mL contains 263µg cloprostenol sodium equivalent to 250µg/mL cloprostenol.

ESTROMIL is a potent luteolytic agent, i.e. It causes functional and morphological regression of the corpus luteum (luteolysis). Luteolysis is usually followed by return to oestrus two to four days after treatment, and normal ovulation. Note: There is a refractory period of four to five days after ovulation when cattle are insensitive to the luteolytic effect of prostaglandins.

ESTROMIL has a good safety margin and does not impair fertility. No deleterious effects have been reported on the progeny conceived at the oestrus following treatment. In cattle, adverse reactions have not been seen at up to 80 times the effective recommended dose (550mg). The only clinically apparent effect was mild and transient diarrhoea.

Directions for use
Cattle: Single or repeat doses of 2mL i.m.

Effective treatment of:
1. Therapeutic suboestrus (or non-detected oestrus – NDO):
This condition occurs in heavy yielding cows, usually at peak lactation, which have normal ovarian cyclicity but in which behavioural manifestations of oestrus are either very mild, transient or absent.

Such animals can be treated with ESTROMIL following diagnosis of a corpus luteum by rectal palpation and then closely observed for oestrus. Those showing heat should be inseminated. Some animals may have been treated during the refractory period of the cycle and therefore will not respond. Animals showing heat should receive a further single injection 11 days after the first and be inseminated between 72 and 96 hours later.

Termination of normal but unwanted pregnancies:
Pregnancies can be terminated from one week after conception until the 150th day of gestation.
Before 100 days gestation, abortion can be induced rapidly and efficiently.
Between 100 and 150 days of gestation results are less reliable probably because a proportion of cattle may become progressively less dependent upon the corpus luteum for the maintenance of pregnancy. Abortion should not be induced after 150 days of gestation. Treated animals should be kept under supervision until expulsion of the foetus and the placental membranes is complete, as an occasional animal may develop metritis following abortion. Most cows will abort in 3-5 days, if an animal has not aborted by the 8th day, a second injection should be given.

Termination of abnormal pregnancy/removal of mummified foetus:
Death of the conceptus may be followed by its dehydration and degeneration. Induction of luteolysis at any stage of pregnancy will result in the expulsion of this mummified foetus from the uterus into the vagina. Manual removal from the vagina may be necessary. Normal cyclical activity should then follow.

Hydrops of the foetal membranes:
Pathological accumulation of placental fluids – hydramnios or hydrallantois – can cause several physiological complications and death. Surgical drainage is not usually successful in alleviating the condition. A single dose of ESTROMIL may be used to induce parturition in such cases; success has been achieved as early as the sixth month of pregnancy.

Chronic endometritis (Pyometra):
Damage to the reproductive tract at calving or post-partum retention of the placenta, frequently leads to infection and inflammation of the uterus, which is often resolved by local and systemic antibiotic treatment. However, under certain circumstances, a few weeks post-partum, the endometritis may have progressed until the uterus is very swollen, of a soft doughy consistency and full of purulent discharge. This is characterised by a lack of cyclical oestrus behaviour and the presence of a persistent corpus luteum. This condition can be successfully treated by induction of luteal regression. When necessary treatment may be repeated at 10-14 day intervals.

Induction of parturition: Induction of parturition should take place as close to the predicted calving date as possible and not more than 10 days before. Induction should not be attempted before day 270 of gestation, measured from the confirmed day of conception. All treated animals must receive adequate supervision. In common with all other methods of shortening the gestation period, a higher than usual incidence of retention of the foetal membranes is to be expected.
It is now recognised that there may be a reduced survival rate in calves born as a result of early induction. Any increased mortality is due to lack of viability as a result of immaturity rather than any effect from the prostaglandins.

Ovarian Luteal Cysts: Where cystic ovaries associated with persistent luteal tissue and absence of oestrus are diagnosed, ESTROMIL has proven effective in correcting the condition and bringing about a return of cycling. Accurate diagnosis is essential if completely satisfactory results are to be achieved.

2. Controlled breeding programmes in cattle
The luteolytic activity of ESTROMIL can be harnessed to control the breeding patterns of cattle. A variety of treatment regimes exist from which it is possible to choose the most appropriate for the characteristics of each particular individual, group or herd. ESTROMIL can be used to complement oestrus detection input or animals may be bred ‘on schedule’ during critical times of the breeding season, without reference to oestrus detection.

Use one of the programmes in Table 1

Table 1

Note:
• Best results obtained where heat detection is utilised. This is generally assisted by the use of tail paint.
• Identification of animals is important.
• Conception rate may be about 20% less if insemination is carried out en masse 72 hours after injection with no following insemination.
• ESTROMIL can also be used in systems which include other treatment regimes e.g. CIDR.

3. Dairy Herd
To control Oestrus in the individual animal giving better control of the calving index by allowing artificial insemination (A.I.) without oestrus detection. The number of cows culled as barren is consequently reduced.

To synchronise oestrus in groups of cows to promote management of the herd in groups of suitable size for feeding, A.I. and ‘drying off’. The chances of maintaining a strictly seasonal calving herd are improved and the number of barren cows at the end of the breeding program is reduced.

To permit the use of A.I. in dairy heifers which, in turn, allows the speeding up of the breeding programme, the use of a bull known to produce few dystocia problems, better control of heifer management, and ‘steaming up’ prior to calving.

4. Beef Herd
To facilitate the use of A.I. improving the progeny through the use of genetically superior bulls. The problems of oestrus detection are avoided and the labour involved in carrying out an A.I. programme is reduced by allowing groups of cattle to be presented instead of single animals.

To permit better management at conception and calving: The calving pattern is altered, resulting in greater average weight of calves at weaning. The peak calving period can be forecast more accurately in relation to other events in the farm calendar and there is an improved potential for ‘flushing’ cows prior to A.I.

Horses: Single dose i.m. 0.5mL - 1mL up to 400kg b.w. 1 - 2mL for 400kg bodyweight & above.

ESTROMIL is a potent luteolytic agent causing regression of the corpus luteum in MARES in a variety of circumstances. Luteolysis is usually followed by oestrus, appearing 2 - 4 days after treatment, with ovulation during the induced oestrus. This sequence of events is seen, for example, in mares treated with Estromil during dioestrus (the progestational) phase of the oestrus cycle, but it should be noted that there is a refractory period of 4 - 5 days after ovulation when mares are not responsive to the luteolytic action of prostaglandins.

ESTROMIL has a wide margin of safety and no deleterious effect on foals conceived and born as a result of mares being covered at the induced oestrus. This property of shortening the lifespan of the corpus luteum makes ESTROMIL of clinical value in:

Induction of Luteolysis following early foetal death and resorption: About 8 -10 percent of all mares which conceive lose the conceptus during the first 100 days of pregnancy. Persistence of the luteal function in the ovary precludes an early return to oestrus. Treatment before day 45 is recommended. After that time no response may be obtained due to the presence of circulating P.M.S.G.

Termination of Pseudopregnancy:
Some mares covered at normal oestrus and subsequently found to be empty (but not having lost or resorbed a conceptus) display clinical signs of pregnancy. These animals are said to be ‘pseudopregnant’.

Treatment of lactation anoestrus:
Failure of lactating mares to cycle again for several months after exhibiting and early ‘foal heat’ can be avoided in most cases.

Barren and maiden mares:
Some of these animals will be found on examination, to have a functional corpus luteum and are either suffering from abnormal persistence of luteal function or are simply failing to exhibit normal oestrus after 2-4 days, with ovulation occurring 8-12 days after treatment.

Nomination of time of service:
Mares may be brought into oestrus at will, simply as an aid to successful and economic management of stallions during the breeding season.

Presentation
Multidose vial comprising
10 x 2mL doses, 20mL pack,
50 x 2mL doses, 100mL pack.

Composition
Cloprostenol (as the
sodium salt) 250µg/mL.

Precautions
ESTROMIL can be absorbed through the skin and therefore, care should be taken when handling this product, particularly by women of child-bearing age and also by asthmatics. In case of accidental spillage on skin, wash immediately with water.

Prostaglandins of the F2α type may cause broncho-spasm in man. Should respiratory embarrassment result from accidental inhalation or injection, a rapid acting broncho-dilator e.g. isoprenaline or salbutamol by inhalation
is indicated

Avoid intravenous injection.

In horses adverse reactions including sweating, increased respiratory and cardiac rates, signs of abdominal discomfort, water diarrhoea and depression may occur when exceptionally high doses are given.
However adverse affects are usually mild and transient.

ESTROMIL should not be administered to:

Mares suffering from acute or sub-acute disorders of the gastrointestinal tract.

Mares suffering from acute or sub-acute respiratory disease. (This is a precautionary measure because in some species of animals, dosing with prostaglandins can result in acute respiratory distress.)

Pregnant mares, since luteolysis at some stages of gestation will result in loss of the foetus.

Withholding period
Milk: Nil.
Meat: Do not use less than 1 day prior to slaughter for human consumption.
Horses: Not to be used in horses intended for human consumption

Storage
Store below 25ºC (air conditioning). Protect from light

Registration
All states

APVMA Number
51716