A clear sterile aqueous solution for injection. Lutalyse contains dinoprost 5 mg/ml present as 6.71 mg/ml of dinoprost tromethamine (THAM salt) with 1.65% benzyl alcohol as preservative. Dinoprost is the synthetic, naturally occurring prostaglandin F2α (PGF2α).

Lutalyse is indicated for its luteolytic and/or oxytocic effect in cattle, horses and pigs.

The indications for use are:

Individual cows or heifers treated during dioestrus will normally return to oestrus and ovulate within two to four days after treatment.

Mares treated during dioestrus will normally return to oestrus within two to four days and ovulate 8 to 10 days after treatment.

This may be employed to advantage as an effective aid towards managing oestrus and breeding in individual animals. (Note: Administration of Lutalyse to cattle and horses within four days after oestrus is unlikely to result in luteolysis of the corpus luteum. Administration within 48 hours before onset of the next oestrus may not influence the timing of the oestrus after treatment.)

Individual cattle may have normal cyclical ovarian activity, without detectable behavioural oestrus; this occurs most frequently in the winter months, at peak lactation in high producing dairy cows and in suckle beef cows. If a corpus luteum is present and ovulation has not occurred in the previous four days, administration of Lutalyse will result in corpus luteum regression followed by return to oestrus and ovulation.

Breeding of cattle treated with Lutalyse for the above indication may be by natural service, artificial insemination at the usual time in relation to observed oestrus, or by fixed time insemination (78 hours or 72 and 90 hours post-treatment).

In extended dioestrus in mares there is failure to exhibit regular oestrus cycles as distinct from true anoestrus. Many mares described as anoestrual during the breeding season have serum progesterone levels consistent with the presence of a functional corpus luteum.

A proportion of `barren', maiden and lactating mares do not exhibit regular oestrus cycles and may be in extended dioestrus. Following abortion, early foetal death and resorption, or as a result of `pseudo-pregnancy' there may be serum progesterone levels consistent with a functional corpus luteum.

Treatment of such mares with Lutalyse usually results in regression of the corpus luteum followed by oestrus and/or ovulation.

Lutalyse may be used to terminate pregnancy in cattle and mares through its luteolytic effect during those stages of pregnancy in which the corpus luteum is sensitive to its action and in which maintenance of pregnancy is dependent upon the corpus luteum as the sole source of progesterone.

Stage of gestation in cattle is an important factor influencing response. The percentage of animals responding to a single intramuscular injection decreases as the gestation period increases. Approximate percentages responding are 90% within the first 100 days of gestation, 60% within 101–150 days of gestation and 40% in animals beyond 150 days of gestation. In the early stages of gestation, abortion will usually occur within one week, but as gestation length increases, the period to abortion following injection may also increase. In mares up to day 35 of pregnancy luteal regression with Lutalyse will induce abortion; response to treatment between days 40 and 90 of gestation is less predictable, possibly due to PMSG secretion from the endometrial cups rendering the corpus luteum refractory to the luteolytic effect of Lutalyse. Between days 90 and 120 of pregnancy luteal regression may lead to abortion.

Cattle: Lutalyse has been used to induce parturition on or after day 270 of gestation. The interval from administration to parturition is one to eight days (average three days). Induction of parturition in cattle is indicated where there is a risk of oversize calves or where early parturition is desired. In addition, induction is indicated where pregnancies are complicated by miscellaneous conditions such as mummified or macerated foetuses, hydrops amnii, hydroallantois, etc. Lutalyse is indicated for expulsion of a dead foetus.

Pigs: Lutalyse may be used to induce parturition in pigs within 3 days of the normal predicted farrowing date. Response to treatment by individual animals varies within a range of 24–36 hours from administration to parturition. This can be advantageously employed to control the time of farrowing in sows and gilts in late gestation. Treatment earlier than 3 days prior to predicted farrowing date may produce weak piglets resulting in reduced survival. It is recommended that treatment be given in the early morning following feeding. A lack of response has been noted in a small proportion of pigs, the specific reason for which has not yet been determined.

In the cow chronic metritis frequently occurs as a sequel to an acute or sub-acute endometritis in the first two or three weeks post-partum; typically, there is an intermittent purulent or mucopurulent discharge. Pyometra is characterised by the retention of purulent fluid within the uterus.

Luteal regression through the administration of Lutalyse is followed by oestrus, during which the uterine environment is relatively unfavourable to the bacteria involved in the infection. Treatment may have to be repeated after 10–12 days where the condition is longstanding.

Lutalyse is indicated for its luteolytic effect in cattle. This luteolytic effect can be utilised to control the timing of oestrus in cycling cattle that have a corpus luteum. For normally-cycling cows, at least 35 days after calving, the identified activity of Lutalyse permits a wide range of oestrus control programmes.

This programme is recommended for most herds with successful A.I experience where females are known to be cycling.

Double insemination has demonstrated increased pregnancy rates in some herds.

a If it is unknown whether most animals to be treated are cycling, Programmes III and IV calling for oestrus detection should be followed rather than Programmes I and II calling for timed insemination. A 'clean-up bull' may be used following any Lutalyse programme, or the service may be repeated at the next oestrus, one cycle later, in animals that did not conceive at first service.

Practical application of these programmes will vary depending upon many factors, and in many cases these programmes may be altered to meet the requirements of the specific operation. For example, some veterinary surgeons may wish to design their own programmes for specific situations and schedules. The activity of Lutalyse may be easily adapted for such individualised approach. These changes should be carefully evaluated to ensure that they do not detrimentally affect the success of the breeding programme.

Lutalyse may be used as part of a fixed time artificial insemination protocol to synchronise ovulation for normally-cycling dairy cows at any stage of lactation. The following protocols have been commonly reported in the literature:

Alternatively:

To maximise conception rates of cows to be treated, the ovarian status should be determined and regular cyclic ovarian activity confirmed. Optimal results will be achieved in healthy normally-cycling cows.

PGF2α has a stimulating effect on uterine contractions, leading to better post-partum evacuation of the uterus. Field clinical trials in herds with reproductive problems confirmed that treatment with Lutalyse resulted in a more rapid return to oestrus and fertile service after farrowing.

A single injection of the recommended dose of dinoprost activity is luteolytic provided a functional corpus luteum is present. Administer by intramuscular injection. Full aseptic precautions must be taken. Use a sterile syringe and needle and make the injection through an area of clean dry skin. Care should be taken to avoid injection through wet or dirty areas of skin.

The dose for all indicated uses in cattle is 5 ml Lutalyse (25 mg dinoprost)

The dose for all indicated uses in mares is 1 ml Lutalyse (5 mg dinoprost)

1. Induction of parturition: 2 ml Lutalyse (10 mg dinoprost) within 3 days of expected parturition.

2. Use post-partum: 2 ml Lutalyse (10 mg dinoprost) 24 to 48 hours after parturition.

Prostaglandins of the F2α type can be absorbed through the skin and may cause bronchospasm or miscarriage.

Care should be taken when handling the product to avoid self-injection or skin contact.

Women of child-bearing age, asthmatics and persons with bronchial or other respiratory problems should avoid contact with, or wear disposable plastic gloves when administering the product.

Accidental spillage on the skin should be washed off immediately with soap and water. Wash hands after use.

Cattle: Localised post injection bacterial infections that may become generalized have been reported. Aggressive antibiotic therapy should be employed at the first sign of infection. Careful aseptic techniques should be employed to decrease the possibility of post injection bacterial infections.

Cattle (milk): zero hours.

Cattle (meat & offal): 2 days.

Pig (meat & offal): 1 day.

Horses: not to be used in horses intended for human consumption.

Treated horses may never be slaughtered for human consumption.

The horse must have been declared as not intended for human consumption under national horse passport legislation.

Not to be used in horses intended for human consumption.

Treated horses may never be slaughtered for human consumption.

The horse passport must have been declared as not intended for human consumption under national horse passport legislation.

Animals should not be treated if they suffer from either acute or sub-acute disorders of the vascular system, gastro-intestinal tract or respiratory system.

Contra-indicated when abortion or parturition is not intended.

Pregnancy status should be determined prior to injection since Lutalyse has been demonstrated to result in abortion or parturition induction when administered at sufficiently high doses to many animal species.

Do not administer by the intravenous route.

Lutalyse is ineffective when administered prior to day five after ovulation.

If pregnant, the unlikely possibility of uterine rupture should be borne in mind, especially if cervical dilation does not occur.

Induction of parturition in pigs earlier than 72 hours prior to predicted farrowing date may result in reduced piglet viability.

Cattle: The most frequently observed side-effect is increased rectal temperature at a 5 × or 10× overdose. However, rectal temperature changes have been transient in all cases observed and have not been detrimental to the animal. Limited salivation has been seen in some instances.

Horses: The most frequently observed side-effects are sweating and decreased rectal temperature. However, these have been transient in all cases observed and have not been detrimental to the animal. Other reactions seen have been increase in heart rate, increase in respiration rate, some abdominal discomfort, locomotor incoordination and lying down. These effects are usually seen within 15 minutes of injection and disappear within one hour. Mares usually continue to eat during the period of expression of side-effects.

Pigs: Transient side-effects consisting of increased body temperature, increased respiratory rate, increased salivation, stimulation of defaecation and urination, flushing of the skin and restlessness (arching of back, pawing, and rubbing and gnawing the crate) occur occasionally following the administration of dinoprost in pregnant sows and gilts. These effects tend to parallel the signs exhibited by sows prior to normal parturition, only they appear to be condensed in time. These effects are usually seen within 15 minutes of injection and disappear within one hour.

Do not store above 25°C.

Avoid the introduction of contamination during use. Should apparent growth or discolouration occur, the product should be discarded. Following withdrawal of the first dose, the product should be used within 28 days. Discard unused material.

Dispose of any unused product and empty containers in accordance with guidance from your local waste regulation agency.

Keep out of the sight and reach of children.

For animal treatment only.

Lutalyse is supplied in 30 ml vials and packs of 5 x 10 ml vials. Not all pack sizes may be marketed.

Many factors contribute to the success and failure of reproduction management, and these are important when the time of breeding is to be regulated with Lutalyse. Some of these factors are: