Lutalyse 12.5 mg/ml Solution for Injection for Cattle

The dose for all indicated use in cattle is 2 ml (25 mg dinoprost).
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 rubber stopper of the vial may be safely punctured up to 20 times. Otherwise,
automatic syringe equipment, or a suitable draw-off needle, should be used for the
100 ml vials to avoid excessive puncturing of the closure.
NOTES
1. Oestrus control in cycling cattle.
Individual cows or heifers treated during dioestrus will normally return to oestrus and
ovulate within two or four days after treatment. This may be employed to advantage
as an effective aid towards managing oestrus and breeding in individual animals.
2. Treatment of sub-oestrus (no visible oestrus) in cattle.
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 suckler 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.

Revised: May 2025
MA split from NI MA following AN: 00175/2025
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).
3. Induction of abortion in cattle.
Lutalyse may be used to terminate pregnancy in cattle 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 percentage 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.
4. Induction of parturition in 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.
5. Treatment of metritis or pyometra in cattle.
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 long standing.
6. Controlled breeding in cattle.
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.

Revised: May 2025
MA split from NI MA following AN: 00175/2025
Programme I
1. Inject 2 ml Lutalyse 12.5 mg/ml (25 mg dinoprost) intramuscularly;
2. Repeat the injection in 11 (10 to 12) days; then,
3. Inseminate 78 (75 to 80) hours after the second Lutalyse injection. No oestrus
detection or observation is required if animals were cycling normally when
injected.
This programme is recommended for most herds with successful A.I experience
where females are known to be cycling.
Programme II
1. Inject 2 ml Lutalyse 12.5 mg/ml (25 mg dinoprost) intramuscularly;
2. Repeat the injection in 11 (10 to 12) days; then,
3. Inseminate 72 (70 to 74) hours and 90 (88 to 96) hours after the second
Lutalyse injection. No oestrus detection or observation is required if animals
were cycling normally when injected.
Double insemination has demonstrated increased pregnancy rates in some herds.
Programme III
a
1. Inject 2 ml Lutalyse 12.5 mg/ml (25 mg dinoprost) intramuscularly;
2. Repeat the injection in 11 (10 to 12) days; then,
3. Inseminate upon detected oestrus.
Programme IV
a
1. Inject 2 ml Lutalyse 12.5 mg/ml (25 mg dinoprost) intramuscularly;
2. Inseminate upon detected oestrus.
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.
Programme V
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:

Revised: May 2025
MA split from NI MA following AN: 00175/2025
•
•
•
•
Alternatively:
•
•
•
observed oestrus if sooner.
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.
GENERAL NOTES
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:
1. Cattle must have a corpus luteum on the ovary of about five days or more of
age in order for Lutalyse to be luteolytic, i.e. they are healthy and are
undergoing normal oestrus cycles.
2. Semen of high fertility must be inseminated.
3. Semen must be inseminated properly.
4. Oestrus must be detected accurately if timed AI is not employed.
5. Physical facilities must be adequate to allow cattle handling without being
detrimental to the animal.
6. Nutritional status must be adequate prior to and during the breeding season
as this has a direct effect on conception and the initiation of oestrus in heifers
or return of oestrus cycles in cows following calving.