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SucroMate Equine

This page contains information on SucroMate Equine for veterinary use.
The information provided typically includes the following:
  • SucroMate Equine Indications
  • Warnings and cautions for SucroMate Equine
  • Direction and dosage information for SucroMate Equine

SucroMate Equine

This treatment applies to the following species:
Company: Thorn BioScience

Sterile Suspension





SucroMate Equine Caution

Federal law restricts this drug to use by or on the order of a licensed veterinarian.


SucroMate™ Equine is a sterile, synthetic gonadotropin-releasing hormone (GnRH) analog (deslorelin acetate) suspension. SucroMate™ Equine is a sustained release formulation that forms an in situ gel upon intramuscular injection. Deslorelin acetate is [(6-D-tryptophan-9-(N-ethyl-L-prolinamide)-10-deglycinamide)] GnRH. The molecular weight is 1282.6.


The deslorelin acetate structural formula is:

[(6-D-tryptophan-9-(N-ethyl-L-prolinamide)-10-deglycinamide)] GnRH

Each mL contains 1.8 mg/mL deslorelin acetate (1.7 mg/mL deslorelin) for injection as a sterile suspension in sucrose acetate isobutyrate/propylene carbonate (70:30 wt:wt). Ten doses per vial.


SucroMate™ Equine is indicated for inducing ovulation within 48 hours of treatment in cyclic estrous mares with an ovarian follicle between 30 and 40 mm in diameter.

Dosage and Administration

Shake well before use. Administer 1 mL (one dose) per estrus cycle, 48 hours prior to desired ovulation. Verify that the mare is in estrus and has at least one ovarian follicle between 30 and 40 mm in diameter.

SucroMate™ Equine is a suspension of deslorelin and settling will occur over time. Warm the product for 2 minutes by rolling the vial between the palms (to reach room temperature), or allow the vial to sit for 30 minutes at room temperature prior to administration. Shake the vial vigorously for 1 minute before use. Administer a 1 mL intramuscular injection into the thick musculature of the neck.

Prior to administration, it should be determined by rectal palpation and/or ultrasonography that the cyclic estrous mare has an ovarian follicle greater than 30 mm in diameter. Effectiveness is contingent upon accurate diagnosis of estrus and detection of a developing follicle between 30 and 40 mm in diameter. Only 1 mL should be administered per mare during a given estrus.


SucroMate™ Equine is contraindicated in horses known to be hypersensitive to deslorelin acetate.


For use in horses (estrous mares) only. Do not use in horses intended for human consumption. For intramuscular (IM) use only. Do not administer intravascularly. Not for use in humans. Keep this and all drugs out of reach of children.


Pregnant women and women of childbearing age should exercise caution when handling this product. Accidental administration may lead to a disruption of the menstrual cycle. Direct contact with the skin should be avoided. If exposure occurs, contact areas should be washed immediately with alcohol followed by soap and water, as this product is insoluble in water. In case of accidental human injection, consult a physician immediately.


The use of GnRH analogs in cycling mares has been associated with prolonged interovulatory intervals. SucroMate™ Equine has not been evaluated in mares less than 3 years of age.

Adverse Reactions

Injection site swelling was observed following the administration of SucroMate™ Equine (deslorelin acetate) during the effectiveness and safety studies; all injection site swellings resolved within 5 days, and 7 - 14 days, respectively.

For technical assistance or to report a suspected adverse reaction call 1-800-456-1403.

Clinical Pharmacology

Deslorelin induces ovulation by increasing the levels of endogenous luteinizing hormone. SucroMate™ Equine (deslorelin acetate) has been shown to induce ovulation within 48 hours of treatment in 78% of mares with a developing follicle greater than 30 mm in diameter. This product is intended to optimize breeding management through induction of ovulation within 48 hours.


Two hundred eighty three (283) mares, ranging in age from 2 to 20 years (mean 10.6 years) of age randomly received either SucroMate™ Equine or placebo and were evaluated for field safety under actual conditions of use. A total of 191 mares (97 placebo and 94 mares in the SucroMate™ Equine group) were evaluated for effectiveness. Breeds included Standardbreds, Thoroughbreds, Quarter Horses and Paints. Mares were evaluated for up to 3 cycles to determine if SucroMate™ Equine induced ovulation in cyclic mares, and to determine the effects on the interovulatory interval, pregnancy rate and general health characteristics of the resultant foals.

The proportion of mares ovulating within 48 hours of treatment was significantly higher in the SucroMate™ Equine group as compared to the placebo group (see Table 1).

Table 1. Percentage of Mares Ovulating Within 48 Hours of Treatment

(Yes = ovulated / No = did not ovulate)


Placebo (1.0 mL)

SucroMate™ Equine (1.0 mL)

P value

1st Cycle




Number of mares treated





23 (24%)

68 (72%)

p = 0.000*


73 (75%)

25 (27%)


Not determined

1 (1%)

1 (1%)


2nd Cycle




Number of mares treated





9 (36%)

29 (83%)

p = 0.000*


16 (64%)

6 (17%)


3rd Cycle




Number of mares treated





3 (33%)

12 (92%)

p = 0.006*


6 (67%)

0 (0%)


Not determined

0 (0%)

1 (8%)


Average % ovulating within 48 hours after treatment in any cycle




*statistically significant

Following treatment in each of three estrus cycles, the mean hours to ovulation was reduced in the SucroMate™ Equine treated group compared to the placebo group (See Table 2).

Table 2. Mean Hours to Ovulation


Placebo (1.0 mL)

SucroMate™ Equine (1.0 mL)

P value

1st Cycle

91.8 (n=96)

65.1 (n=90)

p = 0.019*

2nd Cycle

83.0 (n=24)

56.2 (n=35)

p = 0.099

3rd Cycle

85.3 (n=9)

41.0 (n=12)

p = 0.153

*statistically significant

The interovulatory interval was calculated between cycles for all mares that did not become pregnant in the previous cycle. There was no significant difference in the length of interovulatory intervals between the SucroMate™ Equine treated group and the placebo-treated mares as represented in Table 3.

Table 3. Mean Interovulatory Interval (days)


Placebo (1.0 mL)

SucroMate™ Equine (1.0 mL)

P value

Cycles 1-2

26.1 (n=27)

22.3 (n=32)

p = 0.182

Cycles 2-3

21.3 (n=9)

18.5 (n=11)

p = 0.336

Cycles 3-4

13.0 (n=1)

18.0 (n=1)


Twins were detected in 8 placebo mares and 2 SucroMate™ Equine mares. The nursing behavior, mobility and general health of the live foals were similar for foals from mares in the SucroMate™ Equine and placebo groups. See Table 4 for a summary of the foaling and foal assessment data.

Table 4. Foaling and Foal Assessment Data*


Treatment Group



SucroMate™ Equine

Mares confirmed pregnant in 1999 breeding season out of total # of mares per group % (n/N)

83% (118/143)

81% (114/140)

Mares confirmed to have a live foal out of # of pregnant mares % (n/N)

94% (111/118)

84% (96/114)

Mares confirmed to have a stillbirth out of # of pregnant mares % (n/N)

0% (0/118)

3.0% (3/114)

72 Hour-General Health Foal Assessment % (n/N)


80% (89/111)

79% (76/96)


16% (18/111)

20% (19/96)

Not Satisfactory

2% (2/111)

2% (2/96)

4 Week-General Health Foal Assessment % (n/N)


34% (38/111)

36% (35/96)

Not Assessed

66% (73/111)

67% (64/96)

*data could not be obtained on all mares

When administered to cyclic, estrous mares with a pre-ovulatory follicle between 30 mm and 40 mm in diameter, a single, 1 mL injection of SucroMate™ Equine (1.8 mg of deslorelin acetate/mL) resulted in ovulation within 48 hours of treatment in 78% of treated mares. The length of the inter-ovulatory interval between cycles was not altered. The pregnancy rate of the treated mares was similar to the placebo mares.

Animal Safety: In the target animal safety study, 32 reproductively sound, mixed breed mares, ranging in age from 3-15 years were administered 1X (1 mL), 3X (3 mL) and 5X (5 mL) the recommended 1.8 mg dose of SucroMate™ Equine for three consecutive cycles. Treatment with SucroMate™ Equine at all doses reduced the mean hours to ovulation during all three treatment cycles compared to the placebo group. Of the sixty-five treatment experiences for the SucroMate™ Equine treated mares across the three cycles 55 (84.6%) were followed by ovulation within 48 hours compared to five of twenty-three (21.7%) for placebo mares. There was no statistically significant effect on the length of estrus at any dose level.

Some mares in all SucroMate™ Equine treatment groups exhibited mild to moderate swelling at the injection site six hours post-injection during all three treatment cycles. Sensitivity to touch was more frequent in the 5X dose group at Day 1 post-treatment in Cycle 1, and at Days 2 and 4 post-treatment in Cycle 2, and in the 3X group at Day 1 post-treatment in Cycle 1. All injection site reactions in the 1X treated mares resolved by Day 3 post-treatment. Two mares, one 3X mare and one 5X mare, had swelling and hardness noted at injection sites at Day 7 post-treatment. The incidence of injection site reactions for the placebo, 1X, 3X and 5X groups was 37%, 75%, 50%, and 87%, respectively.

The LH concentrations in the SucroMate™ Equine treated groups in all three cycles exhibited an expected surge following treatment and prior to ovulation, followed by lower concentrations during the midluteal phase, with a gradual return to pretreatment levels.

The mean inter-ovulatory interval in the SucroMate™ Equine groups ranged from 17.8 - 23 days compared to 21 - 23.5 days in the placebo group.

All mares that ovulated after the 3rd treatment with SucroMate™ Equine or placebo were bred. These mares were bred until they became pregnant (not to exceed three cycles). In the placebo group, seven mares ovulated after the 3rd treatment and were bred. Six of the seven mares became pregnant (85.7%). In the 1X group, six mares ovulated after the 3rd treatment and were bred. All six became pregnant (100%). In the 3X group, eight mares ovulated after the 3rd treatment and were bred. Six of the eight mares became pregnant (75%). In the 5X group, five mares ovulated after the 3rd treatment and all became pregnant (100%).

There were no significant differences across the treatment groups in terms of time to pregnancy or the number and proportion of mares that became pregnant after three consecutive SucroMate™ Equine injections.

In a separate dose tolerance study mares received a single IM injection of placebo (8 mares) or SucroMate™ Equine at 10X the recommended of 1.8 mg dose (8 mares). One SucroMate™ Equine10X mare exhibited moderate tremors and hives at 6 hours post-treatment.


Store refrigerated at 2-8°C.

How Supplied

One (1) 10 mL vial (10 doses) per vial

NADA 141-319, Approved by FDA.

NDC NUMBER: 51330-167-10

Developed and Manufactured by: Thorn BioScience LLC, Louisville, KY 40204 USA

To report suspected adverse reactions or to obtain a copy of the Material Data Safety Sheet (MSDS), or for technical assistance call 1-800-456-1403 or


CPN: 15450000

Every effort has been made to ensure the accuracy of the SucroMate Equine information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the US product label or package insert.

Copyright © 2020 Animalytix LLC. Updated: 2020-10-21