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Fertagyl 2 (Canada)

This page contains information on Fertagyl 2 for veterinary use.
The information provided typically includes the following:
  • Fertagyl 2 Indications
  • Warnings and cautions for Fertagyl 2
  • Direction and dosage information for Fertagyl 2

Fertagyl 2

This treatment applies to the following species:
Company: Merck Animal Health

Gonadorelin injectable solution


DIN 02316072

Veterinary Use Only

Description: Gonadorelin is a decapeptide composed of the sequence of amino acids: 5-oxoPro-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2. It has a molecular weight of 1182.32 g/mol and empirical formula of C55 H75 N17 O13. The molecular formula of its acetate is C55H75N17O13 • C2H4O2 with a molecular weight of 1242.3 g/mol. Gonadorelin acetate (45 µg/mL) is considered to be pharmaceutically equivalent to gonadorelin diacetate tetrahydrate (50 µg/mL) as they are both equivalent to 43 µg/mL of gonadorelin.

Gonadorelin is the hypothalamic releasing factor responsible for the release of gonadotropins (e.g., LH, FSH) from the anterior pituitary. Synthetic gonadorelin is physiologically and chemically identical to the endogenous bovine hypothalamic releasing factor.

Each mL contains:

Active Ingredients: 45 µg gonadorelin acetate, (Ph. Eur.) equivalent to 43 µg gonadorelin.

Preservatives: 9 mg benzyl alcohol.

Non-medicinal ingredients: 7.47 mg sodium chloride. The pH is adjusted with sodium phosphate (monobasic and dibasic).

Indications: Fertagyl® 2 is a hormone indicated for the treatment of ovarian follicular cysts and reproductive synchrony in dairy cattle.

Ovarian cysts are non-ovulated follicles with incomplete luteinisation which result in nymphomania or irregular estrus.

Historically, cystic ovaries have responded to an exogenous source of luteinizing hormone (LH) such as human chorionic gonadotropin. Fertagyl® 2 initiates the release of endogenous LH to cause ovulation and luteinisation. The average time to response is 21 days.

Dosage and Administration:

The use of a draw-off needle is recommended with the 100 mL vial.

Cystic ovaries:

The recommended dosage of Fertagyl® 2 is 2 mL per cow as a single intramuscular injection.

Reproductive synchrony:

Fertagyl (gonadorelin injectable solution) is indicated for use with Estrumate (cloprostenol injection USP) to synchronize estrous cycles to allow for fixed-time artificial insemination (FTAI) in lactating dairy cattle. The recommended intramuscular dosage of Fertagyl 2 is 86 µg/cow (2 mL; equivalent to 100 µg gonadorelin diacetate tetrahydrate/cow), used in reproductive synchrony programs similar to the following:

● Day 0: Administer the first Fertagyl 2 injection (2 mL)

● Day 6-8: Administer 2 mL of Estrumate (500 µg cloprostenol)

● Day 8-11: Administer the second Fertagyl 2 injection (2mL) 30 to 72 hours after the Estrumate injection

● Day 9-12: Perform FTAI 8 to 24 hours after the second Fertagyl 2 injection, or inseminate cows on detected estrous using standard herd practices.

Warnings: No meat withdrawal period and no milk withholding time are required when used according to the label. Keep out of reach of children.

Pharmacology and Toxicology: Endogenous gonadorelin is synthesized and released by the hypothalamus during various stages of the bovine estrus cycle following appropriate neurogenic stimuli. It passes, via the hypophyseal portal vessels, to the anterior pituitary to affect the release of gonadotropins (e.g., LH, FSH). Synthetic gonadorelin administered intramuscularly also causes the release of endogenous LH and FSH from the anterior pituitary.

Gonadorelin has been shown to have a low level of toxicity in animals. The LD50 for mice and rats is greater than 60 mg/kg, and for dogs, greater than 600 µg/kg. Untoward effects were not noted among rats or dogs administered 120 µg/kg/day or 72 µg/kg/day intravenously for 15 days.

It had no adverse effects on heart rate, blood pressure, or ECG to unanesthetized dogs at 60 µg/kg. In anesthetized dogs, it did not produce depression of myocardial or systemic hemodynamics or adversely affect coronary oxygen supply or myocardial oxygen requirements.

The intravenous administration of 60 µg/kg/day of gonadorelin to pregnant rats and rabbits during organogenesis did not cause embryotoxic or teratogenic effects.

The intramuscular administration of 1000 µg gonadorelin to normally cycling dairy cattle had no effect on hematology or blood chemistry.

Storage: Store at 2-8°C. The contents should be used within 28 days and stored below 25 °C after the first dose is removed.

Presentation: Fertagyl® 2 is supplied in multi-dose vials containing 20 mL or 100 mL of sterile solution.

Intervet Canada Corp., subsidiary of Merck & Co., Inc., 16750, route Transcanadienne, Kirkland, QC H9H 4M7

1 866-683-7838

Version date: July 7, 2015

® Registered trademark of Intervet International B.V. Used under license.

CPN: 1208211.5

Intervet Canada Corp.

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