metadata toggle
Clinical particulars
Target species
Cattle, horses and dogs
Indications for use
Chorulon can be used in the following fertility problems in domestic animals:
- cases of repeated failure of conception in cows and heifers
- induction of ovulation in mares and bitches
- cases of cystic ovaries in cows and heifers
- anoestrus in mares and bitches
- delayed ovulation, prolonged pro-oestrus in bitches
- deficiency in libido in male dogs
Special warning for each target species
Special precautions for use
Operator warnings
Care should be taken to avoid accidental self-injection; if accidental self-injection occurs, seek medical advice immediately and show the doctor this label.
Wash hands after use.
Adverse reactions
In rare cases, as with all protein preparations, anaphylactoid incidents may occur shortly after injection. Adrenalin injection (1:1,000) given intravenously or intramuscularly when symptoms appear is the standard treatment. The administration of corticosteroids may also be indicated.
Use during pregnancy or lactation
Not applicable.
Amounts to be administered and administration route
Reconstitute with the solvent provided, ensuring the freeze-dried plug is fully dissolved. Administer by intramuscular or intravenous injection, observing the usual aseptic precautions.
Cow and heifer:
Repeated failure of conception: 1500 IU - i.m. or i.v. at AI or mating.
Cystic ovarian disease (anoestrus, prolonged oestrus, nymphomania): 3000 IU - i.v.
Enhancement of luteal function: 1500 IU i.m. 12 days after insemination or mating.
Suboestrus (follicles > 2 cm in diameter): 1500 – 3000 IU - i.m. or i.v., repeat after 2 days if necessary.
Induction of ovulation: 1500 – 3000 IU - i.m. or i.v 24 hours before AI or mating.
Anoestrus: 500 IU - i.m. or i.v. at first day of oestrus after pre-treatment with PMSG 20 IU/kg s.c. daily for 10 days.
Delayed ovulation, prolonged pro-oestrus: 100 - 800 IU/day - i.m, repeating treatment until vaginal bleeding disappears. Mate on behavioural oestrus.
Male dog:
Deficiency in libido: 100 -500 IU - i.m. twice weekly for up to 6 weeks, but if this is not possible then 100 – 500 IU i.m. 6-12 hours before mating may give a temporary effect.
Further information
The product has been used in cases of cryptorchidism in the dog prior to castration (100-500 IU i.m. twice weekly for up to 6 weeks). Treatment may be effective in some cases provided that the inguinal canal is patent, and that therapy commences early.
The product has intrinsic LH-like activity. Injection of 1500 IU 12 days after heat in cattle enhances the active life of the corpus luteum by 2 to 3 days, resulting in increased progesterone and suppression of oestradiol production. These changes are consistent with those observed after GnRH use at day 11-13 of the cycle which are believed to be responsible for the increased pregnancy rates seen after such use. The mode of action is however different, since the product does not rely on first stimulating an endogenous LH peak. This use of the product has not been investigated in the field.
No specific treatment or antidote recommended.
Withdrawal periods
Cattle: Meat – Zero days.
Milk – Zero hours.
Horses: Meat – Zero days.