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CIDR 330 (Canada)

This page contains information on CIDR 330 for veterinary use.
The information provided typically includes the following:
  • CIDR 330 Indications
  • Warnings and cautions for CIDR 330
  • Direction and dosage information for CIDR 330

CIDR 330

This treatment applies to the following species:
Company: Zoetis

progesterone releasing intravaginal insert

Veterinary Use Only

for sheep

DIN 02353881


CIDR® 330 is an intravaginal progesterone release insert containing the naturally occurring hormone progesterone. Attached to each CIDR 330 intravaginal insert is a nylon tail. Each CIDR 330 intravaginal insert contains 0.35 grams progesterone USP, in molded silicone over a flexible nylon spine. The empirical formula for progesterone is C21H30O2.

The CIDR 330 intravaginal insert provides an exogenous source of the hormone progesterone during the administration period. Removal of the CIDR 330 intravaginal insert results in a rapid fall of plasma progesterone levels, which results in synchronization of estrus in those animals responding to treatment.

Active Ingredient

Progesterone USP, 0.35 grams per CIDR 330 intravaginal insert.

CIDR 330 Indications

CIDR 330 intravaginal insert is indicated for the induction of estrus in ewes (sheep) during seasonal anestrus*.

*Note: Seasonal anestrus is when ewes do not have regular estrous cycles outside the natural breeding season.

Dosage and Administration

For use with the CIDR 330 applicator.

Administer one CIDR 330 intravaginal insert into the vagina of each ewe to be treated for 5 days. After insert removal, use standard flock breeding procedures to breed ewes at induced estrus. In ewes responding to treatment, the onset of estrus generally occurs within 1 to 3 days after removal of the CIDR 330 intravaginal insert.

Make sure to have sufficient number of rams to adequately breed all ewes with an induced estrus. Breeds of rams may vary in libido in the non-breeding season. Therefore, a ewe to ram ratio up to 18:1 is recommended for multi-sire situations. For single sire situations, 12:1 for ram lambs and up to 18:1 for yearling rams are recommended.


1. Avoid contact with skin by wearing latex gloves when handling CIDR 330 intravaginal insert.

2. Only use the specially designed CIDR 330 applicator for administration.

3. Restrain ewes appropriately prior to administration.

4. Wash the CIDR 330 applicator in a non-irritating antiseptic solution, and then apply a veterinary obstetrical lubricant to the end of the CIDR 330 applicator. The CIDR 330 applicator should be washed and/or disinfected between animals.

5. Push the flexible tail of the CIDR 330 intravaginal insert into the CIDR 330 applicator taking care to assure the tail is extending upward through the slot of the CIDR 330 applicator and is pointed toward the handle.

6. Fold the wings of the CIDR 330 intravaginal insert to make it longer and continue to advance the insert into the CIDR 330 applicator until it is fully seated with only the tips of the wings protruding from the end of the CIDR 330 applicator (see Figure 1).

7. Lubricate the protruding tips of the wings of the CIDR 330 intravaginal insert with veterinary obstetrical lubricant.

8. Clean the exterior of the vulva with disposable tissue.

9. Open the lips of the vulva and gently place the loaded CIDR 330 applicator through the vulva. The slot in the CIDR 330 applicator should face downwards (see Figure 2).

10. Once the loaded CIDR 330 applicator is past the vulva, slope the CIDR 330 applicator slightly upwards (35 - 45° angle) by lowering the handle, and then forward, without forcing, until the CIDR 330 applicator is fully inserted or resistance is felt (see Figure 3).

11. Squeeze the finger grips within the handle of the CIDR 330 applicator to deposit the CIDR 330 intravaginal insert in the anterior vagina (see Figure 4) and then pull the CIDR 330 applicator backwards to remove it from the vagina.

12. With the CIDR 330 intravaginal insert correctly placed, with the wings open in the anterior portion of the vagina, the tail of the CIDR 330 intravaginal insert should be visible, pointing downward from the vulva of the ewe.


1. Remove CIDR 330 intravaginal inserts by pulling, gently but firmly, on the protruding nylon tail.

2. CIDR 330 intravaginal inserts may reverse direction within the vagina; therefore, if the nylon tail of the insert is not visible on the day of removal, check the vagina to determine if an insert is present.

3. Used (removed) CIDR 330 intravaginal inserts should be stored in a sealable container until disposed. Sealed bag/container with used CIDR 330 intravaginal insert should be properly disposed in accordance with any applicable local or provincial regulations.

Note: In a multilocation study conducted in the U.S., retention rates from 90 to 100% were observed in ewes, with an average of 97.3%.


Treated animals must not be slaughtered for use as food at least 1 day after removal of the CIDR 330 intravaginal insert.

Wear latex gloves when handling CIDR 330 intravaginal inserts.

Keep out of reach of children.


Do not use in ewes with abnormal, immature or infected genital tracts.

Do not use in ewes that have never lambed.


CIDR 330 intravaginal inserts have not been tested in estrous cycling ewes.

Do not use an insert more than once. To prevent the potential transmission of venereal and blood borne diseases, the CIDR 330 intravaginal insert should be disposed of after a single use. If loss rates are high, re-evaluate insertion technique. Contact a veterinarian if abnormal bloody discharge is observed during treatment. Care must be taken when using the CIDR 330 applicator so as not to damage the vagina. Animals in poor condition resulting from illness or nutritional stress may not respond to this drug.

Adverse Reactions

The following may be noticed:

Clear, cloudy, yellow or bloody mucus on the outside of CIDR 330 intravaginal insert when removed from ewes. The mucus may have an offensive odor. This is a result of mild irritation to the vaginal lining by the presence of the CIDR 330 intravaginal insert, and generally clears between the time of removal and breeding. Such irritation does not affect fertility.


Store between 15 and 30°C.

PRESENTATION: CIDR 330 intravaginal insert is available in bags of 20 inserts.

Zoetis is a trademark and CIDR is a registered trademark of Zoetis or its licensors, used under license by Zoetis Canada Inc.

Zoetis Canada Inc., Kirkland QC H9H 4M7



CPN: 1198441.2

Order Desk:   800-663-8888
Technical Services Canada:   800-461-0917
Technical Services USA:   800-366-5288
Every effort has been made to ensure the accuracy of the CIDR 330 information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the Canadian product label or package insert.

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