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Witness LH (Canada)

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

Witness LH

This treatment applies to the following species:
Company: Zoetis


I. General Information

WITNESS® LH test provides an accurate, semiquantitative measurement of canine and feline luteinizing hormone (LH) in serum samples. This assay, when used in conjunction with progesterone testing, identifies the pre-ovulatory LH surge, and thus, the time of ovulation. It may also be used to distinguish ovariectomized from sexually intact bitches or queens.

Ii. Test Principles

WITNESS® LH is an immunochromatographic assay that uses gold-conjugated antibodies to give a visual line in the presence of luteinizing hormone in dog or cat serum.

Sensitized particles bound to the luteinizing hormone present in the serum sample migrate along a membrane.

The complex is then captured on a sensitized reaction zone where its accumulation causes the

formation of a clearly visible pink/red band.

A control band located at the end of the reading window (3) ensures that the test was performed correctly.

A positive result occurs when a line appears in the test area which is of similar or greater intensity than the control line. When this occurs, the LH level in the serum sample is greater than 1 nanogram per milliliter.


● The test can be performed on canine or feline serum. WITNESS® LH requires only four drops of serum to run each test.

● Always collect samples with a sterile needle and syringe.

● The sample should not be haemolysed or lipemic.

Iv. Sample Storage

Serum samples should preferably be tested on the same day as sample collection.

If testing is further delayed, samples should be kept refrigerated (up to 24 hours at 2°C to 8°C).

For long term storage, serum samples should be kept frozen (-20°C; or colder). Do not thaw and refreeze.


● 6 pouches, each containing a test device

● 6 pipettes

● Instructions for use


● Do not use this kit or any of its components after the expiration date.

● Kit should be stored at +2 °C - 25 °C. Kit should not be frozen.

● Use the test immediately after the pouch is first opened (within 10 minutes).

● Avoid touching or damaging the membrane in the sample well or the results window.

● The WITNESS® device should be placed on a flat, horizontal surface while performing the test.

● Use a separate pipette for each sample.

● Hold pipette vertically when dispensing sample.

● Handle all samples as biohazardous material.

● For veterinary use only.

Vii. Test Procedure

Prior to use, allow SAMPLE to come to room temperature (20° to 25°C).


● Tear open a pouch provided and place the test device on a flat horizontal surface.

● Holding the provided pipette vertically, add four drops of sample to the test well (1).

● Leave the test device flat during migration of sample/reagent complex through the reading windows.


● After 20 minutes, observe the presence or absence of pink/red bands in the reading windows (2) and (3).


Valid Results

● Test is VALID if a pink/red band is present in reading window (3).

Interpretation of Results

NEGATIVE. If no line appears in reading window (2), the LH value is less than 1 nanogram per milliliter. Continue LH testing on a daily basis to determine the optimal time to breed.

POSITIVE. Field observations have shown if a line appears in reading window (2) which is of similar or greater intensity than the control window (3), the LH value is greater than 1 nanogram per milliliter. Field observations have shown if a distinct line appears in reading window (2) of less intensity than control window (3), the sample is likely to contain slightly less than 1 nanogram per milliliter and have been drawn before or after the LH surge (the shoulders of the LH peak). If the daily tests for the LH surge do not reveal a stronger test line, field observations have shown the weaker intensity line should be considered as indicative of the LH surge. Progesterone values may help confirm.


The test is complete and may be read before 20 minutes if both control and test pink/red bands are visible. The presence of only the control band on the strip before 20 minutes does not mean that the test is complete, as a test band may appear more slowly than the control band.


Zoetis Inc., Kalamazoo, MI 49007, USA


Zoetis Belgium SA, Rue Laid Burniat 1, 1348 Louvain-la-Neuve, BELGIUM

For product information call:

US VMIPS 1-888-963-8471

Canada 1-800-461-0917


CPN: 1198512.3

Order Desk:   800-663-8888
Technical Services Canada:   800-461-0917
Technical Services USA:   800-366-5288
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Copyright © 2023 Animalytix LLC. Updated: 2023-05-30