What diagnostic tool is primarily used to evaluate tear production in dogs and cats?

The Schirmer tear test is the primary diagnostic tool used to evaluate tear production in dogs and cats. This test measures the quantity of tears produced by the lacrimal glands over a specified period, typically five minutes. During the test, a small strip of filter paper is placed under the lower eyelid, and the amount of moisture on the strip is measured in millimeters.

This evaluation is crucial in diagnosing conditions such as keratoconjunctivitis sicca (commonly known as dry eye), where tear production is notably reduced, leading to potential damage to the cornea and conjunctiva. By quantifying tear output, veterinarians can determine if the tear production is within normal limits or if there is a deficiency requiring further intervention or treatment.

Other options, such as fluorescein stain, are used for detecting corneal ulcers or assessing the integrity of the corneal surface; intraocular pressure measurement is primarily employed to diagnose glaucoma; and corneal palpation helps assess corneal sensitivity but does not provide information about tear production. Therefore, the Schirmer tear test is distinctly important for evaluating tear production and identifying related ocular conditions in veterinary patients.