Welcome to the all-new Vetlearn

  • Vetlearn is becoming part of NAVC VetFolio.
    Starting in January 2015, Compendium and
    Veterinary Technician articles will be available on
    NAVC VetFolio. VetFolio subscribers will have
    access to not only the journals, but also:
  • Over 500 hours of CE
  • Community forums to discuss tough cases
    and networking with your peers
  • Three years of select NAVC Conference
  • Free webinars for the entire healthcare team

To access Vetlearn, you must first sign in or register.


  Sign up now for:
Become a Member

Care Guide

About Care Guides[x] These care guides are written to help your clients understand common conditions, tests, and procedures, as well as to provide basic information about pet care. They are based on the most up-to-date, documented information, recommendations, and guidelines available in the United States at the time of writing. Pharmaceutical product licensing, availability, and usage recommendations are based on US product information. Use the Download Handout button to generate a PDF for printing or e-mailing to your clients.

Fluorescein Stain

    • Fluorescein stain can be applied to the eye to detect injuries involving the cornea.
    • Corneal scratches, ulcers, or other defects can be diagnosed using fluorescein staining.
    • Performing a fluorescein stain takes only a few minutes and is not painful for your pet.

    What Is a Fluorescein Stain?

    A fluorescein test is a test that can help detect injuries to the cornea, which is the clear, thin layer of tissue that covers the front of the eye. The cornea must remain transparent to support vision, but this transparency makes detecting scratches or other injuries on the cornea very difficult because they are invisible.

    Fluorescein is a green-tinted dye that fluoresces (glows) under blue light. A small amount of this dye applied to the surface of the eye (on top of the cornea) can be used to detect corneal injuries.

    How Is a Fluorescein Stain Performed?

    Fluorescein dye is available in several formulations, including a small paper strip that can be placed directly onto the eye and a liquid solution that can be applied into the eye.

    Corneal injuries may be invisible, but they tend to be very painful. Animals with these injuries may have red, swollen, watery eyes, or may squint or rub their eyes. If your veterinarian suspects your pet may have an injury on the cornea, a small amount of fluorescein dye is applied to the surface of the cornea. If the corneal surface is intact, the fluorescein dye will not stick to the eye. However, if there is a scratch, ulcer, or defect on the cornea, the dye sticks to the injured area and can show your veterinarian where and how serious the injury is.

    Performing a fluorescein stain takes only a few minutes and is not painful for your pet.

    What Does a Fluorescein Stain Tell Your Veterinarian?

    Fluorescein staining can tell your veterinarian if your pet has a scratch, ulcer, or other defect on the surface of the cornea. If there is an injury, the results of this test can show your veterinarian where and how serious the injury is.

    Because the tear ducts in the eye normally drain through the nostrils, the fluorescein stain test can also help determine if your pet’s tear ducts are clogged. If the tear duct system is functioning normally, the green-colored dye is visible at the nostrils within a few minutes after being applied to the eye. If the dye is not visible at one or both nostrils, this could indicate clogging or other problems with the tear ducts.

    Fluorescein staining is not painful and can provide valuable information about the condition of your pet’s eye and tear duct system.