If your dog or cat is exhibiting signs of an eye problem, your veterinarian will perform a complete physical examination, followed by three basic eye health tests. The three tests together take only minutes, they are performed in the examination room, and they are well tolerated by pets.
Look Into Their Eyes
Your pets can experience a number of eye problems, from dry eye to high ocular pressure to corneal scratches. Eye diseases in dogs and eye diseases in cats present with similar signs and symptoms. Some signs that your pet needs to be evaluated by your veterinarian include:
- Squinting or blinking
- Redness or cloudiness of the eyes
- Swelling around the eyes
- Excessive tearing or tear staining on the face
- Pawing at the eyes or rubbing them on a surface
- Discharge from the eyes
- Visible or bulging third eyelid
These signs may be unilateral, meaning visible in one eye, or bilateral, which means occurring in both eyes.
The Schirmer Tear Test
This is the gold standard for diagnosing dry eye. To perform this test, the end of a paper strip is inserted into your pet’s lower eyelid. This paper strip is marked with ascending numbers. As the paper takes up tears, it turns from white to blue in color. The strip is left in place for one minute before the veterinarian removes the strip and notes the highest number at which the paper’s color change ceased. The number indicates your pet’s tear production. If the number is too low, then your pet may be treated for dry eye. If the number is too high, then your veterinarian will need to determine what is irritating your pet’s eye to prompt an accelerated tear production. Foreign particles and ingrown eyelashes are two of the more common culprits. Both of your pet’s eyes will undergo this test.
The Tonometry Test
To perform a tonometry test, a handheld device is used. Your veterinarian makes direct contact between the tip of the device and the cornea of your pet’s eye. Once the gentle pressure registers a number on the device, contact is repeated three times. The average of these resulting numbers indicates your pet’s intraocular pressure. This test must be performed on both of your pet’s eyes. High intraocular pressure indicates glaucoma, a serious eye condition that is painful and results in blindness.
The Fluorescein Stain Test
This test is performed last because the eyes must be stained with a fluorescing dye. The purpose of the stain is to reveal any corneal scratches or ulcerations. The most common causes of such trauma are tree branches, brush and torn or bent fencing which can scratch or poke eyes when an inquisitive pet is exploring. A paper strip that contains the dye is quickly touched to each of your pet’s eyes. As your pet blinks, the fluorescent green dye is spread across the corneal surfaces of the eyes. The room is then darkened, and the veterinarian peers into each eye through an ophthalmoscope. The stain outlines any abnormal surfaces on the cornea. Once your veterinarian has completed his or her examination, the excess stain is rinsed away from your pet’s eyes with an eyewash solution.
The Treatment Plan
Your veterinarian can treat many of the common eye conditions and superficial corneal injuries. A treatment plan will likely include prescription drops or ointments that you will need to apply at home. If your pet is persistent about scratching or rubbing at its affected eye, an Elizabethan collar may be necessary to prevent further irritation and to allow the eye to heal. Your veterinarian will need to recheck the eye to determine that the condition is healing properly. Some of the more serious eye diseases in dogs and eye diseases in cats require surgical treatment.
If your veterinarian cannot make a diagnosis from the aforementioned eye health tests, or if he or she diagnoses a serious problem that requires specialized testing and treatment, you may be referred to a board-certified veterinary ophthalmologist to ensure the best chance at preserving your furry friend’s sight.