Several toxic substances can cause eye irritation, ulcerations, dry eye, and blindness, if your pet is exposed. Our team at Veterinary Vision Center wants to provide information on the toxins that can damage your pet’s eyes, and what you should do should your pet be affected.

Toxins can cause eye irritation in pets

Soaps and shampoos that get in your pet’s eyes will cause irritation. If this occurs, flush your pet’s eye for 20 to 30 minutes using sterile saline or tepid water. 

  • Technique — Fill a sterile saline bottle, a clean syringe without the needle, or an eye dropper with the flushing solution. Use a cotton ball or clean washcloth to soak up the toxic fluid, and then squeeze the solution in your pet’s eye. Hold the flushing tool as close to the eye as possible, without touching the eye surface, and allow the fluid to flow across the eye in a slow, steady stream. 
  • Contraindications — Do not flush your pet’s eye with high-pressure spray devices, since this could damage their cornea. Also, do not use neutralizing agents, allergy eye drops, and redness relief eye drops, which are not appropriate for pets. To prevent further irritation, do not allow your pet to rub or scratch their eye.
  • Follow up — After flushing your pet’s eye, a veterinary professional should check to ensure the cornea has not been ulcerated.

Toxins can cause eye ulcerations in pets

Toxins such as chemical substances and dry wall dust can cause corneal ulcerations in pets, and can cause significant problems for your pet if not treated properly.

  • Signs  — Corneal ulcerations caused by toxins are typically extremely uncomfortable. Signs include tearing, surrounding redness, and an inability to open the eye.
  • Diagnosis — A veterinary professional will use a fluorescent stain strip to diagnose a corneal ulceration. The stain adheres to the damaged tissue, but does not stick to healthy corneal tissue, making the ulcerated area appear bright green.
  • Treatment — Topical antibiotics help prevent secondary bacterial infection in corneal ulcerations, and medication to dilate the pupil is also typically used for pain relief. Elizabethan collars are commonly recommended to prevent the pet from self-trauma from rubbing or scratching the eye.

Toxins can cause dry eye in pets

Drug toxicity, such as sulfa-containing antibiotics, has been linked to keratoconjunctivitis sicca (i.e., dry eye) in pets. Appropriate tear production is necessary to lubricate the cornea, flush away irritants and infectious agents, supply nutrients to the cornea, and remove metabolic wastes. Dry eye can be extremely uncomfortable, and can cause corneal ulcerations, if not treated properly.

  • Signs — When tears are deficient, the eyes become irritated, the conjunctival tissues surrounding the eyes turn red, and a thick, yellow ocular discharge is created.
  • Diagnosis — A Schirmer tear test is used to diagnose dry eye. A sterile paper strip is placed inside the lower eyelid for 60 seconds, tears moisten the paper, and  the moistened area is then measured. Fifteen millimeters or more is normal, 11 to 14 is borderline, 10 or less is dry, and 5 millimeters or less is severely dry.
  • Medical treatment — Treatment is aimed at improving the pet’s quality of life and preventing complications, such as corneal ulceration. Medications include immunomodulating drugs, artificial tears, topical antibiotics, and topical steroids.
  • Surgical treatment — If dry eye is severe and unresponsive to treatment, a parotid duct transposition can be performed, redirecting the duct, which provides the mouth with saliva, to the inside of the lower eyelid, to deliver saliva to lubricate the eye.

Toxins can cause blindness in pets

Several toxins can cause blindness in pets when ingested or absorbed through the skin.

  • Ivermectin — This medication is used in many heartworm preventives, and to treat other parasites, such as ear mites and intestinal worms. However, if too much drug is administered, or the dog has a genetic sensitivity, ivermectin can cause retinal edema and separation, leading to blindness. Signs will include pupil dilation, lethargy, disorientation, and vomiting. Breeds who have a genetic predisposition include collies, Australian shepherds, German shepherds, and border collies. A pet who loses their vision from an ivermectin toxicity typically does not regain their sight.
  • Organophosphates — These insecticides are used in many lawn and garden products and pet flea and tick treatments. A pet is overexposed to organophosphates when a product is misused, or multiple insecticides are used at once, and absorbed through the lungs, skin, or gastrointestinal tract. An organophosphate toxicity also can damage your pet’s retina, optic nerve, and extraocular muscles. In addition to blindness, signs include constricted pupils, muscle weakness, drooling, and vomiting. Prognosis for vision return is poor.

Toxins can pose a significant hazard to your pet’s eyes, but you can help prevent ocular tissue damage by carefully reading product labels, and knowing how to correctly flush a toxin from your pet’s eye. If your pet’s eye has been affected by a toxin, contact our Veterinary Vision Center team, so we can help salvage their sight.