Numerous issues, from a minor irritation to a serious health condition, can cause eye redness in pets, potentially endangering their vision. Our Animal Care & Emergency Services team knows the importance of your pet’s eyesight, and we explain how you can help ensure your furry pal’s vision remains good. Learn about eye redness causes in pets so you know when to seek immediate veterinary care.

Conjunctivitis can cause eye redness in pets

Conjunctivitis is inflammation of the tissue that covers the white part of the eyeball and lines the eyelids. The condition can be caused by issues such as bacterial or viral infection, trauma, environmental irritants, tear film deficiency, and eyelid abnormalities. Signs include eye redness, excessive tearing, and rubbing at the eye. 

Our team determines the underlying cause of your pet’s eye redness by thoroughly examining their eyes and overall health. Treatment depends on the underlying cause but may include topical eye ointments or drops as well as oral medications. 

Corneal ulcers can cause eye redness in pets

A corneal ulcer is a defect in the clear structure that covers the front of the eye. The most common cause is trauma, but an eye infection can also lead to a corneal ulcer. Corneal ulcers are typically extremely painful, and signs include holding the eye closed, eye swelling, eye redness, clear or mucoid ocular discharge, and rubbing at the affected eye.

Veterinarians use fluorescein, a special stain, to detect corneal ulcers. The stain adheres to only the damaged tissue, highlighting the affected area. Prompt treatment is necessary to help prevent infection. Affected pets typically need eye medications every four to six hours, and usually systemic pain medications as well. In severe cases, surgery is necessary to remove dead corneal tissue or to perform a corneal graft. 

Keratoconjunctivitis sicca can cause eye redness in pets

Keratoconjunctivitis sicca (i.e., [KCS] or dry eye) occurs when the pet has an inadequate tear supply. The most common cause is an immune-mediated disorder that attacks the pet’s tear-producing glands. Other causes include infection, certain medications, hypothyroidism, and damage to the nerves that innervate the tear glands. An affected pet’s eyes are painful, red, and irritated, and your furry pal may hold their eyes shut or blink excessively. In addition, a thick, yellowish, mucoid discharge is often present. Secondary corneal ulcers are common.

Veterinarians diagnose KCS using the Schirmer tear test, which involves inserting a special wicking strip into the pet’s lower eyelid to measure their tear production in one minute. Treatment objectives are to stimulate tear production and protect the cornea. 

Entropion can cause eye redness in pets

Entropion is an anatomical abnormality that causes the eyelids to roll inward, allowing the hair on the eyelid surface to rub the cornea. The chronic irritation can lead to corneal ulcers and scarring that can inhibit vision. Certain breeds, such as blood hounds, bull mastiffs, shar peis, English bulldogs, Labrador retrievers, and Persian cats, are at an increased risk. Signs include excessive tearing, eye redness, holding the eye closed, and a mucoid ocular discharge.

Entropion is typically evident on an ophthalmic examination, but other tests may be necessary to check for corneal ulcers or decreased tear production. Treatment typically involves surgery to correct the abnormal eyelid. 

Uveitis can cause eye redness in pets

Uveitis is inflammation of important internal eye structures and is caused by issues such as infection, metabolic disease, high blood pressure, trauma, autoimmune disease, and eye tumors. Signs include eye redness, holding the eye completely or partially closed, excessive tearing, and in some cases, corneal cloudiness. 

Uveitis can typically be diagnosed during an ophthalmic examination, but other diagnostics may be necessary to determine the underlying cause. Treatment aims to reduce inflammation, relieve pain and discomfort, and prevent secondary complications such as glaucoma, lens luxation, and retinal detachment. 

Glaucoma can cause eye redness in pets

Glaucoma occurs when the eye pressure is elevated and can be caused by an inherited drainage angle abnormality or develop secondary to conditions such as uveitis, tumors, lens luxation, and intraocular bleeding. Signs may include eye redness, rubbing at the eye, eye bulging, and watery eye discharge. If not treated, glaucoma can damage the optic nerve, causing blindness.

Veterinarians diagnose glaucoma by using a tonometer to measure the eye’s pressure. Treatment involves topical eye medications to decrease intraocular fluid production and promote drainage as well as systemic medications to alleviate pain. In severe cases, surgery is necessary to reduce the intraocular pressure. If the pet’s intraocular pressure can’t be controlled, the eye should be removed to prevent chronic pain. 

Eye issues can quickly escalate and threaten your pet’s vision. If your pet has a red, squinty eye, contact our Animal Care & Emergency Services team so we can assess the problem and devise an appropriate treatment plan.