Red eyes in pets can be concerning. Like humans, pets can experience eye changes that range from mild irritations to serious emergency conditions. 

Here are five possible reasons why your pet’s eye is red, additional signs, and when to seek veterinary care at Caldwell Animal Hospital. 

1. Conjunctivitis in pets

Conjunctivitis, informally known as pink eye, is an inflammation of the conjunctiva, the tissue lining the eyelid and covering the sclera (i.e., the white part of the eye). Conjunctivitis can affect both cats and dogs in one or both eyes and can stem from a variety of causes, including bacterial, viral, or fungal infections, allergies, or smoke or dust exposure. If your pet’s eye is red because of conjunctivitis, you may see additional signs, such as:

  • Clear, yellow, or green eye discharge
  • Squinting or excessive blinking
  • Swollen eyelids
  • Rubbing or pawing at the eye

Conjunctivitis is not an emergency, but the condition is uncomfortable and potentially persistent. Medication may be necessary to relieve your pet’s discomfort or treat an underlying infection.

2. Allergies in pets

Similar to humans, pets can suffer from environmental allergies that cause eye inflammation and irritation. Your pet’s eye may be red because of exposure to pollen, dust, mold, or certain foods. Typically, allergic pets experience additional inflammation that varies depending on their allergy trigger, and signs may include:

  • Itchy skin or ears
  • Sneezing or coughing
  • Licking or chewing, especially on the paws
  • Scooting
  • Digestive upset

Allergies are uncomfortable and can lead to secondary issues, including skin infections and self-trauma. Contact our team if your pet’s eye is red and you see other allergy signs.

3. Uveitis in pets

Uveitis occurs when the uvea (i.e., the eye’s middle layer) becomes inflamed. Uveitis is a serious condition caused by infections, trauma, immune-mediated diseases, or cancer, and requires immediate veterinary care. Additional uveitis signs include:

  • Pain or sensitivity to light
  • Cloudy or bluish eye appearance
  • Decreased vision, or blindness
  • Excessive tearing or watery eyes

Delayed uveitis treatment can permanently impair vision, including secondary cataracts or glaucoma. Seek prompt veterinary care if your pet’s red eye is accompanied by sensitivity or behavior changes.

4. Glaucoma in pets

Glaucoma is an increase in intraocular pressure that can damage the optic nerve and lead to blindness if not treated promptly. Glaucoma can occur in one or both eyes and in any pet but is more common in certain breeds.

If your pet’s eye is red because of glaucoma, additional signs may include: 

  • Pain or discomfort (e.g., squinting, pawing at the eye)
  • Bulging or protruding eye
  • Dilated pupil
  • Vision loss

Glaucoma is extremely painful and should be treated as a veterinary emergency. In some cases, medication can control the condition, although blindness will eventually occur. Eye removal (i.e., enucleation) is recommended when other treatments fail. Seek immediate veterinary care if your pet’s eye is red, bulging, and painful. 

5. Corneal ulcers and injuries in pets

The cornea is the eye’s clear outer layer that can be irritated, red, or painful if injured.

Corneal ulcers and other injuries can occur from trauma (e.g., scratches), foreign objects in the eye (e.g., splinters or seeds), or infections. Ulcers may also occur secondary to certain health conditions or chronic dry eye. Discomfort is typically apparent and may include:

  • Squinting or holding the eye closed
  • Excessive tearing
  • Sensitivity to light
  • Eye discharge

Untreated corneal conditions can lead to increasing pain and may ultimately scar the corneal tissue, which may impair the pet’s vision. Deep or complicated ulcers may require surgical correction.

Why is my pet’s eye red? When to seek veterinary care

Ultimately, your pet will need a complete physical assessment and ocular examination to determine why their eye is red. If the redness persists for more than a day, or your pet is showing other pain or impairment signs, contact the certified Cat Friendly Caldwell Animal Hospital team to schedule an appointment. Our knowledgeable and caring team can advise you over the phone and help you determine whether your pet’s condition needs urgent attention or can wait for a scheduled visit.