Why are my dog’s eyes red?

There are many ways dogs' eyes signal their overall well-being. When looking into those sweet puppy eyes and noticing redness or unusual discharge, it's time for a checkup. 

Here are some reasons why your dog's eyes are red and what you can do at home to care for them. Plus, when to seek help from a vet.

Common dog eye infections 

Healthy dog eyes should be clear and bright. They shouldn't be sensitive to light, and there shouldn't be discharge or crusting around the eyes.

"Any time a dog's eyes are red, especially if it's not improving over 24 hours, your dog should have an exam," Dr. Sarah McCormack, DVM, a veterinarian at Northwest Neighborhood Veterinary Hospital, says. "Eye conditions can rapidly get worse and even lead to loss of vision."

Here's how to spot some of the most common reasons for dogs' red, irritated or swollen eyes. 

• Eye infection: The symptoms of a dog eye infection can look like a human eye infection: redness in the whites of the eyes, clear, yellow or green discharge, and excessive blinking or squinting. Eye infections can be bacterial or viral, and if the infection is related to an upper respiratory infection, your dog might be coughing and sneezing, too.
• Conjunctivitis: Also called pink eye, conjunctivitis in dogs can be spotted by the inflammation of the tissue surrounding the eye and redness of the whites of the dog's eye.
• Dry eye: When dogs don't produce enough tears, they can develop dry eyes. In addition to red, irritated eyes, your pup might blink or squint more frequently.
• A scratch or injury: If your dog injured their eye, it could look red and have a watery discharge. They might also blink excessively or paw at the hurt eye.
• Allergies: Seasonal dog allergies and other inhalant allergies can cause upper respiratory irritation like coughing, sneezing, wheezing and nasal discharge. Dogs' allergies can look and feel a lot like human allergies and can cause your dog's eyes to be red and swollen.
• Glaucoma: This condition is common in dogs and is caused by increased eye pressure. When the production and draining of fluid are out of the norm, it can cause the pressure to increase. Signs of glaucoma in dogs include red eyes, swelling of the eyeball and even a loss of vision.

RELATED: Cataracts in dogs

Are dog eye boogers normal?

What we call eye boogers are totally normal for dogs to get. You can tell those common, crusty eye boogers apart from other abnormal eye discharge by color and consistency — eye boogers can be pale, clear or black mucus. 

"Anything yellow-green, crusting around the eye or bothering the dog is not normal," Dr. McCormack adds.

Treatments for red eyes in dogs

Brachycephalic dogs (aka pups with short skulls) and small breeds like Boxers, French Bulldogs, Boston Terriers, pugs and Chihuahuas are prone to eye infections and irritation, Dr. McCormack says. They have more shallow eye sockets than other pups, so keeping their hair neatly trimmed around the eyes will help prevent irritation from stray hairs. 

Excessive eye boogers, dirt or goo, can cause redness or irritation of the eye in any breed. Use a soft cloth or towel dampened with warm water to clean your dog's eyes. Gently wipe from the inside of the eye outward.

If the redness, irritation or abnormal discharge persists, schedule an appointment with your vet. They may recommend an over-the-counter allergy medication or prescribe an ointment or even dog eye drops. Before giving any medications at home, be sure to talk with your vet.

We recommend enrolling in dog insurance so that if you do need to take your pup to the vet for red eyes (or another unexpected illness or injury), Fetch can help reimburse you for treatment.