Critter Culture
Why Are My Dog's Eyes Red?

Why Are My Dog's Eyes Red?

Critter Culture Staff



Dogs are man’s best friend and for good reason. They are loyal, enthusiastic, fun, and wonderful companions. When our best friends have a health condition that threatens that relationship, it is, of course, a cause for concern. Redness in a dog’s eye is not necessarily a serious condition. However, if you notice redness, it is a good sign that your dog needs to visit your local veterinarian for a thorough examination. There are a number of causes for red eye in dogs, many of which are also common to humans, and treating this phenomenon normally is somewhat routine and manageable.


Before Booking an Appointment

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The most common reason your dog is experiencing redness in his eye is due to inflammation. A veterinarian will need to be consulted, but you can make a rudimentary examination before booking an appointment. Check to see if there is discharge coming from the eye. Pus or mucus could be building up in the corners of the eye or covering the actual lens, in which case your dog will likely be letting you know it is bothering him. Try to remember if your dog has been in any unusual conditions, such as a new climate, a new home, or at a kennel for a stay. All of these will be important during the consultation.


Dry Eyes

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One of the most common causes of redness in dogs is dry eye. When this occurs, it is difficult for the dog’s eye to produce moisture to protect the eye and cornea. Look to see if your dog is having trouble blinking or seems to be bothered by the eye. Scraping, pawing, and rubbing its head on the surrounding area are good indicators. If your dog is experiencing dry eye, it is likely what is called immune-mediated adenitis. This is a condition wherein the tissue and valves that control the tear ducts become damaged or blocked. Your veterinarian will need to intervene to diagnose and treat this problem.


Pink Eye

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Conjunctivitis, or as it is more commonly known, pink eye, affects both humans and dogs. This is a condition caused by bacteria entering the tissue around the eye, leading to inflammation and redness. While common household and outside substances like pollen and dust can cause conjunctivitis, fecal matter getting into the eye can also be a cause. To prevent conjunctivitis, give your dog’s eyes a once over periodically, particularly after a long walk or hike. Wash your dog’s eyes regularly as well if you suspect he has been in contact with irritants. Your veterinarian can prescribe antibiotics to easily clear up conjunctivitis.


Cherry Eye

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Cherry eye is a rarer condition in dogs. Unlike humans, canines have a third eyelid that helps to further protect their corneas. If a dog is experiencing cherry eye, the ligaments, and muscles that control the function and retraction of this third eyelid weaken. This leads to the eyelid springing into the eye. When this occurs, it looks as though there is a cherry in the corner of the dog’s eye. Observe the working of the eyelids on your dog. If you suspect this is the cause of the redness, consult your veterinarian, who may be able to treat the condition.


Damaged Cornea

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Much like humans, dog eyes are delicate and vulnerable. Corneal damage is likely if your dog is quite active. Any outside substance can potentially damage his cornea. One of the most common ways this happens is in a forest or field where a dog can catch a cornea on a stray branch or tall bush. However, this can also happen at firework displays or if your dog gets into a fight with another neighboring animal. Consult your veterinarian for appropriate treatment. Mild conditions are usually treated by fitting your dog with an “Elizabethan” collar to prevent your dog from scratching the eye. More serious injuries require surgical intervention.


Types of Examinations

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Take your dog to the veterinarian even if you suspect the eye redness is mild or non-threatening. The vet will likely begin with a thorough physical examination in concert with a full medical history of the dog’s health. Depending on the severity of the redness in the eye, the vet might order further tests, such as a blood chemical profile, a urinalysis, and a blood count. In addition, to detect internal damage, your veterinarian may also order an X-ray or an ultrasound. These tests are conducted to rule out more serious problems like a cancerous growth.



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Check for signs of glaucoma in your dog’s eyes. This is a more serious health condition that requires medical treatment. When suffering from this condition, your dog will experience fluid build-up in their eyes, which, if left untreated, can lead to partial or complete blindness. It can also explain the redness in the eye if the glaucoma is in the early stages. However, if your dog is already presenting red eye symptoms, you will also likely be able to see swelling in the eyes as well. A dog experiencing glaucoma will present other symptoms as well. Observe and document if your dog is more sluggish than normal, is not eating properly, and has a loss of energy.


Monitoring Symptoms

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Observe the behavior of your dog and the condition of the eye once you have visited the veterinarian and received treatment. Take some common preventative measures as well. These include regularly cleaning the eye - especially if there is discharge or mucus build-up, cleaning the dog’s areas, and removing harmful irritants or dust build-up, and preventing your dog from abusive scratching and pawing at the eye. Look out for other warning signs in behavior as well, like change in eating patterns and energy levels. Make a note of any change in behavior or eye condition and report these to your veterinarian.



allergies, irritants, pollen, dust nimis69 / Getty Images

Bring your dog to the vet for regular check-ups, and ask for an allergy screening. Canines are just as susceptible to these seasonal irritants as humans, and preventative measures can help avoid future eye trouble. Common allergens include pollen, dust, fabric fibers, weeds, and pollutants in the air. Observe your dog’s eyes seasonally to determine whether there is a change in appearance or behavior in the transition between autumn, winter, spring, and summer. Veterinarians are reluctant to prescribe long-term allergy regimes for canines, but in serious cases where red eye is persistent, a treatment plan can be started.


Types of Treatment

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Ask your veterinarian about treatment options once she has diagnosed the cause of the red eye. For less severe cases, the wait-and-see method with an Elizabethan collar is often used. Common, too, are topical medications and ointments that you can administer at home with your dog. Provide your dog with oral medications, like antibiotics, if your dog is suffering from a bacterial infection like conjunctivitis. More serious cases, like cherry eye, will require surgical intervention. In the unfortunate case of cancer found through ultrasound, you may have various treatment options to battle the illness causing your dog’s red eye.


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