Why Are My Dog’s Eyes Red?

Why Are My Dog's Eyes Red?

Recently, I was bothered by my dog’s eyes that appeared to be red. I eventually checked on them and have seen nothing. The next day, they are still red, and I realized it was because of his long hair getting into his eyes. It seemed irritated, so I brought him to the vet and had him treated. My dog then had a haircut to avoid it from happening again. I know many dogs have experienced the same thing. It can be easily noticed since it is usually visible.

Like humans, dog’s eyes are also sensitive. They become red due to a variety of reasons, and it needs to be treated immediately, since it may cause them discomfort, or worst, can lead to complications. Now, let’s answer the question “Why are my dog eyes red?” and talk about the common reasons for the redness of our dogs’ eyes.

Why Are My Dog’s Eyes Red?

1) Irritation

Irritation in the eyes would cause redness. It is due to allergens or foreign objects that get into our dog’s eyes, such as dust, hair, dirt, and many more. As I mentioned previously, it happened to my dog because of its hair getting into its eyes. Sometimes, we don’t realize that their eyes are irritated until it becomes red.

Signs of Irritation:

  • redness
  • swelling
  • rubbing his eyes
  • blinking
  • irregular pupils
  • pus discharge
  • Teary eyes


Allergies do not only occur in humans but also in dogs. A study says that humans and dogs share many of the same allergy symptoms, particularly food-related allergies. Allergies in dogs can be food or environmental. Also, our dogs might be exposed to environmental agents such as dust, pollens, molds, etc, or they can be allergic to specific foods that cause them to have allergies. These allergies would cause their eyes to be red.

Signs of Allergies:

  • Redness
  • Itchiness
  • hair loss
  • Swelling
  • Inflamed skin
  • Sneezing
  • Licking or scratching

3) Trauma

A dog’s red eye can also be caused by trauma and injury from an accident or impact on its eye surface. It can happen when our dog accidentally crashed or bangs his eye while playing. Or there could be solid objects that have lodged into his eyes. It usually affects only one eye. If the impact isn’t too bad, it will more likely recover quicker. Yet, if it’s severe and may have hit his cornea, he should be immediately treated as it can lead to blindness.

Signs of Trauma in the eyes:

  • Redness
  • Swelling (if the impact was strong)
  • Reddening of the tissues around the eye/s
  • Rubbing his eyes (can be because of pain or itchiness)

4) Dry Eyes

Dry eyes in dogs, also known as Keratoconjunctivitis sicca, occur when the tear glands don’t produce enough moisture or tears. It can cause inflammation of the cornea and the surrounding tissues. It can be painful for dogs, and it gets worse over time if left untreated.

Signs of dry eyes:

  • redness
  • blinking
  • loss of vision
  • rubbing at the eyes
  • watery discharge
  • mucous production

5) Conjunctivitis

It is also known as “pink eye”- both common in dogs and humans. It is the inflammation of the conjunctiva, a membrane that coats the eye and the lining of the eyelids.

Signs of conjunctivitis:

  • redness
  • watery discharge
  • squinting
  • swelling of the eyelid lining

6) Glaucoma

Like, humans, dogs can also develop Glaucoma. Glaucoma is a liquid build-up due to an imbalance in the fluid production in the eye that increases eye pressure. This high pressure would cause damage to the retina and optic nerve.  It’s a condition that needs immediate medical attention to avoid the total blindness of our dogs.

Signs of Glaucoma

  • Teary eyes/watery discharge
  • Redness
  • Eye pain
  • Lethargy
  • Blindness (if not treated)

7) Uveitis

Intense reddening of the eye with severe pain is one of the symptoms our dogs experience when they have Uveitis. They tend to avoid bright lights and keep their eyes close often. Uveitis occurs when the uveal tract is inflamed. Common causes are infections (bacterial, fungal, viral, parasitic), and other diseases such as hypertensionulcerative keratitis, diabetes mellitus, trauma, and many more. Non-treatment of uveitis can lead to glaucoma, scarring of the uveal structures, and worse is blindness.

Signs of Uveitis

  • Redness
  • Swelling of the eye area or the eyeball
  • teary eyes/water discharge
  • sensitivity to lights
  • squinting
  • excessive blinking
  • bleeding
  • severe pain
  • cloudiness
  • possible rubbing or pawing at the eye

8) Tumor

It is a growth of a mass behind or within the eye. There are no direct reasons why dogs may develop this, but it can be caused by environmental risk factors or genetics. There are several types of eye tumors: eyelid tumors, orbital tumors, tumors of the cornea, uveal melanoma, and limbal melanoma. Eyelid tumors are the most common eye tumors in dogs, and they can be removed through surgery.

Signs of Tumor:

  • redness
  • inflammation of the eye (the uvea)
  • Glaucoma
  • Hyphema
  • Mass growth behind or around the eyes

Treatment for Red Eyes in Dogs

The treatment for the redness in dogs’ eyes varies in the severity of the condition. Each cause has its diagnosis and treatment. The moment that we see the signs above associated with the redness of our dog’s eye, we should immediately call the vet or take our dog to the nearest vet for proper medications and treatment. Usually, to alleviate the pain they feel, it’s recommended to do a hot/cold compress. There are also special eye drops and antihistamines for redness caused by an allergy. If it is a severe condition, the vet will let us know the next necessary steps. Again, we shouldn’t self-diagnose our dogs if we don’t have enough knowledge.