Why are my dogs eyes brown? Essential Tips

Causes of Pigmentary Keratitis in Dogs

Pigmentary keratitis is the direct result of repeated irritation and inflammation from structural, environmental, or infectious conditions. The pigmentation is formed when chronic inflammation prompts the collection of melanin granules that embed and darken the innermost layer of the cornea. Most commonly, this condition is seen in brachycephalic breeds including Pugs, Boxers, Bulldogs, and French Bulldogs.

There are several possible causes of inflammation that can cause pigmentary keratitis, including:

  • Entropion – eyelid that rolls inward
  • Ectropion – eyelid that rolls outward
  • Abnormal eyelash position
  • Eyelid tumors or other growths
  • Traumatic injury
  • Chronic, repetitive corneal ulcers
  • Abnormal blink reflexes
  • Previous eye surgery
  • Genetics
  • Dry eye syndrome
  • Glaucoma
  • Autoimmune disease
  • Fungal or bacterial growth
  • Symptoms of Pigmentary Keratitis in Dogs

    The most prominent symptom is a visible pigment deposit within the cornea. Sometimes it can be seen in normal light, or it may need a closer look. It may appear in one or both eyes. Other symptoms that are related to an underlying cause may include:

  • Pain
  • Tearing, with dry-appearing cornea
  • Large, swollen blood vessels in the conjunctiva (white part of eye)
  • Ropy discharge
  • Enlargement of the eye
  • Redness of the conjunctiva
  • Causes of pigmentary keratitis in dogs

    Chronic eye irritation and inflammation are the primary causes of pigmentary keratitis. Conditions that can result in eye inflammation or irritation include:

  • EctropionThe lower eyelid turns outward and leaves the cornea exposed.
  • EntropionThe eyelid rolls inward and the eyelashes scratch the cornea.
  • TrichiasisWhen the eyelashes grow inward and rub against the eye.
  • Dry eye When a dog’s eyes don’t produce enough tears (also known as keratoconjunctivitis sicca or KCS).
  • Eyelid tumors – A mass on the eyelid (both benign and malignant) that can cause inflammation of the cornea.
  • Pigmentary keratitis may also be inherited, and the underlying cause for the condition is not found in all cases.

    A black spot, brown pigment or a black film on your dog’s cornea are all symptoms of pigmentary keratitis. Other symptoms may include:

  • Redness
  • Increased thick, ropey discharge from the eye
  • Cloudy appearance of the eye
  • Pain
  • Excessive tearing
  • Eye enlargement
  • The pigmentation usually appears at the inside corner of the eye and expands to cover the central part of the cornea and the pupil. If most of the eye is covered by the pigmentation, light can’t enter the eye, and your dog may have trouble seeing.

    Many dog owners don’t know about pigmentary keratitis. If your dog has any of these symptoms, take them to your vet as soon as possible.

    Why Do Most Dogs Have Brown Eyes?