Eye Pain in Dogs

Eye disorders are very common in dogs with some disorders being more prevalent with age. It can be easier to determine if your dog has eye pain due to its physical nature and the common symptom of rubbing or pawing at their face. Certain disorders may be extremely painful and need veterinary intervention immediately.

Common Symptoms:

  • Squinting
  • Excessive blinking
  • Redness around the eyes
  • Swelling of the eyes
  • Watery, thick, and/or smelly discharge
  • Keeping eye closed
  • Pawing at the eye
  • Avoiding bright light

Causes of Eyes Pain

Blepharitis

Inflammation of the eyelids in dogs can be caused by a variety of factors, including general skin inflammation, inflammation of the conjunctiva, local glandular infections, or irritants such as plant oils or sunlight. Fungi, mites, or bacteria can infect the eyelids, causing extensive irritation. Blepharitis can be the result of a congenital defect, allergies, bacteria, neoplasia, parasitic infections, traumatic injuries to the eyelid,other eye diseases or completely unknown. Clinical signs include scaly, flaky skin near the eye, intense scratching of the eye, discharge, thickening of the eyelids, loss of hair, loss of skin pigmentation around the affected eye, papule or pustule formation, and inflammation of the cornea which can cause watery painful eyes and blurred vision . Leaving this undiagnosed and untreated can be very painful for the affected dog. To diagnose, vets will take the dog’s full medical history into consideration as well as the timeline of symptom onset. They will then also do physical examination plus a biochemistry profile, urinalysis, and complete blood count.

Treatment:

  • Treatment is dependent on the underlying causes or disease.

Conjunctivitis

Conjunctivitis in dogs, also known as Pink Eye, is a fairly common eye disorder that is the  inflammation of this conjunctiva tissue. The conjunctiva, like the lining of the mouth and nose, is a mucous membrane that covers the eye and eyelid. The conjunctival membranes become red and puffy when conjunctivitis develops. Conjunctivitis can occur for any number of reasons including parasites, allergies, tear film deficiency, viral infections, tumors, eye abnormalities, eye injury/trauma, tear duct obstruction, or irritation from foregin bodies. Dogs who have conjunctivitis will present clinical signs which may often include itching their face/eyes, excessive blinking or squinting, eye pain/discomfort and a clear or green discharge from the eye along with redness in the white of the eye, and the eyelids and surrounding areas being red or swollen. This can create permanent eye damage if left untreated by a vet. A vet will have to determine if conjunctivitis is the primary disorder or secondary to an underlying condition, if there’s damage to the eye and if allergies are involved by doing an ophthalmic examination. An ophthalmic examination includes a physical examination around the eye structures, tear production tests, measurement of intraocular pressure and a corneal stain test.

Treatment: 

Corneal Deterioration

The cornea degenerates as a consequence of lipid deposits within the eye, which might be caused by a hereditary characteristic or an underlying illness. Corneal dystrophy is usually permanent, but corneal degeneration may be alleviated if the underlying disease is addressed. The deposit does not usually cause discomfort, but it can lead to blindness in both situations. Corneal degeneration and corneal dystrophy are both diseases in which lipids build up inside the eye, resulting in a white deposit at the front. The former is usually caused by trauma or an underlying illness, whereas the latter is usually hereditary. Physical signs are shown as a white, opaque deposit in the front of the dog’s eye along with possible eye pain and discomfort. Upon diagnosis, a vet will complete a physical and eye examination along with taking the dog’s medical history into consideration and figure out what other underlying condition there may be.

Treatment:

  • Treatment may be dependent on the underlying cause.
  • Managing pain and discomfort.

Ectopic Cilia

Ectopic cilia are one or more hairs that grow unnaturally through the conjunctiva and into touch with the eye’s surface (cornea). They most often appear on the upper middle eyelid. The invading hairs irritate the cornea, resulting in severe discomfort and corneal ulcers.Clinical signs a dog is suffering from ectopic cilia are general eye pain, severe abnormal ticking or twitching of the eyelid, and excessive tearing and discharge. Diagnoses is done through physical examination and topical anesthetics or sedatives might be used to relieve the discomfort while doing an examination of the tissues surrounding the eye. They will also assess the state of the cornea and if there is a corneal ulceration present by corneal staining.

Treatment:

  • Surgical removal of the offending hairs.
  • Cryosurgery to kill the follicle.
  • Topical ophthalmic antibiotics and systemic pain medications for corneal ulcers.

Entropion

Entropion is an ocular, congenital disorder in dogs that can be quite irritating and painful. It causes the eyelids to roll inwards causing the eyelashes and other surrounding hair to brush against the cornea. The rubbing of the hairs on the cornea can lead to corneal ulceration and once that ulcer is present, it will continue to worsen and can eventually cause scarring on the cornea which can affect vision. The damage can be permanent.  It’s most prevalent in dogs with loose, saggy skin such as Shar Peis and Neopolotin Mastiffs. Other breeds that are predisposed include Boxers, Bulldogs, Chesapeake Bay Retriever, Great Danes, Chow Chows, Saint Bernard and Pugs.Signs a dog may be suffering include squinting, eye pain, eye discharge, tearing, swelling around the eyes, eye redness, rubbing eyes, excessive blinking and corneal ulcers. Quick diagnosis is key before there is permanent damage so if you suspect your dog has entropion or any other eye condition, take them to the vet immediately. Vets diagnose entropion through an eye examination and may perform a fluorescein stain test on the eye to look for corneal damage.

Treatment: 

  • Topical antibiotic ointment may be recommended to prevent infections and lubricate the eyes for mild cases.
  • Surgery to reshape the eyelids for severe cases.

Glaucoma

Glaucoma affects dogs just as much as it affects humans. Glaucoma is a painful disorder of the eye in which an increasing pressure behind the eye, called intraocular pressure (IOP), causes damage to the optic nerve. Signs to look for include hazy or cloudy eyes, redness in the white of the eye, dilated pupils that do not constrict when light hits them, showing signs of pain that include avoiding touching of the head, eyes watering and sleeping more, and also sudden blindness. There are two types of glaucoma:

  • Primary in which the cause is inherited and there are genetic abnormalities in the drainage pathway.
  • Secondary which can be caused by inflammation (uveitis), lens luxation, retinal detachment, tumors, cataracts, or damage to the eye from a ruptured lense.

The type of treatment is dependent on the pain level in the dog, the extent of glaucoma, and whether the dog has fully lost their vision in that eye or not. Certain breeds are predisposed to Glaucoma including (but not limited to) beagle, basset hound, Boston terrier, cocker spaniel, and shar-pei.

Treatments:

  • Drug therapy in the form of osmotic agents, carbonic anhydrase inhibitors, beta-blockers, and prostaglandin analogs.
  • Surgical treatment for dogs with vision includes laser ciliary body cyclophotocoagulation and gonioimplants.
  • Surgical treatments for dogs with lost vision include enucleation, cyclocryotherapy, chemical ciliary body ablation, or intrascleral prosthesis surgery to control pain, therefore improving the quality of life.  

Hyphema

Hyphema is a disorder that may be caused by other conditions such as glaucoma, retinal tears, or uveitis and also may present itself in numerous ways. Ways it may present itself include tiny blood clots in the eye, a redness of the entire eye, or several layers of recurrent hyphema which appear as purple and bright red areas. Other clinical signs of hyphema in dogs include cloudiness of the eye, pool of blood in the irish or cornea, excessive squinting, consistent eye pain, keeping their eye closed, and vision loss. Depending on the cause and severity, Hyphema can either be slightly annoying or very debilitating with secondary complications including adhesions, permanent blurred vision, and blindness. Hyphema is an example that a dog having even slightly red eyes should be taken seriously.

Treatment:

  • Control the bleeding
  • Short-term or life-long use of topical and/or oral medications depending on the underlying cause.

Keratoconjunctivitis Sicca

Keratoconjunctivitis Sicca (KCS) is also known as dry eye. The most common cause of keratoconjunctivitis sicca is a lack of tears or a low quality of tears. Tears are needed for lubrication of the cornea and nutrition as well as removing debris or infectious agents from the eye. It can be caused by an underlying disease which can either be congenital, infectious, neurological, endocrine, a prolapsed gland, radiation near the eye and drug toxicity. Dogs with KCS present painful, red and irritated eyes and they might squint, blink excessively or hold the eyes shut. There might also be a thick, yellowish, mucoid discharge and corneal ulcers. It’s common for dogs to develop hyperpigmentation that looks like a dark film covering the eyes. To diagnose, vets will look at the clinical signs as well as medical history and do a decreased tear production test. They may also test for corneal scarring by corneal staining. Other tests may include intraocular pressure (IOP) to determine if glaucoma is present and tear duct examination or flushing to ensure normal tear drainage.

Treatment:

  • Tear production and tear film replacement ophthalmic medications.
  • Possible surgical correction.

Lens Luxation

Lens luxation or displacement is when the zonules, the thin fibers that hold the lens in place, break down and the lens becomes insatiable and starts to move within the eye. There are different types of luxation of the lens:

  • Posterior luxation: the lens falls backwards but rarely causes discomfort.
  • Anterior luxation: the lens falls forward into the eye and blocks the drainage of fluid from the eye (results in glaucoma or increased intra-ocular pressure (IOP)). This is extremely painful and even causes permanent blindness if not treated quickly.

Lens luxation is often secondary to another eye disorder or it can be hereditary. Other secondary conditions include hypermature cataracts, chronic anterior uveitis, chronic glaucoma, and microphakia. Dogs can also fall into either primary or secondary luxation:

  • Primary luxation: dogs are born with a genetic predisposition, also known as hereditary lens luxation.
  • Secondary luxation: the lens luxation is secondary and caused by another disorder such as uveitis, glaucoma, eye cancer, or trauma

Once a vet has determined if a dog has primary or secondary luxation, they can treat it directly. 

Treatment: 

  • Surgical removal of an anteriorly displaced lens.

Nonulcerative Keratitis

Nonulcerative Keratitis is an inflammatory infection of the cornea that does not retain fluorescein stain, a dye used to diagnose corneal ulcers. The dye will enter the lower layers of the cornea if the top layer of the cornea has been disrupted (as with an ulcer), causing a temporary stain that glows under ultraviolet light; in nonulcerative keratitis, the top layer of the cornea is not disrupted, so no dye enters the lower layers of the cornea. Dogs between the age of four to seven are at increased risk. It causes general eye pain and discomfort. Clinical signs include long-term (chronic) superficial inflammation of the cornea, the cornea loses its transparency as a result of a brown coloration in the eye, dry eye, and general eye discomfort. Eye discomfort can be seen as rubbing their eyes and excessive blinking/squinting in the sun or bright light. If this is suspected, your physical and ophthalmological exam will be conducted which includes blood work, urinalysis, and a biochemistry profile.

Treatment:

  • Radiation therapy for long-term superficial inflammation of the cornea. 
  • Surgical removal of the surface of the cornea for long-term superficial inflammation of the cornea. 
  • Medication in the form of antibiotics, steroids, or immunotherapy drugs.

Sinitus

Also known as sinus congestion or infection, sinusitis is when inflammation and mucus cannot drain out of the body. Sinus infections can be caused by a number of things including, but not limited to, weakened immune system, cancer, polyp, foreign body in the sinuses or nasal cavity, dental problems, oronasal fistula, or parasites. Symptoms that your dog is struggling with a sinus infection include sneezing, watery eyes, gaging, pain due to the pressure in the forehead and around the eyes, sneezing/coughing, sits with head hung and eyes partially closed, and swelling below the eyes. To determine whether your dog has sinusitis, the vet will usually start with a physical exam in which they will look for signs of tooth root abscesses and ulcers. A dental test, a blood examination, imaging, and a physical examination may be carried out to assess the root cause of the inflammation and establish a successful recovery course. 

Treatments:

  • Humidifier to loosen mucus.
  • Antibiotics for a bacterial infection.
  • Medication as appropriate to treat the underlying cause.

Ulcerative Keratitis

Ulcerative keratitis is an inflammatory condition that affects the cornea of the eye. Ulcerative keratitis is inflammation of the surface tissue, the corneal epithelium, which causes erosion of the surface tissue, but it can also advance into the deeper tissue, the corneal stroma, resulting in a corneal ulcer. There’s often an underlying disorder causing Ulcerative Keratitis including eye trauma, inability to completely close the eye, abnormal tear production or quality, eye infections, and other diseases of the corneas, eyelids, or tear-producing glands. The disorder can be irritating and slightly painful and affected dogs may show signs of excessive blinking or squinting, rubbing their eyes, and have whitish/green discharge from the eyes. Dogs may avoid strong light or, in its presence, have spasmodic blinking. The tissue around the eye may grow swollen and red, and you’ll see a divot in the eye’s surface. If the keratitis has been present for some time, blood vessels or pigment may appear in the region surrounding the corneal lesion as well as fluid buildup in the cornea’s deeper tissues can also cause the cornea to become cloudy. You may be referred to an ophthalmologist by your primary veterinarian for official diagnoses where they will look at the clinical signs and perform an eye examination which includes checking the eye interior, a pupillary light reflex test, and a dazzle reflex test. In the case of suspected ulceration, they might perform a fluorescein eye test.

Treatment:

  • Treatment is dependent on the underlying cause as well as how long it’s been present and the extent of the damage.
  • Antibiotic ointment or drops. 
  • Surgical treatment to remove loose surface cells once the surface of the eye or repair any corneal ulcers. 

Uveitis

Uveitis occurs when one or more of the uvea’s structures become inflamed. True uveitis or pan-uveitis refers to inflammation that affects all three components. Anterior uveitis occurs when just the ciliary body and iris are inflamed, whereas posterior uveitis occurs when the choroid is affected. Uveitis can be the result of any number of underlying conditions including different types of infections, a metabolic disease like diabetes, high blood pressure, immune disorders, eye trauma, lens damage and toxins. One of the main clinical signs are severe eye pain and discomfort with intense reddening and clouding of the eye. Dogs will usually keep their eyes shut and avoid bright light. Other physical symptoms may include bleeding into the eye, constricted pupil, bulging iris, blood or pus in the anterior chamber of the eye along with cataracts, blindness or lens displacement in severe cases.

Treatment: 

  • Topical eye medications such as corticosteroids to reduce inflammation and provide pain relief.
  • NSAIDs.
  • Repair any corneal tears or removal of a foreign body in the eye for uveitis caused by trauma.