Eyes diseases

• Ectropion (eyelid folding outward) is a common condition in dogs, usually affecting the lower lid. Breeds associated with ectropion include the Cocker Spaniel, the St. Bernard, the Bloodhound, and the Basset Hound.
  
• Entropion (eyelid folding inward) is a common condition in dogs, especially the Chow Chow, Shar Pei, St. Bernard, and Cocker Spaniel. Upper lid entropion involves the eyelashes rubbing on the eye, but the lower lid usually has no eyelashes, so hair rubs on the eye. Surgical correction is used in more severe cases.
  
• Distichia (including ectopic cilia) is an eyelash that arises from an abnormal spot on the eyelid. Distichiae usually cause no symptoms because the lashes are soft, but they can irritate the eye and cause tearing, squinting, inflammation, and corneal ulcers.
  
• Chalazion is a granuloma that forms in the eyelid due to blocked secretions from the Meibomian gland. Inflammation of the eyelid may result.
  
• Trichiasis in dogs is hair from the eyelid growing in the wrong direction and rubbing on the eye, causing irritation. It usually occurs at the lateral upper eyelid, especially in the English Cocker Spaniel.
  
• Cataracts are an opacity in the lens of the eye. Most cataracts in dogs are caused by a genetic predisposition, but diabetes mellitus is also a common cause. The only effective treatment is surgical removal.
  
• Lens luxation is a displacement of the lens from its normal position. Terrier breeds are predisposed.
  
• Nuclear sclerosis is a consistent finding in dogs greater than seven years old. Nuclear sclerosis appears as a bilateral bluish-grey haziness at the nucleus, or center of the lens. Many people get this confused with Cataracts, and that is not the case. Many people also think the dog loses its vision, but the dogs can actually see quite well.
  
• Progressive retinal atrophy (PRA) is a genetic disease of the retina that occurs bilaterally and is seen in certain breeds of dogs. It causes progressive vision loss culminating in blindness.
  
• Retinal dysplasia is an eye disease affecting the retina of dogs. It is usually a nonprogressive disease and can be caused by viral infections, drugs, vitamin A deficiency, or genetics. Retinal dysplasia is characterized by folds or rosettes (round clumps) of the retinal tissue.
  
• Sudden acquired retinal degeneration (SARD) is a disease in dogs causing sudden blindness. It can occur in any breed. The cause is unknown, but possibly involves either autoimmune disease, a toxin, or Cushing's disease. Symptoms include sudden permanent blindness, dilated pupils, and loss of the pupillary light reflex.
  
• Retinal detachment is caused in dogs by genetic disorders such as retinal dysplasia or Collie eye anomaly, trauma, inflammation or cancer. Reattachment may occur spontaneously or with medical or surgical therapy.
  
• Corneal dystrophy is a condition characterized by bilateral, noninflammatory opacity of the cornea. It appears as grayish white lines, circles, or clouding of the cornea. Corneal dystrophy can also have a crystalline appearance.
  
• Corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. They are caused by trauma, detergent burns, and infections. Other eye conditions can cause corneal ulcers, such as entropion, distichia, corneal dystrophy, and keratoconjunctivitis sicca.
  
• Florida keratopathy an eye condition characterized by the presence of multiple spots within both corneas. In the United States, it is found most commonly in the southeastern part of the country.
  
• Pannus is a form of superficial keratitis, or inflammation of the cornea, found most commonly in German Shepherd Dogs, Greyhounds, and Siberian Huskies.
  
• Collie eye anomaly (CEA) is a congenital, inherited, bilateral eye disease of dogs involving the retina, choroid, and sclera. It can be a mild disease or cause blindness. It is known to occur in Smooth and Rough Collies, Shetland Sheepdogs, Australian Shepherds, Border Collies, and Nova Scotia Duck Tolling Retrievers.
  
• Cherry eye is the term used to refer to canine nictitans gland prolapse, a common eye condition in various dog breeds where the gland of the third eyelid prolapses and becomes visible.
  
• Glaucoma is an increase of pressure within the eye. It is a common condition in dogs. It can be caused by abnormal development of the drainage angle of the eye, lens luxation, uveitis, or cancer. Cocker Spaniels, Poodles, and Basset Hounds are predisposed.
  
• Ocular Melanosis (OM) is a disease of the eye which in dogs is almost found exclusively in the Cairn Terrier. The disease is caused by an increase of melanocytes in the iris, sclera, and surrounding structures.
  
• Keratoconjunctivitis sicca (dry eye) is common in dogs. Symptoms include eye redness, a yellow or greenish discharge, ulceration of the cornea, pigmented cornea, and blood vessels on the cornea.
  
• Vogt-Koyanagi-Harada syndrome is a condition seen in dogs characterized by uveitis (inflammation of the inside of the eye), poliosis (whitening of hair), and vitiligo (loss of pigment in the skin).
  
• Conjunctivitis is inflammation of the conjunctiva. In dogs it is most commonly caused by mechanical irritation (such as by entropion, ectropion, or trichiasis), allergies, and keratoconjunctivitis sicca. Any bacterial infection is usually secondary.
  
• Eye proptosis is a condition resulting in forward displacement and entrapment of the eye from behind by the eyelids. It is a common result of head trauma in dogs. Most commonly it occurs in brachycephalic (short nosed) breeds.
  
• Horner's syndrome results from damage to the sympathetic innervation of the eye. Signs include enophthalmos (sunken eye), miosis (small pupil), elevated third eyelid, and ptosis (drooping of the upper eyelid]]. Usually the syndrome in dogs is idiopathic, but it can also be caused by trauma, tumors, or ear infections.
  
• Optic neuritis is inflammation of the optic nerves. In dogs this is most commonly caused by granulomatous meningoencephalitis or infection.
  
• Persistent pupillary membrane is a condition of the eye involving remnants of a fetal membrane that persist as strands of tissue crossing the pupil.
  
• Uveitis is inflammation within the eye. Anterior uveitis (inflammation of the iris and ciliary body) is most common in dogs. The disease is usually immune-mediated in dogs, but may also be caused by trauma, cataracts, infectious canine hepatitis, leptospirosis, ehrlichiosis, or systemic fungal infections.
  
• Asteroid hyalosis is a degenerative condition of the eye involving small white opacities in the vitreous humor. The cause is unknown.
  
• Synchysis scintillans is a degenerative condition of the eye resulting in liquified vitreous humor and the accumulation of cholesterol crystals within the vitreous.
  
• Iris cysts are small hollow structures either attached to the iris of the eye or floating free in the anterior chamber.
  
• Imperforate lacrimal punctum is a congenital disorder of dogs involving the lack of an opening to the nasolacrimal duct (tear duct) in the conjunctiva.
  
• Exophthalmos is a normal condition in brachycephalic (short nosed) dog breeds because of the shallow orbit. However, it can lead to keratitis secondary to exposure of the cornea.