There are several hereditary eye conditions that can affect dogs. Here are a few common examples:
1. Progressive retinal atrophy (PRA): This is a group of inherited disorders that cause the cells in the retina (the light-sensitive layer of tissue at the back of the eye) to deteriorate. PRA leads to progressive vision loss over several months or years, with night vision being affected first. Several breeds are affected, most commonly Poodles, Labradors and Cocker Spaniels.
2. Retinal Pigment Epithelial Dystrophy (RPED): this is a hereditary and progressive condition which affects the retinal pigment epithelium, the outermost layer of the retina, and can lead to vision impairment later on in life. Affected dogs can show impaired vision in bright light at first and see better in dim light, and eventually lose the central field of vision, although they rarely become fully blind. Affected breeds include Collies, Briards, Spaniels and Corgies.
Glaucoma
3. Glaucoma: This is a condition in which the pressure inside the eye becomes too high, damaging the optic nerve and retina and leading to vision loss often in a very short time. Glaucoma can be inherited or acquired. Several breeds are affected by different forms of glaucoma, most commonly Basset Hound, Siberian Husky, Spaniels, Hungarian Viszla, several terriers (especially the Dandie Dinmont)
4. Cataracts: These are cloudy areas in the lens of the eye that can cause vision impairment, when the opacity is mild or localised, or blindness. Cataracts can be inherited or acquired, and breeds affected by the hereditary form, such as Labrador and Golden Retrievers, Poodles, Schnauzers and several others, should be screened before breeding.
Cherry eye
5. Cherry eye: This happens when the tear producing gland at the base of the third eyelid prolapses and due to exposure becomes red and swollen. Cherry eye often has a familial predisposition, with some breeds such as English and French bulldogs being more represented than others, although the condition can affect any individual.
6. Retinal dysplasia: This is a congenital malformation of the retina that, in its worst form, can cause vision loss or blindness in puppies. Retinal dysplasia can be inherited or acquired. Several breeds are affected, including Labrador and Golden Retriever, Spaniels, Rottweilers, Bedlington terrier, Hungarian Puli
7. Entropion: This occurs when the eyelids roll inwards, causing the hairs to irritate the surface of the eye. Common symptoms of entropion are squinting, pain and corneal ulcer formation. Some breeds such as Shar Pei, British Bulldogs, Chows, Saint Bernards are often predisposed to this condition, but also Labradors and Rottweilers are commonly affected.
8. Entropion/Ectropion: while entropion is an inward rolling of the lids, ectropion is lid laxity and “droopiness” of the lower lids. Some dogs are affected by a combination of the two conditions and the lids are severely distorted, in a condition known as diamond eye, which can cause pain and ulcers. Giant or heavy breeds such as St Bernard, Newfoundland, Neapolitan Mastiff are mostly affected, but also breeds with heavy folds and skin, such as the Basset Hound.
9. Ectopic Cilia and Distichiasis: this is where eye lashes (cilia) grow on the inside of the eyelid (ectopic cilia) or on the eyelid margin (distichia), in places they shouldn’t. Similarly to entropion, the presence of these cilia rubbing on the cornea causes pain, redness, excessive
blinking and tear production and often corneal ulcers. Breeds such as Shih Tzu, Cocker Spaniel, Poodles, Terriers and Bulldogs are more commonly affected by these c
Lower lid Entropion
onditions.
10. Primary Lens Luxation: this happens when the support ligament which holds the lens in place inside the eye breaks down due to an inherited defect, causing the lens to dislocate from its normal position. This leads to acute pain and visual loss, especially if accompanied by an increase in intraocular pressure, and should be treated as an emergency. Primary lens luxation is a familial problem in several terrier breeds, especially Jack Russells,
11. Collie Eye Anomaly: this is a congenital and hereditary condition affecting all collie breeds characterised by abnormal development of the retina, choroid and sclera (the wall of the eye). The condition can manifest in variable forms and can lead to blindness in its most severe forms, although many affected dogs do not show visual impairment.
Distichiasis
12. Optic Nerve Hypoplasia. This is a congenital condition in which the optic nerve does not develop properly and vision is affected from birth. The condition can be unilateral or bilateral and can be inherited in Miniature Poodles.
13. Persistent Hyperplastic Primary Vitreous (PHPV): this is a congenital and hereditary disorder in which the vascular network which feeds the eye during development fails to regress and clear as it should, leaving more or less patent vessels between the lens and the retina. The condition can affect vision and potentially lead to bleeding inside the eye. Affected breeds include Staffordshire Bull terrier, Dobermann, Miniature Schnauzer, Siberian Husky, Basset Hound.
If you are concerned about the potential for hereditary eye conditions in your dog, it is a good idea to have them evaluated by a veterinarian and discuss any potential concerns with a responsible breeder before purchasing a puppy. Regular eye exams can also help detect any issues early on and allow for timely treatment