Progressive vision loss in any dog in the absence of canine glaucoma or cataracts can be an indication of<unk> . It usually starts with decreased vision at night, or nyctalopia. Other symptoms include dilated pupils and decreased pupillary light reflex. Fundoscopy to examine the retina will show shrinking of the blood vessels, decreased pigmentation of the nontapetal fundus, increased reflection from the tapetum due to thinning of the retina, and later in the disease a darkened,<unk> ed optic disc. Secondary cataract formation in the posterior portion of the lens can occur late in the disease. In these cases diagnosis of<unk>  may require electroretinography (ERG). For many breeds there are specific genetic tests of blood or buccal mucosa for<unk> . Absent a genetic test, animals of breeds susceptible to<unk>  can be cleared of the disease only by the passage of time—that is, by living past the age at which<unk>  symptoms are typically apparent in their breed. Breeds in which the<unk>  gene is recessive may still be carriers of the gene and pass it on to their offspring, however, even if they lack symptoms, and it is also possible for onset of the disease to be later than expected, making this an imperfect test at best.
Progressive retinal atrophy
Intraretinal microvascular abnormalities
Hypotony maculopathy
Progressive outer retinal necrosis
Macular scarring
Optic disc pallor
Punctate inner choroiditis
Macular sparing