Cataract refers to the condition when the eye lens is partially or completely clouded preventing light to pass to the retina causing loss of vision. Mostly this condition in dogs is inherited and Miniature poodles, American cocker spaniel, miniature schnauzer, golden retrievers, Boston terriers, and Siberian huskies are predisposed to cataracts.
Cataract may also be related to diabetes mellitus in which case symptoms of diabetes like increased thirst, increased frequency of urination and weight loss may be observed along with vision impairment.
Cataract is a progressive disorder that if not treated quickly may lead to blindness in one or both eyes. This is especially the case with diabetes mellitus-related cataracts because they progress very rapidly in dogs. Symptoms vary depending on the degree of vision impairment. Usually less than 30 percent lens opacity is asymptomatic while more than 60 percent opacity may cause loss of vision or have difficulty seeing in dimly lit areas.