Blindness in Dogs & Cats. - www.ipohvet.com

Blindness in Dogs & Cats. - www.ipohvet.com: "PDF Print E-mail Blindness in veterinary ophthalmology: examination, causes and treatment I. EXAMINATION OF THE BLIND ANIMAL 1. History a) Is the blindness of sudden onset, or gradual onset? o Frequently, owners will report sudden onset blindness, even though the results of the ophthalmic examination will reveal changes associated with chronic, long standing disease. Careful questioning will reveal that the blindness was noticed when the animal's environment was changed (visiting friends, moving to a new house). We can assume that even though the animal has been blind for a long time, the gradual onset of the disease enabled it to learn to navigate in a familiar environment. The change in environment will cause it to bump into objects, misleading the owners into believing that the blindness is acute. b) Was deterioration of vision associated with preferential loss of night vision or day vision? o One of the first behavioral signs of inherited, degenerative diseases of the outer retina (commonly known as Progressive Retinal Atrophy) is loss of night vision (nyctalopia) as rods are affected before cones. Be careful of how you phrase the question!! Do not 'lead' the owners. Other rod functions (such as detection of moving objects, or objects in the peripheral visual "