Disorder - PRA Rod Cone Dystrophy Type 2

Organ Systems Involved
Nervous/sensory

Alternative Names
Rod Cone Dysplasia Type 2

Brief Description

This disorder is an early onset form of Progressive Retinal Atrophy that affects the retina of the eye. The retina contains the light-sensitive part of the eye that collects visual information and sends it via the optic nerve to the brain. The disease affects both eyes and dogs eventually become blind.

Presenting Signs

The initial symptoms of this disease usually occur in the first year of life. As the retina degenerates, the dog will find it hard to see in the dark. This symptom is known as night blindness and may go unnoticed, as dogs are less reliant on vision than humans and so can adapt quickly if their surroundings are familiar to them. Keen observers may notice their dog losing its way in the dark, or bumping into objects that are not in their usual place. Affected dogs may also be afraid to enter dark rooms or to move around outside at night. As the disease progresses, the dog will eventually lose all vision, even in bright light. The appearance of the eye does not change until the disease reaches an advanced stage. As the dog becomes completely blind, the pupils do not respond to light by contracting in the normal way, and they become very large. At this stage the eyes may become more reflective of light, however, this may be difficult for an untrained person to detect. In advanced stages, cataracts may form on one or both eyes giving them a cloudy appearance.

Related Disorders

Cataracts

PubMed References
PRA Rod Cone Dystrophy Type 2

Further Reference Material [OMIA Number]
1260


Contributor
Peter White