VISION AND BLINDNESS IN DOGS

Many pet owners and their families have a misunderstanding as to how well blind dogs function as pets. Many researchers have studied the effects of blindness in dogs. They found no evidence that size or breed of the dog had any bearing on how well the dog coped with blindness. Their research provided evidence that with time and proper education of the pet owner, most blind dogs, and their owners adapt well to the loss of the pet's vision.

The Animal Ophthalmology Center contends with blind pets and their owners on a daily basis. Our personal experiences with blind dogs have been very encouraging. In order to help you adjust to owning a blind dog we would like to make you aware of a few important points concerning blindness.

Dogs that go blind suddenly (such as those with Sudden Acquired Retinal Degeneration [SARD] or retinal detachment) require a longer period of time to adapt and adjust to loss of vision. There will be a longer period of adjustment for the dog and the owner when vision is suddenly lost.

Dogs that go blind more slowly over an extended period of time (such as those that have Progressive Retinal Atrophy [PRA]) adapt more easily. Oftentimes the owner doesn't know that the dog has lost all vision because the dog functions remarkably well in a familiar environment despite the loss of vision. The dog usually adjusts more each day with progressive loss of vision. The psychological adjustment for an owner that is unaware that their dog is progressively losing vision over time, or that their dog is blind, can be difficult. However, the quality of life is exceptional for most blind dogs once the dog has adapted to being blind.

When sudden blindness or progressive loss of vision is associated ocular diseases that are painful (glaucoma, uveitis), the animal may not master simple tasks in their environment because pain may impede their ability to adapt to blindness. Owners of blind animals that have painful eye disease attribute a pet's inactivity to the blindness when in fact the inactivity is most frequently due to ocular pain. Treatment to alleviate ocular pain is critical and may consist of medical or surgical intervention.

Some dogs are blind secondary to a systemic disease process (a disease that affects different organ systems or the entire body) that also affected the eyes (diabetes mellitus, systemic hypertension/high blood pressure.) In such instances a blind dog may not adapt well until the systemic disease is treated.

A frequent and unfortunate misconception is that it is cruel and inhumane to keep a blind dog. It is our responsibility as veterinary ophthalmologists to make you aware of how well a blind dog can function as long as there is no ocular pain and as long as an owner is conscientious about living with a blind dog. Blind dogs function very well in a familiar environment for several reasons. Dogs do not rely on their sense of vision to the same extent as do humans. The dog's vision is also not as highly developed as it is in humans. Dogs also cannot focus well on near objects, are partially color blind, and have poor detail vision. Canine vision is superior to human vision for detecting moving objects in dim light. This vision suits their original need as nocturnal hunters. Since the majority of domesticated dogs no longer hunt to survive, blindness does not interfere with their domesticated primary function--being a companion and pet.