How to tell if a dog is going blind? Dog behaviorists tell us that dogs use their eyes not only for seeing but also to communicate their moods and emotions to other animals. Dogs’ eyes look similar to human eyes but they differ in several ways: they are more flattened, the lens is not so flexible when it comes to shape changes and they are more sensitive to light and movement. Dogs also have poorer near vision, but better peripheral vision. A dog’s eyes should be bright, shining and free of debris and discharge. Unfortunately, the eyes are particularly sensitive and delicate. A plethora of conditions may damage the eyes and eventually lead to impaired vision or even complete blindness. Here's how to tell if a dog is going blind.
Acknowledge Common Causes of Blindness in Dogs
Generally speaking, reduced or lost vision may have both inherited and acquired causes. The primary cause may be either in the eye itself or in the brain. Common causes of blindness in dogs include the following conditions:
When the proteins in the lens become cloudy, the lens loses part or all of its transparency. The affected area, called cataract, may become mildly foggy or completely opaque. This problem may affect only part of the lens or may fill it completely.
Cataract usually develops as a result of inheritance, trauma or metabolic disease (particularly diabetes). Hereditary juvenile cataract occurs in over 80 breeds including the Boston Terrier, Golden Retriever, Labrador Retriever, Cocker Spaniel, Miniature Schnauzer, West Highland Terrier, Siberian Husky and Old English Sheepdog.
Surgery will be considered if the dog is blind or on the verge of blindness. However, surgery is only undertaken when it is likely to restore or significantly improve the vision.
Although the fluid contents of the eye seem fixed, as if in a balloon, there is actually a slow, continual exchange of fluid from inside the eye into the general circulation. Normally the production and drainage of fluid are balanced. If, however, fluid is produced faster than it can leave the eye, the fluid pressure builds up inside the eye. This condition is known as glaucoma.
The increasing pressure of the fluid inside the eyeball causes a great deal of pain, a fixed stare and a clouding of the eye. As the eye continues to bulge, tears stream out and blood vessels expand. In addition of being painful, the increasing pressure damages the retina and optic nerve, eventually leading to impaired vision and blindness.
Early and immediate treatment is vital if the sight of the eye is to be saved. If possible, laser surgery is highly recommended.
- Progressive retinal atrophy (PRA)
This common inherited condition is recognized in more than 90 breeds. In PRA retinal cells die and the blood vessels in the choroid layer shrivel. As a result, the vision gradually deteriorates.
The first sign of diminished sight is usually night blindness. As PRA grows worse, a lack of confidence becomes obvious whenever the affected dogs tries to jump down or walk down stairs. Eventually, the entire retina dies and the eye goes blind. Unfortunately, at the moment there is no known treatment for PRA.
- Suddenly acquired retinal degeneration syndrome (SARDS)
It is not well-determined why and how SARDS develops. However, it is postulated that the condition has autoimmune origin. SARDS is particularly common among female, middle-aged dogs from the certain breeds like the Brittany Spaniel, Bichon Frise, Maltese, Pug, Miniature Schnauzer and Dachshund.Affected dogs become completely and permanently blind very quickly, in a matter of weeks and sometimes even days. Sadly, there is no known cure for SARDS.
- Injuries and infections
If left untreated, injuries and infections of the eye can easily lead to permanent damage of the eye structures and impaired vision. If damaged beyond repair, a glaucomatous, infected or injured eye is best removed to prevent continued pain or further injuries and complications. Removing an eye may sound terrible, but it makes the dog much more comfortable and once hair grows, is aesthetically acceptable.
Watch For Signs of Vision Loss in Dogs
Never ignore any visible changes in your dog’s eyes. Cloudiness may indicate irreversible degeneration. Bulging is an important sign because it indicates glaucoma which must be caught early to be treated successfully. In addition, an obvious change, such as clouding, may lead owners to overlook more subtle changes.
Usually it is easy to assume that the eye looks different because it is becoming cloudier or that the dog is staring because its sight is naturally deteriorating with age. Regular veterinary checks with proper diagnostic tools are vital.
How to Tell if a Dog is Going Blind
A dog that has gradually become blind may remain perfectly confident on its own, well-memorized territory. You can easily find out the extent of the blindness by conducting a sight test on your dog.
All you need to do is to slightly rearrange the furniture in a room with which your dog is familiar and then darken the room. Allow your dog to come in and observe what happens. Repeat this test with the lights on.
A completely blind dog will do no better with the lights on than in the darkened room, while a partially sighted dog is more confident when the light is good. Shining a light in your dog’s eye may cause the pupil to constrict but this reaction, in itself, does not mean it can see, let alone see well.
How a dog handles blindness varies not only with its own personality, but also with that of its owner. Some dogs and owners cope well with blindness and others do not. A confident dog may be willing to continue such activities as jogging with its owners and playing tug-of-war and other games, while a less confident dog may turn in on itself and seem to lose interest in life.
The ultimate decision on how to manage a blind dog is one that only you, your dog and your trusted vet can answer. It goes without saying that taking care of a blind dog requires special effort. However, our beloved canine babies are totally worth it.
"It is important to understand that your pet’s blindness is likely much harder on you than it is for your pet. Your pet can sense your emotions, so it is important to stay positive and treat your furry family member the same way you did before the blindness."~DJ Haeussler, veterinary ophthalmologist
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia.
She currently practices as a veterinarian in Bitola and is completing her postgraduate studies in the Pathology of Domestic Carnivores at the Faculty of Veterinary Medicine in Zagreb, Croatia.
Ivana’s research has been published in international journals, and she regularly attends international veterinary conferences.