What Causes Sudden Blindness in Older Dogs?

Blindness can occur in dogs (and cats) and this can seem scary to both us and our pets. Here is some information to help navigate the process to keep our pets comfortable and happy.

Blindness is usually not detected until both eyes are affected because dogs are typically able to adapt with the healthy eye.

Blindness can be slowly progressive or have a sudden onset. Sometimes it has set on over time but seems very sudden to us. We may not see trouble at home but when our blind dog is in a new setting he may walk along the wall, lean against his owner, or even bump into things.

Blindness can be temporary or permanent. It is important to work with your veterinarian to get more information about your pet’s specific reason for blindness.

Some causes of blindness can be located directly at the eyes, others can be systemic or affecting other parts of the body as well as the eyes.

Below are some common causes of blindness in dogs.

· Infections or Inflammation (Viral, bacterial, fungal)

· Cataracts (Can be caused by diabetes mellitus, toxins, genetics, as well as other diseases)

· Glaucoma

· Retinal detachment (Can be caused by high blood pressure, kidney failure, or other diseases)

· Trauma

· Sudden Acquired Retinal Degeneration Syndrome (SARDS)

Today, we are going discuss SARDS more specifically. This is a permanent blindness that comes on suddenly in our pets.

Dogs Affected by SARDS

SARDS is most often diagnosed in older animals. The median age for the condition is 8.5 years. Dachshunds and Miniature Schnauzers are particularly afflicted. Pugs, Brittany Spaniels, and Maltese are other breeds that show a predisposition for the condition. Sixty to seventy percent of the dogs with the condition are female. Interestingly, one study found that 46 percent of SARDS cases were diagnosed in the holiday months of December and January.

Cause of SARDS in Dogs

The cause and retinal changes of SARDS are unknown and poorly understood. The cells of the rods and cones of the retina suddenly undergo programed cell death or apoptosis. Inflammatory, autoimmune, or allergic causes, although suspected, have not been confirmed. The lack of inflammation associated with the condition and the poor response to treatment as an immune related disease suggest a non-immune related cause.

Symptoms of SARDS in Dogs

Prior to blindness, many dogs will show navigation difficulty around the house and yard. They may bump into things or show caution in movement. Blindness is considered permanent, although some owners of younger dogs stricken with the condition report intermittent sight. Because blind dogs quickly accommodate to vision loss, these observations may not reflect actual recurrence of vision.

Forty to fifty percent of dogs with SARDS also have increased water consumption, increased urination, increased food consumption, and weight gain. These symptoms persist after the onset of blindness, especially the change in food consumption. Because these are the same symptoms associated with a hormonal condition called hyperadrenocorticism, or Cushing’s disease, a link with SARDS was speculated. Actually, studies indicate that few SARDS patients have Cushing’s.

Living With a Dog Affected With SARDS

A recent survey of owners of dogs affected with SARDS indicates that owners perceive the quality of their dogs' life as good. Of the 100 dogs represented in the survey, only nine owners reported that they thought their dogs' quality of life was poor. Owners also reported that navigation abilities in both the house and the yard were moderate to excellent. Forty percent of owners reported moderate to excellent navigation even in new and unfamiliar surroundings.

Many dogs can adapt well and utilize their other senses better. Some dogs relay on other pets/housemates to keep them informed. Do be careful around the house and yard with stairs, electric cords, swimming pools, and areas where pets can get stuck or confused.

Books and information are available to help increase your dog’s quality of life living with blindness. “Living With Blind Dogs” by Caroline D. Levin is a helpful resource to teach you and your dog new cues using his other senses.