What Causes Sudden Blindness in Older Dogs?

By Ken Tudor, DVM on Dec. 5, 2013
What Causes Sudden Blindness in Older Dogs?

Reviewed and updated on May 19, 2020 by Amanda Simonson, DVM

Blindness can occur in dogs, and it can seem scary, especially when it happens suddenly. Here’s some information to help you navigate the situation and keep your pet comfortable and happy.

Sudden Blindness in Dogs

Blindness in dogs can progress slowly or have a sudden onset. However, in some cases, blindness that may have occurred over time can appear to be sudden to us upon diagnosis.

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

Since a dog is so used to their home surroundings, pet parents may not notice that their dog’s vision is deteriorating. It’s not until the dog is navigating a new environment that pet parents see signs of blindness, such as:

  • Walking along the wall

  • Leaning against their owner

  • Bumping into things 

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

What Causes Blindness in Dogs?

Some causes of blindness are the result of issues within the eye, while others can be systemic or affect other parts of the body as well as the eyes.

Here are some common causes of blindness in dogs:

  • Infections or Inflammation (viral, bacterial, fungal)

  • Cataracts (can be caused by diabetes mellitus, toxins, genetics, or other diseases)

  • Glaucoma

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

  • Trauma

  • Sudden acquired retinal degeneration syndrome (SARDS)

What Is SARDS?

SARDS is a permanent form of blindness that occurs suddenly. It’s most often diagnosed in older dogs, with the median age being 8.5 years, and 60-70% of dogs with the condition are female.

Dachshunds and Miniature Schnauzers are particularly afflicted. Pugs, Brittany Spaniels, and Maltese breeds also show a predisposition for the condition.

Cause of SARDS in Dogs

The cause and retinal changes associated with 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 have been suspected but not confirmed. The lack of inflammation associated with the condition and the poor response to treatment as an immune-related disease suggest a nonimmune-related cause.

Symptoms of SARDS in Dogs

Prior to blindness, many dogs will have difficulty navigating around the house and yard. They may bump into things or show caution in their movements.

About 40-50% 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.

Since 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.  

What’s the Quality of Life for a Dog Affected With SARDS?

survey of owners whose dogs are affected with SARDS indicates that the majority perceive the quality of their dog’s life as good.

Owners also reported that their dog’s ability to navigate both the house and the yard were moderate to excellent. And 40% of owners reported moderate to excellent navigation even in new and unfamiliar surroundings.

Of the 100 dogs represented in the survey, only nine owners reported that they thought their dog’s quality of life was poor.

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

Dr. Ken Tudor

Featured Image: iStock.com/kacoates


Ken Tudor, DVM


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