Fast facts on SARDS from Dr. Buzby
- Dogs with SARDS experience sudden and irreversible blindness because the photoreceptors (i.e. cells in the eye that help convert light into an image) stop working.
- In addition to rapidly becoming blind, dogs with SARDS may also drink more water, urinate more often, gain weight, or lose their sense of smell.
- Unfortunately, there is no treatment for SARDS.
- Most dogs with SARDS adjust well to being blind and have a good quality of life.
When Madeline, an 8-year-old overweight spayed female Dachshund, came in for an appointment, her mom was understandably distressed. Seemingly overnight, Madeline had started bumping into furniture and acting like she couldn’t see. Plus, she was drinking a ton of water, urinating frequently, and acting hungry all the time.
As I examined Madeline and listened to her mom talk, one condition was in the forefront of my mind—SARDS or sudden acquired retinal degeneration syndrome. All the exam findings plus her symptoms, breed, and age made her a textbook case.
What is SARDS in dogs?
Sudden acquire retinal degeneration syndrome (SARDS) is a condition that causes complete blindness over a matter of days to weeks. The exact cause is unknown, although researchers speculate it could be a neuroendocrine (hormone-related) or autoimmune disease. But what we do know is that it occurs when all the photoreceptors in the eye suddenly stop working.
Normally, the photoreceptors (e.g. rods and cones) in the retina have the very important job of taking the light that enters the eyes and turning it into nerve signals. Then the signals travel up the optic nerves to the brain, where the brain perceives the image the dog is seeing.
But when the photoreceptors malfunction in SARDS, they aren’t generating nerve signals. Therefore, the brain isn’t getting any information about the image. Practically speaking, this means the dog cannot see.
What are the symptoms of SARDS in dogs?
Unsurprisingly then, the most common clinical sign associated with SARDS is rapid loss of vision that is not painful. These pups are completely blind and will suddenly start bumping into objects. SARDS patients will avoid going down flights of stairs or may be reluctant to move. And some can appear disoriented or more anxious than usual.
However, up to 85% of dogs with SARDS can also have symptoms that resemble those of a different illness—Cushing’s disease in dogs (i.e. an excess of the steroid hormone cortisol). SARDS and Cushing’s disease can share these symptoms:
- Lethargy in dogs
- Weight gain
- Increased urination (i.e. polyuria)
- Increased thirst in dogs (i.e. polydipsia)
- Increased appetite (i.e. polyphagia)
- Enlarged liver (i.e. hepatomegaly)
Plus, a 2023 article in Veterinary Ophthalmology demonstrated that dogs with sudden acquired retinal degeneration syndrome have a significantly decreased sense of smell compared to sighted dogs and dogs who were blind from causes other than SARDS.
How is SARDS diagnosed?
Whether you only notice acute blindness or your dog is showing some of the other symptoms too, a vet visit is in order. During the appointment, the vet will carefully examine your dog from nose to tail, paying special attention to your dog’s eyes.
Typically, dogs with SARDS have dilated pupils that constrict slowly or incompletely or do not constrict at all in response to light. Initially, the fundus (i.e. inside surface of the back of the eye) looks normal, but eventually the vet may see evidence of retinal degeneration.
Gathering a history
In addition to examining your dog, the vet will also ask questions about your dog’s history. For example, a toxic plant called the Arabian starflower (Ornithogalum arabicum) can cause irreversible blindness in dogs. So your vet may want to know if your dog could have come in contact with it recently.
Also, the vet may ask questions about the timeframe in which your dog became blind. This information can help distinguish conditions like SARDS that cause rapid-onset blindness from those like progressive retinal atrophy (PRA), where the dog becomes blind more gradually and loses night vision first.
Considering the dog’s breed, age, and sex
Most likely, your vet will also take your dog’s breed, age, and sex into consideration when deciding how likely it is your dog has SARDS.
The majority of SARDS patients are middle-aged to older female dogs, particularly those who are spayed and/or moderately overweight. However, male dogs can also develop SARDS.
While any breed or mixed breed can be affected, SARDS occurs more commonly in the following dog breeds:
- Bichon Frise
- Brittany Spaniel
- Cocker Spaniel
- Miniature Schnauzer
- Shih Tzu
If the vet suspects SARDS based on your dog’s history, exam findings, symptoms, breed, and age, the next step will be to send your dog to a veterinary specialist near you, namely a veterinary ophthalmologist, for confirmatory testing. These eye specialists can perform a test called an electroretinogram (ERG).
ERG testing uses small probes on the skin to measure electrical signals from the retina. To perform the test, the dog sits in a dark room for a period of time. Then the vet shines a bright light into the eyes and looks at the electrical activity of the retina.
If it is a flat line (i.e. no activity), the diagnosis is SARDS. But if the ERG is normal, the dog may have optic neuritis, another condition that can cause sudden blindness.
Testing for Cushing’s disease
Most dogs with SARDS don’t actually have Cushing’s disease, just symptoms that look like Cushing’s. But sometimes the vet will still suggest testing the dog for Cushing’s disease. This usually involves either a low-dose dexamethasone test or an ACTH stimulation test.
What is the treatment for SARDS in dogs?
If your dog does get diagnosed with SARDS, treatment is primarily focused on helping your dog adjust to being blind. Unfortunately, as of now there is no way to reverse the effects of SARDS or even slow down its progression. Some veterinarians have tried using immunosuppressants like mycophenolate or prednisone for dogs. But these treatments didn’t prove to be effective in clinical trials.
Despite the lack of a treatment, the good news for these pups is that other clinical signs associated with SARDS tend to resolve spontaneously after several months. So, the main thing you need to do is help your newly blind dog adapt.
The following tips for living with a blind dog can be helpful:
- Avoid rearranging furniture. Dogs have a “map” of their home layout in their minds, so moving the furniture may cause your dog to bump into more things.
- Stick to your dog’s daily routine as much as possible so he or she knows what to expect.
- Use baby gates to block off access to dangerous areas (e.g. flights of stairs).
- Keep your dog in a fenced-in yard or on a leash so he or she can’t wander into danger.
- Fill in holes or pick up sharp sticks (or other dangerous things) in the yard.
- Keep dogs away from bodies of water (e.g. swimming pools, ponds, and streams).
- Use a harness with a “halo” in front to help prevent your dog from running into objects.
- Apply Dr. Buzby’s ToeGrips® dog nail grips to give your dog better traction and tactile sensation, which can increase his or her confidence when walking.
Are there natural treatments for SARDS?
Even though there are online sources claiming that specific foods and supplements will prevent or treat SARDS, there are no proven natural treatments.
Since dogs with SARDS tend to be overweight, it can be a good idea to help your dog lose weight for his or her overall health. However, putting your dog on a diet isn’t going to specifically treat his or her SARDS.
What is the prognosis for dogs with SARDS?
The good news is that despite sudden and irreversible vision loss, dogs with SARDS tend to have a good prognosis and an excellent quality of life. Barring any other illnesses, dogs with SARDS are likely to have a normal life expectancy.
You don’t have to take my word for it, though. A 2013 study in the Journal of the American Veterinary Medical Association looked at the outcomes for 100 dogs with SARDS. The survey that was part of the study indicated that 37% of dog parents felt they had an improved relationship with their dog after the SARDS diagnosis. And 95% of dog parents said they would discourage euthanasia after a SARDS diagnosis.
Thankfully, compared to more common eye issues like nuclear sclerosis in dogs or cataracts in dogs, SARDS in dogs is somewhat rare. In one study of all dog patients seen by the veterinary ophthalmology department at the UC Davis Veterinary Medical Teaching Hospital from 1991 to 2014, only 1.3% of them (151 dogs) presented with SARDS.
Don’t lose hope
I know that having your beloved dog suddenly become blind can be quite distressing for you and your dog. But I want to reiterate again that blind dogs can still have a wonderful quality of life long-term. It may take some time and effort from both of you, but your dog can learn to confidently navigate his or her world again.
So if your dog is diagnosed with SARDS, don’t lose hope! Work with your veterinarian and read books and blogs about living with a blind dog. And pay close attention to your dog’s behavior and reactions as you figure out how best to help him or her. It may take weeks or months. But in many cases, your dog can adjust well to being blind and continue to have a wonderful life.
Such was the case with Madeline, the Dachshund you met in the introduction. A visit to the veterinary ophthalmologist confirmed my suspicions that Madeline had SARDS, but it didn’t slow her down for long. Within a few weeks, she was navigating her house like a pro and confidently heading out for walks with her mom. And her other symptoms went away fairly quickly too.
Has your dog been diagnosed with SARDS?
Please share his or her story or any words of encouragement for other dog parents in a similar situation.