Sudden acquired retinal degeneration syndrome

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Sudden acquired retinal degeneration syndrome (SARDS) remains poorly understood, but it causes rapid, permanent blindness due to retinal degeneration. Many patients have concurrent endocrine abnormalities, such as hyperadrenocorticism (Cushing’s), hypothyroidism, or other hormonal imbalances. Almost 50% of the patients diagnosed occur during the winter months (December and January). The average age of affected patients is 8.5-10 years, and most commonly female spayed dogs. SARDS patients often lose their vision very quickly (within hours to days), although some may take longer. Changes within the retina are usually seen on a scale of weeks to months, but changes have been noted to occur as soon as days after the onset of blindness. The most consistent finding is a completely extinguished electroretinogram (ERG) test, consistent with no electrical activity of the retina.

While no treatment has proven effective, SARDS has been anecdotally treated with systemic immunosuppressants, such as Prednisone or Leuflonamide. If immunosuppressive therapy is elected, patients are reevaluated in a few weeks to months. If any improvement is seen, discussion of long-term therapy can occur. If no improvement is seen, the patient is generally weaned off the medications.

In a recent study on the long-term outcome of SARDS patients, 80% of owners reported their dogs had a moderate to excellent quality of life. The most frustrating changes were blindness for 69%, polyuria (increased urination) for 8%, polyphagia (increased appetite) for 7%, and weight gain for 6% of owners. Polyphagia (increased appetite) seemed to be the only clinical sign that worsened or progressed with time.

Moderate to excellent navigation in the house was reported by 87% of owners, navigation in the yard by 81% of owners, and navigation in new surroundings by 41% of owners. Almost 40% of clients actually reported an improved relationship with their dog.

In addition to oral steroids, owners may consider the use of oral antioxidants. While this has not been scientifically proven to help with retinal degeneration, it is thought to help slow progression of secondary effects, such as cataracts. There is a veterinary supplement, Ocu-GLO™, that is formulated for small and large dogs. If administered, please follow the instructions on the bottle based on patient size.

To help your dog transition to complete blindness, you can:

  • Continue to offer full lighting in darker areas of the house and yard
  • Avoid walks at twilight
  • Move dangerous or unstable obstacles around the house to safer and more stable conditions
  • Provide non-slip flooring in slippery areas of the house
  • Use different textures or scents around the house to help navigate and adapt
  • Purchase a blind dog halo harness to help protect your dog’s face and help them navigate better
  • Purchase dog-specific sunglasses to protect the eyes from the sun and from bushes, etc. while outside

While we do not necessarily need to recheck the retinas, we recommend recheck every 1-2 years for patients, to ensure they are not developing additional conditions that could become painful, such as inflammation, cataracts, or glaucoma.