Sudden Acquired Retinal Degeneration Syndrome (SARDS)
What is SARDS?
Sudden Acquired Retinal Degeneration Syndrome (SARDS) is a retinal disease causing blindness over a period of days to weeks. The onset of blindness can be very sudden and occur virtually overnight.
The blindness results from a degeneration of the visual cells in the retina (rods and cone or photoreceptors).
What are the signs of SARDS?
The eyes may appear normal but the animal is blind. The pupils may have abnormal responses to light. Animals may have only blindness or other additional signs like increased drinking, urination and appetite.
What causes SARDS?
The exact cause of SARDS is unknown. Theories for the cause of the disease include toxins and autoimmune disorders but none of these have been proven*.
How is SARDS diagnosed?
SARDS animals may have a normal eye exam or show subtle signs of the disease. The diagnosis is made from an electroretinogram (ERG) that evaluates retinal function.
Brain diseases and optic nerve diseases can appear just like SARDS by causing blindness over days to weeks, and an ERG can distinguish between these neurological diseases and SARDS. Knowing the cause of blindness is important for the long term expectations, treatment options and prognosis for life.
With SARDS, the ERG will register no function and be flat. With optic nerve or brain disease, the ERG will be normal.
How is SARDS treated?
SARDS does not have any known effective treatments* but animals are generally healthy except for their eyes. The other signs of increased drinking and urination usually improve with time. A small percentage of the dogs with SARD also have another hormonal disease (hyperadrenocorticism) that may require additional tests and medical treatment. If not SARDS, some retinal diseases that are caused by infection, inflammation, cancer or autoimmune disease can be treated.
Dogs that are blind can still have a wonderful quality of life!
SARDS takes vision away so quickly that dogs will have an adjustment period. In the beginning, dogs will bump objects, act confused and be more clingy. In the long run, most dogs adjust well to their loss of vision. Dogs have many other senses like their hearing and smell that far exceed our own and adapt very well over time to their vision loss.
More reference information:
* An excellent think tank article for more technical information on SARDS:
“Sudden acquired retinal degeneration syndrome (SARDS) - a review and proposed strategies toward a better understanding of pathogenesis, early diagnosis, and therapy”
by András M Komáromy 1 2, Kenneth L Abrams 3, John R Heckenlively 4, Steven K Lundy 5, David J Maggs 6, Caroline M Leeth 7, Puliyur S MohanKumar 8, Simon M Petersen-Jones 1, David V Serreze 9, Alexandra van der Woerdt 10,
Vet Ophthalmol. 2016 Jul;19(4):319-31. doi: 10.1111/vop.12291. Epub 2015 Jun 20.