SARDS  (Sudden Acquired Retinal Degeneration Syndrome)

by Anne Jones RN, BSNE
& Mayno Blanding of the BFCA Health Committee

It was a shock to find the first reports of SARDS in Bichons a few years ago, as this seemed to be a new malady for the breed; however, Bichons are now officially listed as “particularly predisposed” to this disease. Unfortunately there is no treatment, the cause is unknown, and it’s unknown whether or not it is genetic.

SARDS stands for sudden acquired retinal degeneration syndrome. There is little if any advance warning that the dog is afflicted until the dog starts to run into objects, though in some instances the progression may begin a week or two before total blindness occurs. The pupils will appear normal but are not reactive to light and are dilated. The condition is a sudden death of the cells (rods and cones) that enable the eye to see. These same nerve cells are the ones affected by PRA (progressive retinal atrophy) but these appear to be distinct and different conditions.

In SARDS loss in vision spans from a few days to a few weeks and involves both day and night blindness. Early PRA primarily affects night vision first and advanced PRA causes blindness; however, PRA has gradual onset while SARDS is virtually instantaneous. There do not seem to be the same complications with SARDS as in PRA in that there is no uveitis (inflammation of the iris and ciliary body of the eye) or development of secondary cataracts.

Indications are that this is a disease of middle-aged and older dogs, and approximately 60% of affected dogs are females. It has been theorized that SARDS is an autoimmune disease (in particular Cushing’s Disease, because during the weeks and months preceding blindness most dogs affected with SARDS will experience an increase in appetite and/or thirst with subsequent weight gain and increase in urinary output); however dogs with this condition who have been treated with immunosuppressive therapy have not demonstrated any clear improvement in overall outcome compared to untreated dogs.

DIAGNOSIS of SARDS is made based on the patient’s history, the presence of partial to complete blindness in both eyes, normal appearing retinas, and characteristic changes on an electroretinogram (ERG), because changes in the eye are microscopic in nature. The ERG is a test used to evaluate photoreceptor function and can only be performed by a veterinary ophthalmologist.

There is no treatment for SARDS; however, it does not seem to be painful for the dog whose distress stems from the suddenness of the attack. The dog’s owner must adjust to a newly blind dog with increased thirst with the consequential elimination of fluids and a voracious appetite necessitating a strict diet to maintain normal weight.

In a study done in 2013 by researchers at the University of Missouri, owners of 100 dogs diagnosed with SARDS completed a questionnaire addressing, among other things, the quality of life for their dogs.  Dogs in which SARDS was diagnosed at a younger age were more likely to have alleged partial vision and higher owner-perceived quality of life.  Thirst increased over time for all dogs. Medical treatment, attempted in 22% of the affected dogs, did not help in any way.  Many respondents reported an improved relationship with their dog after diagnosis, and almost all indicated that they would discourage euthanasia of dogs with SARDS because their pets had good quality of life.

In response to several questions in regard to SARDS, we received the following response from Dr. Kirk Gelatt: “SARD occurs primarily in middle aged female dogs. Bichon PRA is not as common as cataract; probably by a factor of 1 PRA to 100 cataracts or more. SARD has been associated with liver, pancreas, and adrenal gland abnormalities. However, still no single association and often SARD dogs have normal blood chemistries. End-stage SARD is difficult if not impossible to distinguish from advanced PRA.” While Dr. Gelatt’s answers provide more questions to be asked, they do show that this condition is not yet fully understood by veterinary ophthalmologists. Is there a relationship to PRA? Is this a disease that will continue to increase among Bichons?

Please report any Bichon diagnosed with SARDS to the Health Committee to enable us to track it in our breed. We already know that there are many Bichons with Cushing’s Disease, so it is possible that the numbers of SARDS affected Bichons may increase if there is indeed a relationship.

 

References:

“Sudden Acquired Retinal Degeneration Syndrome (SARDS) in Dogs”, by Dr. Nancy Kay, DVM, DACVIM, Posted September 25, 2014 in Dog Diseases & Conditions A-Z

“Long-term outcome of sudden acquired retinal degeneration syndrome in dogs”,  Journal of the American Veterinary Medical Association

November 15, 2013, Vol. 243, No. 10, Pages 1425-1431

doi: 10.2460/javma.243.10.1426

Information for this article also comes from www.sardsawareness.org, an article in YOUR DOG, April 2004, Volume X, Number 4 and various other texts.

Additional information has been provided by Dr. Kirk Gelatt, University of Florida, who is quite familiar with eye diseases in Bichons. Our thanks to Dr. Gelatt for his continued interest in our breed.