SARDS, or Sudden Blindness in Older Dogs
Sudden blindness in older dogs, known as sudden acquired retinal degeneration syndrome (SARDS), is a disease that leads to sudden and irreversible blindness in dogs. This medical condition affects dog’s retina, which is the structure present at the back of eye that functions like the film of camera. Without proper functioning of retina, the affected animal can’t see. In the early stage of this medical condition, the retina appears normal even though it is not working. In addition to sudden loss of vision, many pet owners also notice enlarged and dilated pupils.
Often, this syndrome occurs in the adult dogs of various ages ranging from 6 to 14 years old. The affected dogs remain in good health, but some dogs may have a recent history of lethargy, obesity, increased appetite, increased consumption of water or/and increased urination.
Dogs with SARDS may develop
- Permanent blindness over a rapid course (typically days to weeks)
- Difficulty navigating at night
- Failure to track treats
During the weeks and months preceding the blindness of dogs, they also experience marked increases in their appetite and/or thirst with the subsequent weight gain and changes in their urinary behavior. The affected dogs may also suffer from bladder infection.
Cause of SARDS
The underlying cause for sudden acquired retinal degeneration syndrome is currently not completely understood, however, recent investigations suggest that it is an autoimmune disease. It means that dog’s immune system, which fights off body infections, instead attacks the own tissue of body by developing the so called “auto-antibodies”. Some predisposed breeds include and include Miniature Schnauzers and Dachshunds. This medical condition seems to be more frequent in the middle aged to elderly dogs, especially female dogs.
Diagnosis of SARDS
For animals with acute vision loss, an electroretinogram (ERG) is recommended in order to assess retinal function and definitively diagnose the process of disease. With the help of this test, it easy to differentiate SARDS from other causes of acute blindness such as optic neuritis, which may require further treatment and work up.
The process of electroretinogram involves simply putting a specialized contact lens on the eyes of a lightly sedated or awake dog. The veterinary doctor flash a series of lights in the eye of dog and the electronic signals from the retina are recorded. In the SARDS patient, normal electronic responses of retina are extinguished. In the beginning, early changes from electroretinogram are microscopic; therefore, ophthalmic examination may reveal normal retinas.
Treatment of SARDS
Till date, there is no successful and effective treatment available for the sudden acquired retinal degeneration syndrome. There are various research work is going on to find the treatment of this medical condition. A clinical research group treated some dogs suffering from SARDS with a human drug called ‘IVIG’. In this research, some dogs regained the guidance vision but full recovery was not achieved in any of the cases. However, this treatment may lead to the sudden death of dog due to allergic reactions, therefore, it is not recommended.
Things to know about SARDS
The affected dog adjusts well to being blind and is able to resume his normal quality of life. All the affected pets should also be monitored long-term for the secondary cataract formation that may require prophylactic medical therapy to control the inflammation that could cause discomfort. It is advised to the pet owners to take the safety precautions, particularly around stairs, pools, roads, etc. There are training techniques for dogs with blind dogs, as sudden acquired retinal degeneration syndrome (SARDS) is not a painful condition. (Book recommendation: Living with Blind Dogs)
This is a post by Tamanna, an animal lover who has owned a number of pets. She loves writing about animal companions and has written numerous articles focusing on dog breeds, pet training, pet grooming and pet nutrition and health.