Sudden acquired retinal degeneration syndrome (SARDS) is a retinal disease of unknown cause which results in an acute onset of permanent blindness in older dogs. Affected dogs- usually middle-aged or older- and all breeds are affected with SARDS. There is no evidence to indicate that this syndrome is inherited and that there is no proven way of preventing it. The major symptom is often acute loss of vision. Many dogs usually go totally blind within four weeks of visible vision loss and others usually have total vision loss within one to two weeks.
Signs and Symptoms of SARDS:
Although sudden blindness is the most obvious sign of the disease, dogs can also experience the following:
- Infrequent blinking or slight redness of the eye
- Dilated pupils with little or no response to light
- Increased appetite
- Increased thirst and urination
- Sudden weight gain
Such signs and behavioral changes can be indicators of SARDS and other conditions. It is important that you pay attention to any improvement in your dog’s actions or vision. Pets with one or more of these symptoms should be assessed immediately by a veterinarian. Your Vet will work to develop a proper treatment plan and diagnosis. Pets with vision loss may even be referred to a veterinary ophthalmologist or other specialist for further treatment and testing.
How is SARDS Diagnosed?
An electroretinogram (ERG) must be done to diagnose the disease. This is an electrical test of the function of the retina. The test is not unlike an electrocardiogram (ECG) performed on animals and humans to check the function of the heart. The test requires special equipment designed to detect tiny electrical impulses that occur in the retina. During the test, the retina is stimulated by light and the retinal reaction is recorded by the electrodes. If the retina works, a positive waveform can be produced on the screen of the ERG computer. Dogs typically require sedation or general anesthetic for this examination, because it can only be done if the dog does not move. However, the test can be done without sedation in very comfortable dogs. The examination is not painful and does not affect the eye or the patient.
How is SARDs treated?
If not SARDS, certain retinal disorders caused by infection, inflammation, cancer or autoimmune disorder is easily handled. SARDS do not have any known successful remedies, but animals are usually safe except for the eyes. Many symptoms of increased drinking and urination typically develop over time. A small number of dogs with SARDS may have another hormonal disorder (hyperadrenocorticism) that may need further testing and medical care.