How does SARDS cause blindness in dogs?

Sudden Acquired Retinal Degeneration Syndrome, or SARDS, is a rare disease in dogs and is one of the ailments of what causes blindness in dogs. The current cause of SARDS is still unsure. Medical understanding of the cause of SARDS is poor with only a few theories.  Suggested causes are elevations in adrenal sex hormones, toxins, autoimmune issues, or Cushing’s Disease. At present, about 4,000 cases are reported annually with female dogs being more numerous than males, & any breed or mixed breed can succumb. Young dogs are less likely to develop SARDS than middle-aged or older dogs.

Polyuria and polydipsia (excessive urination & thirst), polyphagia (excessive hunger), weight gain, and lethargy are symptoms that occur approximately two weeks prior to the onset of blindness. Vision loss in SARDS is rapid and complete blindness tends to occur anywhere from 24 hours to 4 weeks after being affected.

Dogs with SARDS will develop generalized tapetal hyperreflectivity, which is when less light is absorbed by an atrophic, or wasting retina. Additionally, they will have attenuated (unnaturally thin) or diminished retinal vessels. Rod and cone cells will be lost and other layers of the retina will begin to degrade. The clinical appearance of the eyes will be indistinguishable from those of dogs with chronic retinal degeneration, due to other causes such as PRA or vitamin A deficiency. Testing can rule these two causes out.

Distinguishing SARDS From Other Causes

SARDS needs to be distinguished from other causes of sudden blindness that have no visible pathology but do have life-threatening complications. Some of the other causes that need to be ruled out are:

  • Demyelinating inflammation of the optic nerve – optic papillitis (when the head of the optic nerve is involved).
  • Retrobulbar neuritis (when the posterior of the nerve is involved) due to diabetes mellitus, low phosphorus levels, or hyperkalemia.
  • Tumors of the optic nerve or brain and other central nervous system disorders

An Electroretinogram (ERG) is often performed to diagnose SARDS and it tests what function remains in the retina. An ERG is not harmful or painful but the dog needs to be still so in most cases, a general anesthetic is required to undergo this type of testing.
After results confirm a SARDS diagnosis in a dog, its owner needs to decide where to go from there. No treatment with definitive positive results is currently available.

Dr. Alfred J. Plechner, DVM, in Los Angeles believes he has a treatment course for SARDS.  It is up to the owner and their veterinarian if they wish to explore any of his protocols. No controlled studies have been conducted on these treatments, nor any studies are done to evaluate the safety, so one needs to consider these possible options carefully. 

The use of intravenous immunoglobulin has been investigated due to similarities between SARDS and human immune-mediated retinopathy, by Dr. Sinisa Grozdanic, DVM, PhD of Eastern Iowa Veterinary Specialty Center.  Presently, only two dogs have regained some sight, and prognosis to retaining that sight is unknown. Dogs with severe cardiac or kidney disease are not candidates for sards treatment.  It also does not work in a dog whose retina degeneration is too advanced.

Signs of SARDS in Dogs

The most important thing to remember is SARDS is not a death sentence and blind dogs can enjoy happy, healthy, long lives. Getting a  SARDS diagnosis for your dog is devastating and can initially be a struggle for you both. You can get through this for your dog. Don’t give up and don’t give in to the heartache caused by the initial diagnosis.

Moving forward, there are many things you can do to improve your dog’s quality of life. As a blind dog, make things easier for you both. First, allow for an adjustment period. Understand that things will change and it might not be easy at first. Together you and your dog can overcome these obstacles.

Various reports say that many dogs with SARDS retain permanent changes such as blindness, increased hunger, thirst, frequent urination, and weight gain.  

Increased hunger

Think of your dog as a puppy again. Pick up anything they may be tempted to get into. Their greater appetite may drive them to seek out new sources of food. This doesn’t have to be a downside.  It can be an opportunity to use this drive for food to teach your dog new things, such as routes throughout the house. You can purchase puzzle toys designed for scent work, that can be fun games for both of you.

Increased thirst

Talk to your veterinarian about how much water you should provide your dog with SARDS.  Try a water fountain type drinker that has a larger reservoir, so you don’t need to fill the bowl as often due to increased urination.

This may seem like a big deal at first, but if you have a doggie door, your dog should be able to learn the route to and from the door just fine.  You can also use textured rugs in the interior and exterior, so your dog knows where the door is from the feel of the rug.

Learn their new potty schedule and set timers to remind yourself. There are washable and disposable canine diapers designed for both male and female dogs.  This is helpful to get through the initial adjustment phase, with less mess and clean up. Stock up on enzymatic cleansers and remember that because they are drinking and urinating more, their urine will be more diluted  – so it will be easier to clean up.

How to Take Care of a Blind and Deaf Dog at Home

Your dog most likely has a good mental map of your home already, so don’t move furniture around or make any sudden changes that can confuse them.

How to help a blind dog with stairs? if you have stairs, block them off, and use a different texture of rug to indicate the top and bottoms of the stairs. You can use this method of tactile sensations to mark important areas for your dog. You can also use auditory and scenting methods in a similar way. Your dog will likely rely on you more initially, then become a more independent. Your dog will most likely develop a stronger bond with you. They have one less sense they will seek out . Blind dogs appreciate your company & the security it provides even more. When you go on walks, take more time to allow your dog to smell things.  They can still enjoy walks, just in a different way.

Muffin’s Halo Harness For Blind Dogs

Helping your dog navigate without bumps or accidents will be your goal. You can get a Muffin’s Halo for Blind Dogs.  It is an amazing pet product that allows your dog to use their tactile senses. It is designed to guide them while still protecting them from injury. Muffin’s Halo is especially useful when moving to a new home or in new places. The blind dog halo is a dog product that provides protection from crashing into objects and possibly injuring their eyes. 

View the Muffin’s Halo For Blind Dogs Catalog.

In closing, remember that the diagnosis of SARDS may at first be emotionally painful and even frightening. The good news is there are many tools & resources available to help make your blind dog’s live easier and safer – such as the Muffin’s Halo for Blind Dogs.

Written by D.H. Styx / Parker / Duelism for Muffin’s Halo for Blind Dogs 02.2017

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC339566?

Sudden Acquired Retinal Degeneration Syndrome

http://avmajournals.avma.org/doi/abs/10.2460/javma.243.10.1426

http://dr.plechner.com/sards-corner/

http://www.pethealthnetwork.com/dog-health/dog-diseases-conditions-a-z/sudden-acquired-retinal-degeneration-syndrome-sards-dogs

https://www.sciencedailey.com/releases/2007/05/070531094241.htm