Blindness or sudden vision loss is a very scary time for those who love their pets. Sudden blindness in dogs can be caused by many factors and left untreated, may lead to permanent vision loss. To keep your pup safe and healthy, you must understand the reasons behind this condition. This article will discuss four common causes of sudden blindness in dogs: Sudden Acquired Retinal Degeneration (SARDS), retinal detachment, cataracts, and glaucoma.

1. Sudden Acquired Retinal Degeneration (SARDs)

Sudden acquired retinal degeneration (SARDS) is a sudden and irreversible loss of vision. SARDs do not cause pain or discomfort to your pet but will affect their ability to see. SARDs typically occur in dogs over the age of seven and any breed can be at risk for SARDs. The vast majority of dogs affected are small-breed dogs. Vision loss can develop over a period of days to weeks in both bright and dark light. This condition does not occur in cats.

The typical clinical symptom is rapid vision loss that has occurred over several days to weeks. Disorientation, knocking into things, and fear are all possible behavioral symptoms of sudden sight loss. Potential other concurrent clinical signs include lethargy, increased appetite, weight gain, and increased thirst and urination. Interestingly, these symptoms are very similar to those of Cushing's disease. Researchers are still trying to understand the potential link between Cushing's disease and sudden acquired retinal degeneration.

Unfortunately, there is no treatment available for SARDs in dogs. Multiple drug trials have been investigated but no clinically proven treatment exists for SARDs. Despite blindness, the prognosis is usually very good and system signs improve over a period of a few months.

2. Retinal Detachment

Retinal detachment refers to the separation of the retina from the back of the eye. Retinal detachment causes vision loss, which can be complete or only partial. Depending on the underlying cause and extent of retinal detachment, clinical signs of retinal detachment can vary. While there are many potential causes of retinal detachment in pets, the following is a list of common causes of retinal detachment in dogs:

  • High blood pressure (systemic hypertension)
  • Immune-mediated disorders
  • Infectious diseases (fungal, viral, etc.)

It is critical to seek expert treatment as soon after the injury as possible. To assist in diagnosis and treatment, if feasible, try to expedite a referral to an ophthalmologist. The treatment for each retinal detachment is determined entirely by the underlying reason.

3. Cataracts

A cataract is an opacification of the crystalline lens within the eye. Most causes of cataracts in young, middle-aged purebred dogs are inherited as there is a genetic mutation present. The second leading cause of cataract formation in dogs is due to diabetes mellitus. This is a common adverse effect of diabetes in dogs and does not affect cats the same way. Vision starts to become impaired as the cataract first develops and the eye may be functionally blind as the cataract advances. Surgical removal of the cataract and instilling an artificial lens is the most recommended treatment, regardless of cause. The surgery has a very high success rate, up to 95%. This procedure should be performed by a board-certified veterinary ophthalmologist.

4. Glaucoma

Glaucoma is an eye disease that leads to damage of the optic nerve. This results in vision loss and gradual onset blindness over days or weeks. Glaucoma can be caused by multiple factors including hereditary predisposition, age-related changes within the eye, injury to the eye (traumatic glaucoma), high eye pressure, and other diseases. Glaucoma is a very serious disease that requires immediate attention from your veterinarian as the treatment varies depending on the cause(s). Surgical intervention may be required to treat glaucoma if medications are not effective in reducing eye pressure or controlling secondary effects of the disease process.

As glaucoma is a painful ocular condition, dogs will often show signs of pain and discomfort such as reduced appetite, squinting, lethargy, and ocular redness. If blindness occurs, you may also notice a dilated pupil that is not responsive to light. If there is blindness and your dog has been diagnosed with acute glaucoma, there is the potential for the return of vision over a few weeks. Dogs with blindness and glaucoma for an extended period of time often have vision that is irreversible.

Sudden blindness in dogs can be caused by a variety of reasons, such as Sudden Acquired Retinal Degeneration (SARDS), retinal detachment, cataracts, and glaucoma. If your dog experiences sudden blindness, it is important to seek veterinary help as soon as possible so that the underlying cause can be determined and treated. Depending on the cause of blindness, there may be a chance for vision improvement with treatment.