What Causes Blindness in Dogs?

what causes blindness in dogs

Has your dog started bumping into things?  Does it seem like he is more afraid of noises than usual? Or does it seem that he is not aware of his surroundings or his boundaries?  If so, then your dog may be experiencing the beginning stages of vision loss.

There are many different reasons your dog may begin to experience some vision loss or even total blindness. Ranging from normal aging to heredity to disease or injury, the circumstances of each dog’s blindness dictate the cause. If you believe your dog is facing some level of vision loss, be mindful of his whereabouts as many situations may suddenly become dangerous for your pet. For example, a dog who is used to roaming the yard outside may no longer be aware of his surroundings and walk in front of a car. Once you are sure you have your pet in a safe place, call your veterinarian. Because there are so many reasons for blindness in dogs, and you may not be able to tell what is happening, it is a good idea to visit your veterinarian at least once a year so he can evaluate your pet’s vision regularly.

Symptoms of Blindness in Dogs

You may not realize at first that your companion is losing or has lost vision, especially if it occurs gradually. Blindness may present as a symptom of a disorder or be the result of an injury, therefore it is important to recognize the symptoms. Some signs your dog is having vision trouble may include:

what causes blindness in dogs

  • Bumping into things or general clumsiness
  • Acting afraid or reluctance to move
  • Jumpiness
  • Apprehensive during play
  • Unable to find water, food, and toys
  • Confusion
  • Not wanting to go outside
  • Depression
  • Sleeping more than usual
  • Anxiousness
  • Excessive thirst
  • Eye redness
  • Enlarged pupils
  • Cloudiness of the eyes

In identifying blindness, it is important to understand that dogs can experience varying degrees of vision loss. Your dog may be:

  • Partially Blind  This includes blindness in one eye or cloudy vision during which your dog can still see shapes and light.
  • Intermittently Blind  In this case, vision loss comes and goes randomly.
  • Completely Blind  If your dog is completely blind there is total vision loss and he will be unable to see anything, including light.

Causes of Blindness in Dogs

 

As previously mentioned, there are a number of reasons your dog may develop vision loss, either gradually or suddenly. Some of the most common causes include:

 

  • Old age
  • Infection
  • Injury or trauma to the eyes
  • Glaucoma – Increased pressure of the fluid in the eye which damages the optic nerve and retina while causing severe pain.
  • Cataracts – A painless cloudiness of the eye lens resulting in partial or complete blindness
  • Diabetes – High blood glucose, one in ten dogs are diabetic and 75% of those will end up blind.
  • Progressive Retinal Atrophy (PRA) – An inherited disorder which causes retinal deterioration.
  • Suddenly Acquired Retinal Degeneration Syndrome (SARDS) – A painless, but sudden loss of vision which is impossible to cure and, currently, has no known causes.

Certain breeds are also more prone to vision loss, such as Spaniels, Siberian Huskies, Malamutes, Shar-Peis, Poodles, Great Danes, Dachshunds, Dalmatians, Chow Chows, Basset Hounds, Beagles, German Shepherds, Chihuahuas, and Shih Tzus.

Diagnosis & Treatment

what causes blindness in dogs

Your veterinarian will need to do a complete physical on your dog to determine the cause of blindness, including an eye examination, pupil reaction time, reflexes, body temperature, blood pressure, weight, breath sounds, pulse oximetry (oxygen level), respirations, and heart rate. It is important for you to share a complete history of your dog’s symptoms that you may have noticed, such as abnormal behavior or eating patterns. Bring your pet’s medical and vaccination records if possible.

Diagnostic tests will need to be done to rule out underlying diseases such as diabetes and Cushing’s disease. Some of these tests may include blood glucose, serum chemistry analysis, complete blood count, comprehensive metabolic panel (CMP), urinalysis, blood urea nitrogen (BUN), serum cholesterol, bilirubin, and tonometry. Other procedures usually done at this time are serum alkaline phosphatase (ALP), serum alanine aminotransferase (ALT), electroretinography (ERG), ACTH stimulation test, and ocular ultrasound. You may need to take your dog to a veterinary ophthalmologist for further testing if your primary vet is unable to determine a diagnosis.

The treatment for your dog’s blindness greatly depends on the cause. In most cases, such as with SARDS and PRA, there is no treatment. However, if there is an underlying disease, treatment of that condition may alleviate the blindness. Otherwise, the only treatment is to train your pet to live with blindness. Your veterinarian may be able to recommend resources to help prepare you and your dog for life with blindness.

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