Day Blindness in Dogs

The cones in your dog’s eyes can degenerate as a result of a mutant gene known as CNGB3. This condition is also known as hemeralopia. It is usually around your puppy’s seven-week age that the first signs of this condition will appear.

The bright light of day renders your pet almost blind, and they are fearful to venture into brightly lit areas. This condition was first detected in the mid 1960’s. Research with test breeding found that both parents must carry the gene (autosomal recessive disease) to affect the offspring.

Day blindness comes from deteriorating ‘cones’ in the retina of your dog’s eyes. The cones enable your pet to see in the bright daylight.

• Your dog may seem disorientated when it out in the full sunlight but be fine at night 
• Your pet may not be able to find a toy or ball without using its nose to find it 
• Bumping into things during daylight 
• Doesn’t respond to your visual gestures 
• Prefers the shaded areas in the yard 
• Reluctance to go up steps 
• Tripping and stumbling 
• At night, all the symptoms seem to go away, your dog can chase and find the ball, bound up steps, and the clumsiness disappears 

Types  

Day Blindness in dogs (Cone Degeneration Disease) is one type of blindness that may affect your dog. Cone shaped cells in the retina are responsible for sight in bright daylight. Degeneration of these cones affects the day sight.  Exposure of your young pup to daylight causes irritation or pain. At night, they recover their eyesight and can move freely. 

Progressive Retinal Atrophy (PRA) is more common in dogs and affects the retina causing loss of sight. The rod shape cone cells in your dog’s eyes are not affected with this condition, and all sight is lost.

• Day blindness is an inherited problem for many breeds of dogs including Malamutes, Labradors, and German Shepherds
• The cause of day blindness is the degenerative effect on the retinal cones which are cone shaped cells within the retina 
• Degeneration of the cone cells cause blindness during the day and discomfort and uncertainty for your dog during daylight hours 
• Usually noticeable in your dog from seven weeks onwards, which is when retinal development is fully completed 
• Breeding from parents that are both genetically affected can pass the condition onto the puppies
• The mutant gene is known as CNGB3

If you notice your young puppy is quite hesitant to go outside and is unsteady and bumping into things a normal dog would not, then it is time to take your young pup to your veterinarian, who may suggest a veterinary ophthalmologist check the condition of your dog's eyes. Your specialist will give your dog a full evaluation of health, and consider the past medical and travel history of your pet. Once a dog has this condition, there is no cure, but it can be managed. If your dog is a pet and not a working dog, he can live a comfortable life with just a few adjustments. 

Breeding dogs that have produced a day blind puppy should be removed from the breeding pool to prevent more pups with this sad condition. Both mother and father need to be removed as they are proven to be carriers of this condition. Day blindness is not life threatening if your dog is kept within a secure yard, and is walked on a lead to protect them from wandering into things and getting injured. At night, they are just as normal as any other young dog.

Your veterinarian may choose to refer you to an ophthalmologist who will examine the eye structure and perform an electroretinograph to confirm the condition.

Your veterinarian can suggest a few things to help you manage your dog, such as using verbal signals rather than visual hand signs. Getting your young dog used to his surroundings (night time is a good time to begin this familiarisation process) will help him to be more confident during the bright day. Walking your dog on a leash, especially a harness, will provide him with support and aid maneuvering around the area.

There are dog sunglasses that are for sale, and these may assist your dog during the day.Glasses such as “Doggles” may be an option. These glasses are more than just a fun accessory; the army has utilised the glasses for their field dogs to protect their eyes from dust or dryness when skydiving with their masters. The tinted glass may just help your dog enough for him to become more mobile during the day. Management and support are really all that you can do for your friend. Animals are amazingly versatile and can adjust to almost any condition without a murmur. Once you have done all you can, just enjoy your dog and show them how special they are.

As recovery from this condition is not an option although ongoing research is continuing, it means that support and management are the next two best things for you. Keeping your dog healthy through diet and regular exercise, and helping your dog to get familiar with his back yard will help him to become a regular dog. The use of canine sunglasses may be a help to your dog, just make sure they are fitted comfortably, or your dog’s mission will be to get them off and bury them as soon as you are not watching.

Canines who have day blindness should not be used in breeding as the condition will be passed onto their puppies. Remove all unnecessary objects in the area to make getting around during the day easy for your dog. Apart from that, enjoy the special friendship you have with your amazing dog.