Blind Dogs: What Must I Pay Attention To?

 If your dog is blind, it will be more dependent than usual on your support and care. The following article will outline how your dog could go blind and what you have to pay attention to with a blind dog. 

Tips: How to master everyday life with a blind dog

Blind dogs are severely limited in their ability to see, therefore need your help in everyday life. The following seven tips will outline how you can help your pet through the day and improve it’s quality of life despite its blindness. 

Symptoms: What are the signs of blindness in dogs?

The symptoms depend on how severely limited your dog’s ability to see is. If it can no longer see in both eyes, the clinical diagnosis is more straightforward than if it has only lost its sight in one eye. 

Depending on how severely your dog’s visual acuity is limited, you can observe the following symptoms: 

• Reluctance to exercise 
• Disorientation: Your dog stumbles over objects or runs into walls. 
• Nervousness 
• Changed behaviour: It seeks proximity to you more frequently or reacts aggressively. 
• The lenses may be cloudy on one or both sides. 
• The pupils are dilated. 
• Depending on the cause, the affected eye may be swollen or shrunken. 
• Your dog may suffer from clear to purulent eye discharge (epiphora). 

Diagnosis: How do I recognise a blind dog? 

If you wish to know whether your dog is going blind, you can get it examined by your vet. They will carry out the following tests, amongst others, as part of a special eye examination, which you can also perform at home yourself beforehand. 

1. Examining reflexes 

The vet can examine the ocular function of individual eyes by triggering the threat reflex (shutting the eyelids when an object approaches) and glare reflex (the pupils dilating when light enters). If your dog shows no reflexes, this is a sign that its eye is limited in these functions. 

2. Cotton wool test 

With this test, the vet will drop an odourless cotton wool ball in front of your dog at an eye distance of around 30cm. It will make no sound. If your dog’s eyes don’t follow the cotton wool, this indicates that its ability to see is diminished. Caution is advised though, as this test only works when your dog is attentive. 

3. Obstacle course 

For this test, the vet needs an odourless object to place in the room. You now have to lead your dog in the direction of this object. If it misses the object and stumbles, the vet will assume that your dog is visually impaired. 

The vet will carry out further tests if they suspect that your dog is blind. For instance, they will check your dog’s tear production using a paper strip or observe the front eye in the dark with a slit lamp microscope. 

The vet needs an ophthalmoscope to be able to assess the rear section of the eye too. They will then rule out injuries by staining the eye with a certain colouring (fluorescein). They use a tonometer to examine the inner eye pressure and rule out glaucoma. 

Treatment: How can a blind dog be treated? 

The treatment of blind dogs is always based on the underlying cause. 

If your dog’s retina is intact, eye specialists can usually operate on cataracts. 

In contrast, glaucoma can only be treated to a certain extent with eye drops and infusion therapy. If your dog is still suffering from severe pain, your vet may recommend an operation or removal of the eye. 

There is no general treatment for detachment of the retina. It is based on the underlying disease and the extent of the detachment.

Causes: What are the reasons for a blind dog? 

The eye is a complex sensory organ. It consists of several tissues and is essential for your dog’s vision. As well as external influences (e.g. injuries, chemical irritants), other underlying diseases can also damage the eye and lead to your dog going partially or fully blind: 

Blindness in old age 

It’s normal for eyesight to diminish in old age. This is because the core of the lens gradually becomes cloudy. 

Cataracts

Some diseases cause the lens to cloud and sunlight to no longer reach the back of the eye. Cataracts can be innate or hereditary for dogs. 

The latter can occur if your dog suffers an eye injury or from a metabolic disorder. If your dog has diabetes, the sugar concentration in the blood is increased. The sugar is then deposited inside the lens. 

Glaucoma 

The eye naturally forms aqueous fluid that moistens the surface. If it produces too much aqueous fluid or this can no longer flow, the inner eye pressure will increase. This gradually harms the eye and leads to irreversible and painful damage. As a consequence, the dog will go blind. 

Depending on the cause, specialists class glaucoma as primary or secondary: 

Primary

Hereditary malformations of the chamber angles lead to them being too narrow and interfering with discharge. The following dog breeds suffer from primary glaucoma particularly frequently: 

• American Cocker Spaniel
• Border Collie
• English Springer Spaniel
• Shar Pei
• Flat coated Retriever

Nevertheless, it can affect other dogs too if a spontaneous genetic mutation occurs during the embryonic phase. 

Secondary

If aqueous fluid cannot flow because of an acquired obstruction, vets refer to this as secondary glaucoma. It may be that the eye is so severely swollen due to an infection that discharge is disturbed. 

Retina detachment 

If the inner retinal sheet detaches from the outer sheet of the pigment epithelium (retina), the retina’s sensory cells required for vision die. Inflammatory fluids or high blood pressure are common causes of the two layers separating. 

Eye tumours or bleeding due to injuries can also lead to the retina detaching and the dog going blind.