Sudden Blindness in Dogs

Physical trauma can manifest in various ways, such as a traffic collision, serious fall or even foreign objects entering the eye. These injuries have the potential to damage the tissues of the eye and result in sudden loss of vision in the dog. This could be due to issues such as a detached retina as a result of a physical blow. Such a blow would need to be very serious and is likely to cause other injuries.

Other ways in which physical trauma can cause sudden blindness in dogs include increased intracranial pressure, intraocular hemorrhage or eye muscle damage. It will usually not be until the dog has been assessed by a veterinary professional that the level of vision can be accurately determined.

Read our related article to determine how to know if a dog is blind.

Treatment of trauma in dogs

Traumatic injuries can cause different levels of ocular damage, the extent of which can determine whether vision can be restored. In cases such as retinal detachment, the outcome of surgical intervention is often positive^[1]. Other damage as a result of traumatic injury may not be reversible.

If a dog has sustained significant trauma, you should take them to a veterinarian immediately. Even if they appear to be fine, there could be internal damage which does not produce symptoms until later. Prognosis can be improved if the treatment is swift.

Another symptom of physical trauma is blood in the dog's eye, something which can cause temporary or permanent vision loss.

Surgery may be a way to treat sudden blindness in dogs, but it may also be an indirect cause. Even relatively minor surgical interventions require a dog to undergo general anesthetic. The effects of general anesthesia may result post-surgical complications derived from the anesthetic process. One of these complications is blindness, which can occur if the dog has suffered hypotension, hypoxia (lack of oxygen), hypothermia or has spent too long a period under anesthetic.

The surgery itself may also cause blindness. Whether due to malpractice or as a complication from surgical intervention, damage can occur to the eye tissue. This is uncommon and very unlikely to affect both eyes.

Treatment of anesthesia complications in dogs

In these cases, the dog wakes up completely blind and may show signs of dysphoria, delirium, restlessness or nervousness. This is due to disorientation and being suddenly unable to see what is happening. Fortunately, this blindness usually resolves itself in the vast majority of cases after a few days of rest. It does not require specific treatment beyond that indicated for the surgery to which they have been subjected.

As with all their senses, a dog's vision is controlled by the brain. This organ is responsible for receiving all the information registered by the eyes, interpreting it and transforming it into images. Any pathology or injury to the central nervous system may affect the senses, one of the most common cause of sudden blindness in dogs.

Of these neurological disorders, inflammation of the optic nerve is one of the most common to result in blindness. Known as optic neuritis, it is often the result of infection, although it can be due to autoimmune disorders and encephalitis, among other causes. Certain microorganisms are capable of invading the dog's nervous system and attacking said nerve, preventing the animal from seeing, even if its eyes are not anatomically affected.

The following are other potential causes of sudden blindness in dogs related to neurological issues:

• Inflammation at the brain level
• Increased intracranial pressure
• Brain tumors
• Cerebral edema or hemorrhage

Treatment of neurological disorders in dogs

Blindness caused by a neurological disease will need to be assessed by a veterinary professional. They will evaluate the extent of the neurological damage, as well as best determine the underlying cause on which the treatment will be based. This will require a complete neurological examination as well as diagnostic imaging tests such as an MRI.

Neurological alterations which cause blindness are often temporary and reversible. Unfortunately, if this is not the case the prognosis is usually poor. The animal will most likely not regain sight in these cases.

Discover more about canine visual acuity with our article asking what can dogs sense?

The deleterious effects of most toxic substances are a result of the metabolic damage they causes to animals. This often affects the integrity or functioning of one or more of their organs. Certain compounds can damage the animal's nervous system when ingested. Although vision loss is not a common result of poisoning, this damage can result in temporary or permanent blindness. Some examples of toxins which can affect the nervous system in this way include:

• Ethylene glycol (antifreeze)
• Rodenticides
• Lead
• Certain plants
• Some mushrooms

Sometimes intoxication can be a result of ingesting too much of a product which is otherwise considered safe for animal use. An example is ivermectin for dogs and other antiparasitic drugs which can be administered improperly. We place pipette flea treatment on the shoulders of dogs so they do not lick it and ingest the antiparasitic. Doing so can cause neurological effects such as blindness and even death of the animal.

Treatment for poisoning in dogs

In cases of poisoning, it is essential we go to a veterinarian immediately. This will be considered a veterinary emergency and delaying treatment can significantly harm their prognosis. Depending on the cause, it may be necessary to perform a gastric lavage to eliminate the toxic substance. Fluid therapy may be required, but the animal will need to be stabilized to ensure recovery.

Learn more with our article explaining what to do with rat poison in dogs.

Chorioretinitis is defined as an inflammation of the choroid and retina of the eye, the former being a thing layer of tissue in the wall of the eyeball. This inflammation results in rapid unilateral or bilateral vision loss, depending on whether only one or both eyes are affected.

There are various causes of chorioretinitis in dogs, but bacterial, fungal and parasitic infections are the most common. Dogs that suffer from previous systemic diseases, such as leishmaniasis may also be more susceptible to developing this eye condition in dogs. Similarly, dogs that are immunosuppressed due to some type of cancer or an autoimmune disease may develop chorioretinitis as a side effect.

Treatment of chorioretinitis in dogs

Treatment of choroid and retina inflammation is pharmacological, usually through the application of anti-inflammatory drugs or corticosteroids. Efficacy will depend on the severity and the underlying cause. In many cases, vision is restored in a few days or weeks once the inflammation has reduced.

The most frequent cause of sudden blindness in dogs is as a result of an underlying medical condition, including certain diseases. However, it is more common overall for the dog to experience a progressive loss of vision instead of leaving the animal completely blind in a short space of time. While the progression may be gradual, we may not be aware of the vision loss in the dog until it appears as if it has occurred all of a sudden.

The time that can pass from diagnosis of an ocular disease until the dog loses their vision is variable. Duration will depend greatly on each case. It is possible that some dogs go blind in just a few days, while others take weeks, months or years. For this reason, it is common for many owners to think that their dog is suddenly blind when this is not the actual case.

The main pathologies that cause progressive blindness of varying evolution duration are:

• Cataracts: this is a loss of transparency of the lens that prevents the animal from seeing properly. They are relatively common in older dogs, especially in breeds with a certain genetic predisposition, such as the Cocker Spaniel or the Poodle. They can also be a result of other medical conditions such as diabetes mellitus in dogs.
• Glaucoma: glaucoma appears as a consequence of an increase in intraocular pressure, resulting in damage to the optic nerve and causing complete loss of vision. One of the main causes of glaucoma in dogs is also diabetes mellitus, so it is essential to keep control of this disease to avoid problems at the eye level. This includes providing a strict diet and avoiding obesity.
• Sudden acquired retinal degeneration: this condition causes rapid degeneration of the retina, ultimately leading to sudden vision loss. In the early stages of the disease, the eye appears completely normal, which is why it is sometimes difficult to diagnose.
• Congenital abnormalities: some of the most common causes of blindness are closely related to the genetics of the dog. Disorders such as progressive retinal atrophy, retinal dysplasia or congenital blindness due to lens luxation affect some breeds more frequently than others. It is essential to thoroughly investigate which dogs are genetically predisposed to suffer from them and to avoid breeding affected specimens.

If you have noticed that your dog has suddenly lost vision, it is very important that you go to the vet as soon as possible. They will be able to perform the relevant tests and prescribe an appropriate treatment. In certain cases, the blindness may be reversed or progression of vision loss may be slowed.

Learn more about caring for animals with vision loss in our article asking is it cruel to keep a blind dog?

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Sudden Blindness in Dogs, we recommend you visit our Eye problems category.