Cataracts are a common eye condition in dogs, characterized by a cloudy appearance of the eyes' lens. Depending on the cause, they can progress quickly or happen gradually. 

Either way, they can block light from passing through the retina, resulting in vision problems that could lead to complete blindness if left untreated. 

This guide covers everything you need to know about dog cataracts, from what they are to how they are treated and prevented.

Cataracts vs. Nuclear Sclerosis

Nuclear sclerosis is a similar condition, but entirely different. While both conditions can result in cloudy and opaque eyes, only cataracts can hinder vision. Nuclear sclerosis is a normal age-related condition that does not affect a dog’s sight.

What Causes Cataracts in Dogs?

Many pet owners assume cataracts only happen to senior dogs, but that’s not always the case. Genetics, injuries, and other health conditions can all play a role.

Here are the common causes of cataracts in dogs:

Genetics

One of the leading causes of canine cataracts is genetics. Some dogs are born with the condition, while others acquire them later in life. Inherited cataracts typically appear in young to middle-aged dogs and may progress slowly or rapidly.

Dog breeds with a relatively high risk include:

• Siberian Huskies

• Bichon Frises

• Poodle

• Miniature Schnauzers

• Labrador Retrievers

• Boston Terriers

Diabetes

Diabetes mellitus is another leading cause. Affected dogs have a significantly higher chance of cataracts due to increased blood sugar levels.

It happens when excess glucose enters the eye lens and is converted to sorbitol. This draws in water, causing it to swell and become cloudy, resulting in cataract formation.

Diabetes-related cases often develop fast, resulting in complete blindness in just a matter of weeks or months. 

Age

Just like humans, dogs can develop eye conditions as they age. Age-related cataracts usually begin between the ages of 4 and 5, though the exact timing can vary depending on the dog’s breed. 

Cataracts caused by aging tend to develop gradually and do not generally require immediate treatment. However, proper management is essential.

Eye Diseases

Eye diseases such as uveitis, glaucoma, and progressive retinal atrophy can increase the risk of cataracts in dogs. Here’s how they affect the eyes:

• Uveitis. Chronic eye inflammation can have cataracts as one of its complications.

• Glaucoma. The increased intraocular pressure can damage the retina and lens, potentially resulting in cataracts. 

• Progressive Retinal Atrophy. PRA degenerates the retina, causing a release of chemicals that can inflame the eye lens and lead to cataracts.

Eye Injuries and Trauma

Injuries and trauma to the eyes can damage the lens and trigger the formation of cataracts. These can include puncture, scratches, or blunt force. This kind of damage can also result in uveitis, a condition that increases the risk even more.

Other Factors

While not as common as the others above, nutritional deficiencies and toxin exposure can potentially trigger cataracts in dogs. Puppies who don’t receive the right amount of nutrients can develop eye impairments and problems, such as cataracts.

Additionally, long-term use of corticosteroids can also be a potential cause.

What are the Symptoms of Cataracts in Dogs?

The signs of cataracts in dogs often begin with subtle changes in vision. These include:

• Cloudy, Bluish, or Gray Eyes. The most visible sign of cataracts is a cloudy or milky appearance in one or both eyes. This usually starts in the center of the lens and may look bluish, white, or gray.

• Changes in Pupil Size. The pupils of affected dogs can appear dilated, and in some cases, they may even be uneven. 

• Clumsiness and Bumping Into Objects. As their vision becomes impaired, dogs will frequently have difficulty navigating around the house, often bumping into objects and knocking things over. 

• Reluctance to Move and Play. Dogs with vision loss will have significantly reduced activity and willingness to play. They might even hesitate to move, especially at night, in dimly lit rooms, or unfamiliar spaces. 

• Eye Irritation and Redness. In some cases, eye inflammation can cause cataracts in dogs. This leads to redness, eye irritation, pawing at the eyes, and discharge.