Canine Cataract Diagnosis

A canine cataract affects the lens of the eye. Cataracts can affect dogs of all breeds, although the severity and type of eye condition vary in individual pets. During the diagnosis, the age of the dog is considered essential, to determine the type of cataract. Some pets are also genetically predisposed to develop canine cataracts.

Onset of Cataracts

The lens of the eye is made up of water and protein. Cataracts develop when the water content increases in the lens, causing blurring of vision and loss of transparency.

Symptoms of Canine Cataracts

The most visible symptom of cataracts is a change in the eye color. The eye may appear grayish or bluish in color. This is due to increased water retention in the lens. Pet owners may also notice significant changes in dog behavior, such as reduced playfulness and inability to focus on objects or people.Some dogs may accidentally bump into objects due to lack of clear vision. Canine cataracts may progress from mild to severe in just a few months. Due to this, pet owners should be aware of signs of cataracts, particularly changes to the eye color and redness or soreness around the eye. Prompt medical intervention can avoid blindness and help reduce opacity and blurred vision.

Diagnosis of Canine Cataracts

The first part of the diagnosis involves a physical examination to determine difficulty walking and external changes in the dog’s eye. The vet will also check the dog’s ability to focus on objects. The most common test conducted by the vet is known as the Schirmer Tear Test. This involves placing a tear test strip on the lower eyelid to measure tear production. The test is the least invasive, and takes a minute to perform. The vet will also examine the eye for damage and the presence of any foreign particles.

Other Diagnostic Tests Include:

  • Eye pressure test
  • Internal examination of the eye lens
  • Complete blood count test
  • Electroretinography
  • Ophthalmic ultrasounds

Eye Pressure Test

An eye pressure test is conducted with the use of an instrument called a tonometer. The normal pressure should fall between 10 and 20 mmHg. An elevated eye pressure level indicates eye problems in dogs.

Internal Examination of the Eye Lens

Dogs will be checked using a specific examination called a slit beam biomicroscopy. A tool is used to magnify the macroscopic and microscopic features of the eye. This includes the examination of eye opacity, fluid retention and the anterior chamber of the eye.

Complete Blood Count Test

Several dogs suffer from cataracts as a secondary disease to diabetes mellitus. The blood test determines all components of the pet's blood work, if uveitis-induced cataract is suspected. Moreover, a complete blood count is necessary before any eye surgery is performed.

Electroretinography and Ophthalmic Ultrasounds

Electroretinography is usually conducted to rule out retinal disease. It works to measure the electrical activity in the pet’s retina. An ophthalmic ultrasound may also be necessary to determine the shape and composition of the canine eye before eye surgery is conducted.

Although most pets suffering from cataract are treated with surgery, success depends on the presence of retinal disease and underlying eye conditions. Several pets regain vision once surgery is performed.