Cataracts are a health issue that can affect any animal, including cats, dogs, rabbits, birds, reptiles and fish.
"The lens is normally clear, allowing light to pass through to focus on the retina. If the protein within the lens becomes denatured, the lens will become cloudy and
affect vision," says veterinarian Dr Gillian Hung.
In addition to the impact on vision, cataracts can lead to severe inflammation of the eye and high eye pressure, or glaucoma, which is a painful condition that occurs as the cataract matures and lens protein leaks out into the eye.
"Glaucoma in people is painful, and has been described as a non-stop throbbing headache. Animals may only show subtle signs, such as sleeping more and being less active, but most likely suffer similar pain as people. Treatment is important to
improve the pet's quality of life" Hung says.
While detecting cataracts in the later stages is easy, as the eye will be cloudy, the earlier stages can vary.
"As the cataract matures, the eye may become inflamed and owners may notice a red eye, watery eye discharge, squinting, pain and pawing at the eye," Hung says.
There are a variety of causes, including aging; inherited cataracts in miniature dog breeds such as poodles and schnauzers; diabetes; congenital and retinal degeneration; eye trauma; radiotherapy for cancer treatment, if the eye is exposed to the radiation beam; and electric shock from chewing electric wires.
"If owners notice any eye problems, they should visit a vet as soon as possible as the condition can deteriorate very quickly," Hung says.
Some preventive measures can be taken. This includes ensuring pets are fed a well-balanced diet and are not overweight. "Fat pets are at increased risk of developing diabetes," Hung says.
Also, make sure that vaccinations for preventable diseases, such as heartworm, are up to date. Illnesses can lead to chronic eye inflammation, which can then cause cataracts.
Pets' cataracts can be removed by the same surgical procedure that is performed on people. Hung says the success rate of this procedure is much higher if it is performed early, and she advises owners not to wait until their pets' cataracts have matured. It is "important that your pet is healthy before cataract surgery," Hung says. "A blood and urine test may be done to assess [the pet's] health, and to check for diabetes. An electroretinogram and ultrasound of the eye is also required before surgery.
"Your pet must pass these tests in order to qualify for cataract surgery, and to ensure the best chance of success."
Hung says advancements in surgical techniques have significantly increased the success of these procedures.
"Pets no longer need to suffer from blindness due to cataracts, and the ability to treat them has helped improve the quality of life for many," she says.
Owners should take younger pets for an eye check up once a year, and to have older animals inspected very six months, Hung says.