Cataracts in pets occur for several reasons, the most common one being hereditary. Breeds like Cocker Spaniels, Labrador Retrievers, French Poodles and Boston Terriers are at higher risk.
Cataracts: what are they?
The function of the lens in the eye is to focus and refract light. It is made of tissue fibres that with age become more compact and more dense, thus the lens can appear cloudy. This is called nuclear sclerosis, but the animal is still able to see through the lens.
A cataract is an opacity caused by the disruption of the normal architectural arrangement of the lens fibres or lens capsule. If the cataract is small the pet might be able to see around it but if the entire lens is involved the eye will be blind. If the pet develops cataracts in both eyes, they will be completely blind.
Cataracts: what causes them?
There are several reasons why cataracts develop.
The most common one in dogs is hereditary: these can be congenital (pet is born with it) or develop by the age of around 5 years.
Another common cause in dogs is diabetes mellitus, due to higher sugar levels in the fluids of the eye. This does not happen in cats with diabetes though.
Other causes are trauma and dietary deficiencies.
Do they need treatment?
The short answer is yes. The lens affected by the cataract can slip from the tissue strand that keeps it in place and float around the eye and damage the other structures in the eye. This is called lens luxation. A luxated lens can impair drainage leading to a build-up of pressure in the eye (glaucoma). This is a very painful condition. Cataracts can also begin to dissolve leading to severe inflammation (uveitis) which is also very painful and can also lead to glaucoma.
How are they treated?
Cataracts are treated by a process called phacoemulsification. The lens is broken apart by sound waves and the contents sucked out. An artificial lens is place back in the lens capsule. When the lens is luxated or if the cataract is very mature (in old patients) phacoemulsification is contra-indicated and the lens will be surgically removed.
These procedures are only performed by experienced specialist veterinary ophthalmologists with the correct equipment.
Cataract surgery is an elective procedure and other health problems should be addressed before surgery. It is also quite expensive, and your pet will need to be kept quiet and have eye drops applied for about 4-6 weeks post operatively.
How do I know if my dog has cataracts?
Examine your dog’s eyes regularly. If you notice cloudiness or blue grey discolouration of the eye or if you suspect that your pet is having trouble seeing, get him to the vet. Be aware of conditions like diabetes: your pet will be drinking lots of water and urinating a lot and losing weight in spite of eating a lot.
If there was any trauma to your pets eye it is also better to have your vet check the eye.