Cataracts are one of the most well-known forms of eye disease, appearing as a cloudy or opaque spot that changes the lens of the eye and causes it to lose its translucence. Cataracts may be limited to a small section of the lens, or they may grow to affect the entire eye. Cataracts also can strike one or both eyes, depending upon the cause. If left untreated, cataracts inevitably end up costing the dog its sight.
Many breeds are prone to inherited cataracts, which can be passed along through both dominant and recessive genes. Inherited forms result in what are known as primary cataracts. Affected pups may be born with congenital primary cataracts, which are present when the puppy's eyes open, or else appear before the pup is eight weeks of age. Juvenile, or developmental, primary cataracts appear in young animals up through age four, while late-onset, or adult, cataracts appear in older animals. These latter two categories also are known as secondary inherited cataracts, and they usually develop as a complication of diseases like glaucoma or progressive retinal atrophy.
Most cataracts are caused by genetically inherited tendencies or illnesses. However, cataracts also can result from injury to the dog's eye, exposure to toxins like radiation, electricity, and some medications and from metabolic diseases like diabetes.
Many breeds of dogs are subject to inherited cataracts. The age of onset, how fast the cataracts grow, and whether they affect one or both eyes varies widely from breed to breed. Among the most commonly affected breeds: Afghan Hounds, Akitas, Alaskan Malamutes, American Cocker Spaniel, Australian Cattle Dog, Australian Shepherd, Basenji, Beagle, Bearded Collie, Bedlington Terrier, Belgian Sheepdog, Belgian Tervuren, Bichon Frise, Border Collie, Boston Terrier, Bouvier des Flandres, Brussels Griffon, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Chow Chow, Clumber Spaniel, Collie, Curly-Coated Retriever, Dachshund, Dalmatian, Doberman Pinscher, English Cocker Spaniel, English Springer Spaniel, German Shepherd, German Short-Haired Pointer, Golden Retriever, Gordon Setter, Great Dane, Havanese, Irish Setter, Irish Wolfhound, Italian Greyhound, Jack Russell Terrier, Japanese Chin, Labrador Retriever, Lhasa Apso, Lowchen, Mastiff, Miniature Schnauzer, Newfoundland, Norbottenspets, Norwegian Elkhound, Nova Scotia Duck Tolling Retriever, Old English Sheepdog, Papillon, Pekingese, Pembroke Welsh Corgi, Portuguese Water Dog, Rottweiler, Saint Bernard, Samoyed, Scottish Terrier, Shar-Pei, Shetland Sheepdog, Shih Tzu, Siberian Husky, Smooth Fox Terrier, Soft-Coated Wheaten Terrier, Staffordshire Bull Terrier, Standard Poodle, Standard Schnauzer, Tibetan Spaniel, Tibetan Terrier, Welsh Springer Spaniel, West Highland White Terrier, Whippet, Wire-Haired Fox Terrier and Yorkshire Terrier.
If a cataract is small and located on only one eye, it won't affect your dog's vision to any great extent. Most cataracts, however, grow either slowly or rapidly and end up covering the affected eye and eliminating its vision. In congenital cases, the cataract may be absorbed by the eye as the puppy ages, resolving the problem. In other cases, most cataracts can be successfully treated through surgery. The decision whether or not to operate is made based on factors such as whether the cataracts are progressive, how severely they are affecting the dog's vision, and the dog's overall physical condition and temperament. When surgery is performed, the dog must be kept confined and as quiet as possible for at least one to two weeks post-surgery.