Cataracts are the most common eye disorders and cause of vision loss in dogs. The eye lens will sometimes change and include gradual and continuous fibre formation (sclerosis) due to aging. This gives the eye a cloudy appearance. Cataracts can be partial or can include the entire eye lens and can develop in one or in both eyes.
What Causes Cataracts in Dogs?
Age and breed are the most determining factors. The age during which cataracts can occur typically depends on a dog’s breed, but generally speaking it can happen at six years of age for large dogs, and 10 years of age for smaller dogs. When cataracts are age-related, their development is quite slow and linear. Most cases in dogs are hereditary they can also be associated with systemic diseases as well.
Diabetes, for example, is a common cause of cataracts in dogs. Moreover, uveitis, which is the inflammation of the inside of the eye behind the cornea, can often occur when a dog has diabetes. Sometimes, too, the eye may respond to acute or chronic inflammation with an inflammatory cataract, as well.
Hypocalcaemia, a general low level of calcium, often caused by renal failure or problems in the parathyroid, can be another cause for cataracts in dogs.
Breeds Susceptible to Cataracts
Pure-breed dogs often experience cataracts more than mixed-breed dogs, and studies have found that about 60 dog breeds are predisposed to developing cataracts. Some include: American Cocker
Spaniel, Bichon Frise, Boston Terrier, Bull Terrier, German Shepherd, Golden Retriever, Labrador Retriever, Miniature Schnauzer, Poodles, and Rottweilers, among others.
Cataract Signs & Symptoms
Your veterinarian will likely bring cataracts to your attention during a regular physical exam, though there are some signs and symptoms you can watch for.
How cataracts manifest themselves in dogs can vary based on breed, and even environmental factors. Perhaps the most evident sign is a lens opacity in the dog’s eyes. Clinically, this can be detected by veterinarians using a light source at half a meter from the dog’s eyes to see the degree of obstruction of the light reflection by the dog’s eye lens.
Other signs relate to behavior and include less eye contact from your dog, or troubles in finding their toys of food.
Cataracts appear in different shades of colors in your dog’s eyes depending on the maturity stage of the cataracts. As the eye lens thickens with age, the affected eye looks brown to black if the cataract is just beginning to develop. If a cataract is more advanced it looks white to blue—and when cataracts reach the mature stage, they don’t reflect light.
Cataract Prevention
For the majority of cataract cases, there is no real method of prevention. It is important however that dogs (and especially older ones) have regular veterinarian visits so that any change in the dog’s lenses can be detected at an early stage. It has also been proven that antioxidant supplements in a dog’s diet can help maintain healthy eyes for longer periods of time.
Treatment Options
A proper examination performed by a canine ophthalmologist will guarantee the best diagnosis and will help determine whether surgery is needed.
Often, clinically evident changes can develop only when the cataract is half complete and when both eye lenses are affected. However, usually dogs adapt well to vision loss, and most owners decide not to take the surgery path for their dogs.
If Your Dog Needs Cataract Surgery
Ophthalmologists will require a proper history about the dog’s health and eye health and medications the dog has been taking, and they will perform an examination which includes a general body and an ophthalmic analysis. This helps differentiate acute conditions from cataracts that have been developing for a more prolonged period of time. It also helps veterinarians exclude systemic diseases that can manifest with ocular problems.
Cataract surgery involves the removal of the old eye lens and its substitution with a synthetic one. This procedure is necessary if you want your dog to be able to see again, otherwise your dog will lose his/her sight. Cataract surgery has a very high percentage of positive outcomes (90% of the cases).
Cataract surgery is not always advised, however. As previously stated, many factors must be considered, and often dogs just adapt to vision changes.
It’s important that post-surgical treatments are followed for the required time to guarantee a short but effective recovery. Eye drops will be essential to keep your dog’s eyes hydrated, and antibiotics will avoid bacterial infections. Your dog will also need to wear a cone-shaped restraint collar to prevent eye injury.
If the cause of your dog’s cataracts is a systemic disease (like diabetes, for example), it’s likely your veterinarian will focus on treating the general condition first, and hopefully other symptoms or disorders will benefit.
When Your Dog is Blind
Some of the behaviours seen in blind or impaired dogs include a more careful approach to surroundings and a search for proximity towards their owners, because, alongside vision loss, affected dogs are also losing their sense of direction. It’s important that pet owners are patient in letting their dog re-discover their surroundings, and, if necessary, create a new space, without stairs and with suitable fencing. Dogs will make a mental map, so it’s recommended to avoid moving furniture and suddenly putting things in random places. It’s important that your dog’s bowls and bed stay where they have always been, for example.
Some other thoughtful foresight can include placing bells around the house (and on yourself) to help your dog find people, pets and places. You can also place yoga mats on the floor.
Keeping a blind or impaired dog active is essential, too, because it can help dogs more easily learn to use their other senses more, and adapt to their new reality.
Canine Cataracts FAQs
How much does it cost to remove cataracts from a dog?
A visit by a veterinary ophthalmologist can cost around $100-$200. Considering the different tests you may need to understand if your dog needs surgery, prices can be up to $500. Cataract surgery may cost $1500 to $3500 per eye, depending on the clinic, so it may be wise to get quotes from different ophthalmologists.
How do you tell if your dog has cataracts or glaucoma?
Canine glaucoma consists of a group of diseases of the optic nerves which lead to the degeneration of the optic nerve and retina. Glaucoma is a leading cause of irreversible vision loss. It is defined as primary and secondary glaucoma, and secondary glaucoma may be a consequence of cataract surgery (incidence of 5 to 19%). Ophthalmologists will be able to spot the difference, so when in doubt always take your dog to the vet.
Does nuclear sclerosis cause blindness?
Sclerosis often consists of a progressive formation of connective tissue where there should not be. By “nuclear sclerosis” (cataracts) we are defining the progressive formation of connective tissue in the central area of the eye lens. This happens normally with age. As said before, if the sclerosis is significant, it may lead to blindness or impaired vision in dogs.
REFERENCES
Cullen, C. L., & Webb, A. A. (2008). Ocular manifestations of systemic disease. Essentials of Veterinary Ophthalmology, 463. Pp. 223-241.
Eye, A. (2016). Diagnosing Acute Blindness in Dogs.
Gelatt, K. N., & MacKay, E. O. (2005). Prevalence of primary breed‐related cataracts in the dog in North America. Veterinary Ophthalmology, 8(2), 101-111.
Gibeault, S. Vision Loss in Senior Dogs – Symptoms and Management.
Khuly, P. How Much Does Dog Cataract Surgery Cost?
Komáromy, A. M., Bras, D., Esson, D. W., Fellman, R. L., Grozdanic, S. D., Kagemann, L., … & Storey, E. S. (2019). The future of canine glaucoma therapy. Veterinary ophthalmology, 22(5), 726-740.
Murphy, K. How To Care For A Dog Going Blind.
The Institute Of Canine Biology.
Wang, W., Hernandez, J., Moore, C., Jackson, J., & Narfström, K. (2016). Antioxidant supplementation increases retinal responses and decreases refractive error changes in dogs. Journal of nutritional science, 5.