Cats and Cataracts
Poor old Bones is getting on a bit now. He's currently 12 years old and not in the best of health, but I'm very pleased to say that he seems to be like the proverbial squeaky gate that goes on forever.
Two years ago he was diagnosed with a degenerative kidney disease and was given, at best, 6 months to live. Regular testing has surprised and astonished us all, as the disease has more or less halted in its tracks.
He's progressively had to have more teeth removed because of a non-descript gum disease, but he still attacks his food (both dry and wet) with enormous enthusiasm.
It was on his latest trip to the vets, to have his final four teeth removed, that the vet noticed something else we really needed to be aware of - cataracts.
Cataracts are a clouding and progressive degeneration of the lens in the eye. They impair vision and can eventually lead to blindness. Most cataracts will progress to obscure vision completely, although it is difficult to predict how quickly that will happen in any individual case.
There are many causes for cataracts including old age, juvenile nutrient deficiency, diabetes and a number of other unavoidable complaints. We are currently assuming in Bones' case the cataracts are due to old age, but this will have to be investigated further to come to a firm conclusion.
Cataracts are usually first diagnosed by the appearance of cloudy spots in pupils of the eyes, although further tests are required to diagnose the stage and rate of progression.
Cataracts are medically classified by location within the lens or by the age of the cat at onset, for instance 'juvenile cateracts' for cats of less than 8 years or 'senile cateracts' for cats over 8 years. From our perspective though, they are more usefully defined by the degree of maturation of the cataract itself, which gives the best indication of how much it will affect the vision.
Surgical techniques have been improved greatly over the past few years and can in many cases lead to a full recovery, however this is still prohibitively expensive and there is no guarantee of success. Surgery is also never without risks, in this case including infection, glaucoma and even retinal detachment.
The short-term success of operations is around 95%, but taking complications into account the longer term success rate shrinks to 70%. With such an invasive and disruptive procedure and a very real possibility of failure, it is not surprising that many owners opt to let nature take it's course, especially in older cats. This is what we've decided with Bones, for now at least.
The almost inevitable result of this course of action is blindness, which initially concerned us a great deal. We asked the vet about blindness in cats, as well as doing some research ourselves, and are happy to find that the general outlook is positive. With a little extra care and attention both cats and dogs can live perfectly happily without sight.
Cats have a superb sense of smell and much better hearing than we do. With the loss of sight comes a sharpening of these other senses, and a blind cat can makes its way around a familiar room with a surprising level of grace and with few mistakes.
Cats in this situation should not be allowed to wander outside alone as they may become panicked and confused in unfamiliar or noisy places, but chaperoned visits to the garden can be very enjoyable for them and leash training is not too difficult for most cats.
Taking all this into account, there are also some compelling arguments for operating too. As the cataract worsens, the lens can sometimes leak proteins into the eye. The body views these proteins as foreign bodies and the immune system mounts a defence, which can lead to inflammation and even infection.
For this reason, cats with untreated cataracts must be monitored carefully for signs of inflammation or irritation and may need occasional medication for the rest of their lives. In severe cases the irritation may be more unkind than the risk of the operation, and then a difficult decision must be made
In the course of my research for this article I've come across several sites claiming that the addition of sulphur to the cats diet can both prevent and treat cataracts, and even a company selling eye drops they claim will cure cataracts. I can't make any judgements on the effectiveness of these treatments, but rest assured I will be speaking to our vet for advice and, if we end up trying these treatments, I'll write a follow-up article detailing the treatment and the results.
Please let us know if you've tried these remedies and what effect you saw.