Browsing tag: cataracts

Ask a vet online- “My 9 year old GSD has a black disk like cataract in one eye. Can it be removed safely. Would this be expensive to remove? Is this usually done by my vet or a specialist eye vet?”

Question from David Keown
My 9 year old GSD has a black disk like cataract in one eye. Can it be removed safely and what’s the prognosis for a good recovery. Would this be expensive to remove? Is this usually done by my vet or a specialist eye vet? Thanks.

Answer from Shanika Williams MRCVS online vet

Hi David, thank you for your question about the black disc in your GSD’s eye (German shepherd dog).

Firstly I will describe what a cataract is; I do not think that your dog has a cataract but an iris cyst.

A cataract is an area of discolouration in the lens of the eye, the lens sits in the middle of the eye and is usually colourless and clear, it sits just behind the iris (coloured part of the eye). Usually a cataract can only be seen without the use of specialist equipment if it is very large or the lens has dropped out of its correct position and has fallen into the front chamber of the eye.

So what is the black disc?


The black disc that you are describing in your GSD’s eye is most likely to be an iris cyst. Iris cysts are fluid filled black discs of varying size that bud off from another part of the eye. They vary in size (usually few millimetres in diameter) and can move around or are fixed in position; they are usually found at the front bottom half of the eye. I have personal experience of this condition as our family GSD had several mobile iris cysts.

Does my pet need any treatment?


Iris cysts rarely cause a problem to your pet; they are not painful and rarely have any impact of your pet’s vision so we tend not to treat them. It is however important to distinguish an iris cyst from an iris melanoma (benign cancerous growth). Iris melanoma is a condition where there is a slow growing area of black visible within the front chamber of your pet’s eye. Iris melanoma can lead to cataracts, glaucoma (increased pressure in your pet’s eye) and pain. If iris melanoma is suspected then it might be advised that your pet’s eye is removed. Most pets cope incredibly well after removal of an eye, it is considered to be better not to have an eye than to have one that is diseased and causing a lot of pain.

So I would advise that your dog is examined by your own vet and then if required a veterinary ophthalmologist (eye specialist), if it is an iris cyst then your pets prognosis is excellent. If however iris melanoma is suspected then after the correct treatment which may involve eye removal then again the prognosis is good. I hope that this answer has helped you and your dog.

Shanika Winters MRCVS (online vet)

Ask a Vet Online – ‘I have a border collie he has progressive retinal atrophy and now he has a cateract, is there anything that can be done for him?’

Question from Anne Wood

I have a border collie 5 years old. Hes a very frightened dog but he is completly blind in 1 eye and partly blind in the other the vet told me it was progressive retinal atrophy and now he has a cateract on top of his blind eye, is there anything that can be done for him please and thank you for taking the time to read this.

Answer from Shanika Online Vet

Hi Anne, thank you for your question regarding your dog’s eyes and behaviour.

So what is progressive retinal atrophy (PRA)?

As the name suggests it is a condition where there is gradual degeneration of the retina (layer lining the back of the eye). PRA is usually an inherited condition and sadly there is no cure for it, however on the positive side it rarely causes pain.  There is no treatment for PRA at present, there have been some trials of using antioxidants to slow down the degenerative process but the results of this are as of yet inconclusive.

Cataracts are a common finding along with PRA; a cataract is cloudiness in the lens of the eye. The loss of vision caused by the PRA itself means that cataract surgery is rarely advised as there will not be much improvement to vision as a result of the surgery.

How would I know that my dog has PRA and how is it diagnosed?

Owners usually notice a loss of vision in the pet, most noticeable in low light conditions, their pets pupils may appear more dilated with an increased glow/shine (tapetal reflex) from the back of the eye.

A diagnosis is usually made when your vet or ophthalmologist examines your dog’s eyes and notices the damage to the retina.

What can I do for my dog with PRA?

Sadly there is no treatment for PRA itself but as it is a painless condition then it is more a case of trying to help your dog to adjust to his gradual loss of vision. Generally the other senses smell, hearing, touch and taste increase to try and compensate for the one that is deteriorating.

You can take steps to make your home environment easier for your dog with poor or no vision to get around. Keep large pieces of furniture in the same place, use stair gates to block off dangerous areas, when out and about use lots of vocal and physical clues to let your dog know where you are and to provide reassurance.

Dogs are incredibly resilient animals and adjust very well to changes especially when they are gradual. I hope that this answer has helped you to understand a little bit about PRA and how both you and your dog can still lead a happy life together.

Shanika Winters MRCVS

If you would like Shanika to answer your question please Like us on facebook to submit your question www.facebook.com. If you are concerned about your dog please call your vet or use our interactive dog symptom checker

Why cats go blind.

Blind cat showing dilated pupils

Blind cat showing dilated pupils

One of the most common causes of sudden blindness in an elderly cat is due to high blood pressure (hypertension). The increased pressure pushes the light sensitive layer (retina) away from the back of the eye and this can happen literally overnight.

The affected cat will have very widely dilated pupils even in bright sunlight and there might be some blood visible when looking into the eyes. They will appear to be disorientated, bump into things and might vocalise excessively.

Monitoring a cat's blood pressure

Monitoring a cat's blood pressure

The usual cause of raised blood pressure in cats is an excess of thyroid hormone (hyperthyroid) but it can also be due to kidney disease or diabetes. This is why it’s important for the vet to take blood tests to decide which condition to treat.

We monitor cats’ blood pressure in a similar way to human doctors by inflating a cuff just above the paw on a front leg but we listen for blood flow with an ultrasonic probe rather than a stethoscope. Some cats are calmer if the cuff is placed around the tail base. A few readings are usually taken to make sure that the blood pressure has not been raised through stress.

blood pressure kit

Blood Pressure Monitor

Drugs are very successful in bringing a cat’s blood pressure down to normal but the blindness is usually permanent. Cats are extremely adaptable when it comes to finding their way around the house and finding their food but they are not safe to allow outside due to all the dangers out there.

There are a number of other causes of blindness but these generally come on more slowly:

Glaucoma is the same condition as people get where there is an increased pressure within the cat’s eye. This is usually seen as a very angry painful eye and the white of the eye appears red due to the many new blood vessels. Drops can control the condition if caught early enough but if it reaches the stage where the eye is visibly swollen or ulcerated, then removal of the eye (enucleation) will usually be suggested. Glaucoma can be found in just one eye or both.

Cataracts are much less common in cats than dogs and would be seen as a misty or pearly lens. Tests would be required to rule out diabetes which can be a cause.

Tumours within the cat’s eye are occasionally discovered when the eyes are examined with an ophthalmoscope. Loss of vision would be slow to develop in these cases and often in only one eye initially.

If you have a pedigree cat (particularly an Abyssinian) who starts to slowly lose vision early in life, there is a possibility of Progressive Retinal Atrophy (PRA) which is a genetic disease, very similar to the condition in some pedigree dogs. There is no treatment but the cat usually has time to adapt to the slow loss of vision.

Something we hardly ever see these days is Taurine (an amino acid) Deficiency. Modern complete diets have all the taurine a cat needs but it is just possible that a cat fed exclusively on tinned tuna could develop slow onset blindness due to this deficiency. If caught early enough, the loss of vision can be stopped or even reversed.

Most cats adapt very well to blindness and go on to enjoy a good quality of life. Some adapt so well that it would be hard for a casual observer to know they were blind.

If you are worried about any problems with your cat’s eyes, please contact your vet or use our interactive Cat Symptom Guide to help you decide what to do next.

More Useful Information

Examining your pet

Simple ways to check the health of your pet. Vets use these techniques as part of their clinical examiniation.

Medicating your pet

Arming you with the same simple techniques for stress free pill giving.

Worming & Flea Treatment

Information and advice in treating your pet for worms and fleas.