Cocker’s suffering from this disease have normal sight for the early part of their lives, their sight then deteriorates and the first noticeable sign is often difficulty seeing well at dusk and at night.  Finally, the condition leads to total blindness.

In Cockers, PRA has a variable age of onset (before symptoms are noticed), from as early as 18 months to as late as 9 years. It is inherited as a simple Autosomal Recessive gene, meaning that a copy of the faulty PRA gene must be inherited from both parents for the disease to occur in an individual.

PRA can be detected by visual examination of the eye (by a qualified veterinary ophthalmologist) only when the disease is readily apparent, the KC/BVA Eye Test cannot and does not detect affected dogs (without symptoms) or dogs, which are carriers of the disease but not affected themselves. Full information about the scheme is detailed below.  If you would like to find a vet who is qualified to conduct an eye test please visit the  BVA - Website  (there is a link with the list of panellists at the bottom of the page).

PRA can also be detected by DNA analysis.  DNA testing (using a blood sample) can be undertaken as soon as a puppy is old enough & big enough to have blood drawn.  The test is able to detect whether a dog is affected (but perhaps symptom free at the time of testing), whether it is a carrier (will not ever be affected but is capable of passing the disease onto it’s offspring) or whether the dog is clear of the disease.

With recessive conditions like PRA, there are 3 genetic categories, affected, normal and carriers. Affected animals have two copies of the faulty PRA gene, one inherited from each parent. Carrier animals have one faulty copy of the PRA gene but appear perfectly healthy and cannot be distinguished from normal dogs by eye screening. Normal animals are entirely free of the faulty gene.

The difficulty is that breeders have no way of identifying which category their breeding stock falls into as the only screening test available in the UK (eye testing by a BVA Panellist) can only determine if a dog is clinically clear of the disease at the time of testing. It cannot determine whether the dog is a carrier or whether the dog will go on to develop the disease at some time in the future.

For more information about OptiGen testing for prcd-PRA please visit OptiGen's website.  For more information on PRA please see here.

All Powerscourt cockers are tested under the KC/BVA Eye Scheme for clinical evidence of PRA (even if the are DNA prcd-PRA clear). 

Whilst we acknowledge the limitations of the scheme we are still of the opinion that testing Cocker's for hereditary eye disease is important.  As already stated the scheme can't detect carriers but statistics (from the BVA) show that cases of eye disease have been reduced from 20% to 1% in dogs submitted for testing, this is proof enough if proof were needed that the scheme makes a valuable health contribution to the future wellbeing of dogs.

Please note, it is not common or indeed useful for baby cocker puppies to be eye tested, if any breeder tells you that the pups have been eye tested then you need to ask a few more questions!   When buying a puppy you need to ensure that BOTH parents have current clear eye certificates and/or OptiGen results.

Another inherited eye disease found in cocker spaniels is Glaucoma. Glaucoma is the elevation of pressure inside the eye, known as intraocular pressure (IOP) beyond a specific point at which vision is compromised or is no longer possible. Glaucoma is a frequent cause of blindness in humans and animals.

The eye examination (called gonioscopy) for Glaucoma is only required once in a dogs life because it's not a progressive disease, the pre-disposition for this disease is either evident or not evident and can be detected the first time a dog is specifically examined for this disease.  

The examination for Glaucoma is a visual examination conducted by a qualified veterinary ophthalmologist.

Inheritance of Glaucoma depends entirely on the severity of goniodysgenesis in both parents - a slightly affected dog mated to clear bitches will not produce puppies affected with Glaucoma.

Gonioscopy is not routinely performed as part of the KC/BVA eye test, this test must be requested separately (and needs to be performed prior to the standard KC/BVA test.)  All Powerscourt cockers are routinely tested for Glaucoma at 12 months of age (this test needs to be done only once.)

By John Foster BVSc, CertVOphthal, MRCVS

Eye disease comes under the spotlight 

Perhaps the most important sense to us is sight. That goes for animals too, but in some cases they have other well-developed abilities, which make up for any deficiency. Just like us animals get old and have difficulty focusing, may get cataracts or receive injuries, which can blind. Of more significance though are eye conditions of an inherited nature (those which are passed down from parents to young). Complete blindness from birth or developing in young adulthood can make getting about and finding food a bit difficult, however well-tuned their noses and ears are. It's for these reasons that a scheme was jointly developed by the British Veterinary Association (BVA), the Kennel Club (KC) and the International Sheep Dog Society (ISDS) in an attempt to find those dogs affected by recognised inherited eye diseases which should not be bred from.

Unfortunately for dogs there are many inherited eye diseases from which they may suffer. Some cause only minor problems such as discomfort or distorted vision, while others lead to progressive blindness, severe and sudden sight loss or pain. To make matters worse these diseases go by long and strange sounding names. Before discussing some of these inherited eye diseases a little basic anatomy will help draw a clearer picture. Then by passing through how these bits work and on to how dogs are affected we can tie all the information together.

Structure and function 

The eyeball is a remarkable thing. It starts life as a piece of brain, borrows a bit of skin to make the lids and the 'window' of the eye, called the cornea, turns itself inside out and in dogs is ready to see things within 11 weeks of conception. Now, that's magic! 

We all know what the eyelids do. They protect the eye and sweep tears over the cornea to stop it drying out. The cornea is an extension of the sclera (the white part of the eye) but with perfectly arranged cells so that light travels through unhindered. If we follow this imaginary shaft of light deeper into the eye, it travels through a liquid, the aqueous humour, to the lens. The lens focuses the light, or more correctly the image, onto the retina which is where everything really happens. All the other eyeball structures have but one purpose, to get that light beam to the retina in as perfect a form as possible and continuously. So, just like film in a camera, the retina acts as the receiver of the moving image and transmits it down the line to the brain.

Even after this description there are some parts that have not been mentioned. Overall, the eye's make up is similar to an onion. It has several skins, more correctly referred to as 'coats', which contain and feed the important internal functions. One part of the latter is the iris, that fascinating circle of colour so popular with poets as well as ophthalmologists. Last, but by no means least, is the vitreous humour, a jelly-like substance occupying the largest space within the eyeball and in a sense keeping it 'inflated'.

Important inherited eye diseases

There are common diseases of the eye and there are important diseases of the eye, but fortunately no common important diseases of the eye. That's common' in the sense of affecting a large proportion of dogdom. That's not to say when any of them do occur they're not significant, because they are for the individual sufferer and for the owner or breeder of the dog.

Having said that, one of the better known inherited eye diseases is referred to as PRA. These letters stand for progressive retinal atrophy, a form of worsening blindness affecting the light-sensitive portion of the eye.

Two other worrying conditions occur in the same area and can be equally blinding but are not progressive (meaning advancing). One is called Collie eye anomaly and the other retinal dysplasia; and this is where we get into problems with terminology. Much as expected, the first affects the Collie breeds and is seen as a distortion in the normal anatomy of the retina and other deeper structures. It's called an anomaly' because its appearance is of a gross irregularity, even to the point of holes or pockets appearing where they certainly shouldn't be.

Retinal dysplasia, sometimes called 'folding', is different again. Put crudely it appears much as a room wall looks after the work of a poor quality paperhanger bubbled.

As described in 'structure and function', further forward in the eye lies the lens.

The dog, curiously enough, doesn't really needs its lens for seeing; it doesn't read newspapers, watch much TV, or drive a car. Most seeing is done by the focusing effect of the cornea; it's only for close accurate work you need a lot of lens activity. Nevertheless, if there is any distortion or opacity in the lens then sight can be severely upset. One such affliction is cataract. Cataract is the clouding of the lens and when taken to the extreme looks as though the pupil has become bluish or greyish, or even has the texture of mother- of-pearl. Inherited cataract is seen in a large number of breeds and can be non-progressive, and therefore minimally sight affecting, or can be progressive and blinding. Cataract is the clouding of the lens and can be blinding.

The last important condition to be looked for is glaucoma. Glaucoma is where the pressure of the aqueous humour within the eye rises above its normal level mainly due to the fluid's inability to escape into the bloodstream. It is a painful and sight- disturbing condition which, left untreated will eventually be blinding.

Inherited eye diseases are in the main transmitted by both parents, only rarely by either the mother or the father, so it's not fair to go besmirching the reputation of one or the other alone. By mentioning only five inherited diseases I may have given a false impression, because in reality there are many other inherited eye diseases to watch out for.

Need I be worried?

Most breeds have some eye abnormalities, of greater or lesser importance. Understandably, the more abnormality is looked for, the more is found, so there is little room for complacency. At the same time there is absolutely no point in burying one's head in the sand and pretending it will all go away or that it doesn't exist. It's far better to get that litter, or that bitch you've always fancied having pups from, checked sooner rather than later.

How do I get my dog's eyes examined?

There are 40 or so BVA panelists throughout the country and their names and locations will be known to vets in practice. Should you need to have your registered dog examined under the scheme, first consult your own vet, who may wish to carry out the initial examination. He or she will be able to tell you about the next steps: making an appointment with the panelist and taking the dog's registration documents with you; the need to have time in hand for the journey it may mean going 50 or more miles, and once there having to wait while drops are put in the dog's eyes and allow them time to work to make the pupil large enough to see all the structures within.

The BVA/KC eye scheme

THE detailed eye examination is performed by veterinary surgeons, generally in practice, who are specially appointed panelists by the British Veterinary Association. The examination is designed to identify all the abnormalities within the eyeball and associated structures, including the eyelids (of which the dog has three, upper, lower and one called the nictitans or 'haw'). Additionally the size and positioning of the eyes is recorded. 'All abnormalities' covers known inherited, congenital, non-inherited and acquired problems, diseases and deviations from anatomic normality.

Pedigree dogs registered with the Kennel Club, and dogs registered with the International Sheep Dog Society are eligible under the scheme. Puppies can be tested up to the age of 12 weeks and should be retested annually as some diseases become detectable with age.

Details of the BVA/KC/ISDS Eye Scheme including breeds affected, conditions and a list of panelists is available from the BVA, 7 Mansfield Street, London W1M OAT.  Visit their website: BVA

Eye testing success

IT is now over 20 years since the International Sheep Dog Society initiated its Eye Testing Scheme and in those early days the incidence of the progressive retinal atrophy (PRA) in dogs tested was higher than 14 percent. After 20 years of testing the incidence is now less than one quarter of 1 percent. This is an undoubted success story, a success attributable to the BVA and its eye panelists on the one hand, and the members of the ISDS on the other.