Health

PRA (Progressive Retinal Atrophy) is an inherited eye disease found in many breeds of dogs with varying ages of onset. There are various types of PRA but the one most commonly seen in Cockers is GPRA (General Progressive Retinal Atrophy) also known as prcd-PRA. This results in night blindness gradually leading to total blindness. In Cockers, PRA has a variable age of onset, from as early as 18 months to as late as 7 years. It is inherited as a simple Autosomal Recessive gene, meaning that a copy of the PRA gene must be inherited from both parents for the disease to occur. 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 was that until recently breeders had no way of identifying which category their breeding stock fell into as the only screening test available in the UK (eye testing by a BVA Panellist) could only determine if a dog was clinically clear of the disease at the time of testing. It could not determine whether the dog was a carrier or whether the dog would go on to develop the disease at some time in the future. For some time, a marker gene test for prcd-PRA has been available from the American company, Optigen which gave a good indication of the status of dogs tested. Optigen have recently announced they now have identified the mutation gene which causes prcd-PRA in English Cockers and this test is now available to breeders in the UK & Europe as well as in the US, enabling breeders to identify whether their dogs are genetically clear, carriers or affected with the disease. Information on the test & instructions for sending blood samples to Optigen can be found at www.optigen.com.

Another type of PRA, CPRA (Central Progressive Retinal Atrophy) is also occasionally seen in Cockers and is thought to be inherited in the same way as GPRA as a simple autosomal recessive gene. With CPRA, loss of vison develops much more slowly than in GPRA and some dogs may not completely lose their vision. Because this disease affects the centre of the retina, affected dogs initially have difficulty locating stationary objects in bright light.

It is advised that all breeders should annually eye test their breeding stock under the KC/BVA scheme to eliminate afflicted animals from the gene pool. Afflicted dogs, their parents (proven carriers) & their progeny (genetically carriers also) should not be bred from. More information on the eye testing scheme as well as a list of BVA Eye Panellists can be found at http://www.bva.co.uk/about/canine.html Details of Cockers which have been tested clinically clear & those which have been found to be afflicted with PRA are published in the annual Welfare Report published by The Cocker Club. From 2006, the Welfare Report will also include details of Optigen test results. Other eye conditions are also occasionally seen in Cockers such as Glaucoma, cataracts, persistent pupillary membrane, distichiasis (extra eye lashes), entropion (ingrowing eyelids) and ectropion (sagging, loose eyelids)

Familial Nephropathy (FN), a fatal kidney disease in young Cockers, was unfortunately quite prevalent in the breed in the 1980's until research instigated by The Cocker Spaniel Club established that this was a hereditary condition with a simple recessive mode of inheritance (as with PRA). A Control Scheme was set up by The Cocker Club in the mid 1980's under which, all dogs & bitches known to have produced confirmed cases of FN were withdrawn from breeding and details of these carrier animals were published & made available to members & other breeders so that sensible decisions could be made in the selection of breeding stock. The success of this Control Scheme can be demonstrated by the fact that in recent years, only a small number of confirmed cases have been reported. Research is now being carried out in the US to develop a gene test which will identify carriers of this disease. More info on this research can be found on the English Cocker Spaniel Club of America's website at http://www.ecsca.org and also on the European FN Fund's website here.

An explanatory leaflet on FN & a list of matings that have produced confirmed cases are available from the Defects Co-ordinator, Mrs Lester. Email: quettadene@ukonline.co.uk

Hip Dysplasia (abnormal development of the hip joint) is generally associated with bigger breeds of dog but it can be found in any breed, including Cockers. It can cause lameness & pain in severe cases or produce no noticeable symptoms in minor cases. HD does not have a simple pattern of inheritance (it is a polygenic condition meaning it is controlled by several different genes) and whether an animal will develop HD is also influenced by external factors such as diet and exercise. At present, the incidence of HD in the breed is being monitored to determine if there is a problem. A relatively small number (in comparison to the total number of annual registrations) of Cockers in the UK have been hip-scored to date producing a breed average score of 15. More information on the Kennel Club/BVA Hip Scoring scheme can be found at http://www.bva.co.uk/about/canine.html

Auto-Immune Disease is an umbrella name and covers different immune-mediated diseases of the dog, such as Addisons Disease, Hypothyroidism, Haemolytic Anaemia and others.

Auto-immune problems appear in all the dog population pure bred and otherwise, although some breeds appear to be predisposed to certain conditions. Cockers & Springers have been linked to Haemolytic Anaemia, although research so far does not indicate that the problem is inherited. It seems that environment, age and sex play an important role in an animal developing an auto-immune condition. Research is continuing.