Progressive Retinal Atrophy (PRA)
Progressive Retinal Atrophy (PRA) is an inherited disease of the retina (the “film in the camera”) in dogs, in which the eyes are genetically programmed to go blind. PRA occurs in both eyes simultaneously and is non-painful. There are many different types of inherited retinal degenerative diseases in dogs. PRA occurs in most breeds of dogs and can occur in mixed breeds also. 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. 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. It is recessively inherited in all breeds and PRA is sex-linked and found primarily in male dogs; for this reason all of our male poodles are PRA eye tested and have been tested clear.
Familial Nephropathy (FN)
Familial Nephropathy (FN), a fatal kidney disease in young Cockers, was unfortunately quite prevalent in the breed in the 1980s 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by The Cocker Club in the mid 1980s under which, all dogs & bitches known to have produced confirmed cases of FN were withdrawn from breeding and details of these carrier animals were published & made available to members & other breeders so that sensible decisions could be made in the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 has been carried out in the US to develop a gene test which will identify carriers of this disease.
Phosphofructokinase Deficiency (PFK)
Phosphofructokinase Deficiency (PKFD) is an autosomal recessive disorder that affects Cocker Spaniels. This metabolic disorder does not allow the PFK enzyme to function properly, affecting the energy-producing glycolytic cycle and destroying red blood cells. A lack of oxygen-carrying red blood cells and glucose leads the dog to experience anemia and exercise intolerance. The dog may also feel cramping of the muscles.
PFKD is a recessive disorder, so a dog can be a carrier of PFK deficiency and not display any symptoms associated with the disorder. It is estimated that at least 10% of the cocker spaniel population are obligate carriers, so testing is important to identify carriers. If two carriers of PFKD are bred, there is a 25% chance that the offspring could receive the mutated allele from each parent and be affected by the disease.