Cocker Spaniels have some hereditary health problems such as PRA and FN, so it is important to buy your puppy from healthy parents that have been tested for these

The main ones are as follows where there are available tests for breeders to use before they breed from their dogs

Prcd-PRA - causes cells in the retina at the back of the eye to degenerate and die, causing blindness there is no treatment or cure for PRA, so it is important to get a puppy from parents that have been fully tested for prcd-PRA. There are 2 tests for PRA one is on the BVA/KC scheme, this will determine at the point of the examination if there are any signs of the onset of PRA, this needs to be carried out annually, the other test is Optigen where a blood sample is tested and will determine whether the dog in clear, Carrier or affected, this is a one off test that can determine the future of not only the dog tested but the offspring of the dog for life (See the table below) 

FN - Familial Nephropathy (FN) Dogs with FN typically develop chronic renal failure between 6 months and 2 years of age, with eventual and sometimes rapid destruction of both kidneys. The early clinical signs are the same as those associated with chronic renal failure due to any other cause. These include excessive water consumption, excessive urine volume, reduced growth rate or weight loss, Antagen FN test is very accurate and specifically identifies normal dogs, carriers and affected, ,again this is a one off test that can determine the future of not only the dog tested but the offspring of the dog for life See table below