Cocker Spaniels do need a reasonable amount of care when it comes to their grooming requirements. In addition to a regular brushing, they should be stripped out (three or four times a year) by a professional groomer.
Regular attention also needs to be paid to the hair around their ear passages and beneath the ears. Any excess hair should be removed regularly to ensure a proper flow of air in and around the ears.
Likewise, the excess hair around their feet and between their pads should also be removed on a regular basis.
For further help and useful information on the grooming needs of your Cocker Spaniel, we can highly recommend Cocker Spaniel (Collins Dog Owners Guides) by Lesley Scott-Ordish.