hiya,
my cocker is on arden grange and so far so good so cant comment on how much to feed a cocker......
but my 10kg terrier is on half a tin (normal sized tin, 412g) plus mini bite mixer. i feed her two meals a day so she gets quater of a normal sized tin and a handful of mixer in each feed.
my other dog (now gone) was about 21kg and she was on one and a half of the bigger tins (double the normal sized tin) a day split into two meals. so she had 3 quaters of a 824g tin per feed twice a day. she would have eaten more, but she was on steriods and was always starving bless her lol
are you giving your cocker anything else with the chappie? remember that the amount on the tin is only a guideline. the normal sized tins say to give my 10kg terrier 1 and a half tins a day, but she only gets half a tin and a couple of handfuls of mixer (so thats nearly two thirds less than they advise on the tin!!!) and she is perfect weight.....if i gave her any more she would get way too fat!! she always gets a clean bill of health at the yearly vet check.
i think if i were you i would feed according to your dog....if she is getting a bit porky, just reduce the chappie a bit, they usually advise to feed more than most dogs actually need on these tins as you can see by what i have said above about my terrier. obviously you wont want to add the mixer because of her health problems, but i would reduce the amount of chappie a bit.....you can always put it back up again if she starts to get a bit too thin
reading back it sounds like i starve my terrier, but she really is the perfect weight for her size and really doesnt need any more
oh, and all our 'end results' are perfect too
.....like i said before i would highly reccommend chappie for any dog with delicate tummies....
best wishes, vicky