We feed our dogs just pellets(kibble, I think you call it). The best we can find in the shops is about $20. We feed them twice a day and just the right amount for their size. But still the silver dapple dachshund keeps putting on weight. We do walks 3-5 times a week and she drinks plenty of water. Snors like a tractor when sleeping. Should I cut down her food, give her more walks or change her food diet?