how do you tell (calorie needs?)

how can i tell how much food, and how many calories Ruckus should consume? since i switched his food he is getting significantly less calories than he used to. however i am feeding him the same amount of food.

maybe you experts on here can help me out. Ruckus is a 33 lbs sheltie. he gets a hour walk a day, and he plays with his toys and fetches a couple of hours a day. he is at a good weight right now. i am only feeding him a cup and a half of natural balance venison and brown rice

depending on activity level, i would say between 1000-1500 calories? But that's just what i do.

If on 'significantly less calories' he starts to noticeably drop weight, then you need to slowly up his food until you find on that food what is right for your dog. Sometimes it takes a bit of fiddling to find the perfect balance no matter what the bag says.

the bag says 3 cups. i dont even feed 2!
i did forget to mention that on the weekends we will be hikeing, swimming, and being very active. do i give him more food on those days?

How is his energy on those days? You may want to feed more so he has more fuel to burn. But only you can really tell what your dog needs.

I'd go by feel. If you can feel his ribs under the skin, but not feel his hip bones on top, he's good. Energy level is secondary, some dogs are more energetic than others so if they need more food you'll be able to tell with the rib test.

on our busy weekends he really does pretty great. but thats on his high energy feed, and he is not on that anymore.