Hi jessica –
It is perfectly okay to mix a grain-inclusive food with a grain-free topper and vice versa. As far as portioning meals, a lot of people struggle with this so you’re not alone. My advice is always to closely monitor the dog’s body condition – pup’s should have their body condition checked once or twice a week, adult dogs can have it checked less frequently such as every month or so. There really is no person or feeding chart than can tell you how much to feed your pup – energy requirements vary drastically between dogs based on factors such as size, breed, age, activity level, environment, etc. etc. You can use the feeding recommendations on the bag as a starting point, but I personally have always found them to be way off. My dogs have always required much more than the amount recommended on the bag and I know several individuals who’ve had the opposite experience – their dogs have required much less than what’s recommended on the bag. It’s just like people – there are some that can seemingly eat whatever they want and remain slim, some that so much as think about a cupcake and they gain 10 pounds and others that fall somewhere in between. Feeding charts on the bag are nothing more than a recommendation. What I do personally is feed my dogs based on calories – many people hate this method however I’ve found it to be the most successful. I know how many calories each of my dogs need per day to maintain optimum body condition and I feed them based on calories – not % of body weight, cups of food, etc. This also accounts for differences in caloric density between foods. It’s not time consuming for me because after years of doing it I, for the most part, have the calorie content of every food memorized or can make a very accurate estimate. As for accounting for the canned topper, in general, one large can of food is roughly equal in calories to 1 C. of kibble. So if you feed one can a day, feed once less cup of kibble or if you feed 1/2 can a day feed 1/2 c. less kibble, etc.
