Don't worry... this happens to almost everyone, especially when dogs are no longer in their puppy stage and their metabolism and energy starts to slow down. I also give Gonzo green beans to fill up, I rinse off and steam frozen green beans. Nutro Natural Choice has a good low calorie food. One thing that most people dont notice is the amount of treats they give their dogs, try to cut down on biscuits and feed baby carrots and pupcorn (only a few calories each) as treats. Frequent exercise is good too just take her out and play ball for 10-15 minutes whenever you can, and walk her as much as possible... you could always have your daughters walk her too

Good luck, I'm sure Casey will lose the weight easily! Especially now that the weather is better