My 3 yr old girl Mischka who has always been around 8 lbs started to gain weight. I attributed this on the new kitty being so obnoxious, when she does try to play he will come out of no where and go through her to get at whatever she was playing with first. This has made her very paranoid & has stopped playing. So she is not getting as much exercise. I have had her on purina om for about 2months and she was 10 lbs when I started and now is 11.5 lbs after eating this for a few months she is getting a cup of food a day, Vet said to cut down on the amount to 1/2 cup for another month and see if she looses any. I am worried because I can see she is uncomfortable she doesn't climb as easily as before. Is there medical reasons why she is gaining on a weight management food? Should I wait it out another month to see if things change or have tests done ASAP? Other than being uncomfortable all else with her is normal. I have also noticed that my other male Linx 2yrs seems to be picking on her more often, (the two boys play very rough with each other.) I got the baby because Linx picked on Mischka a lot before and figured another male to rough house with will give Mischka some slack and it did until now. Any ideas???