I have a 2 year old mastiff x and we rescued her from the pound 5 days ago. She only weighed 26kg when we got her and she has started to fill out a bit but I want to make sure she is not over/under fed and getting all she needs to be a healthy weight. She gets fed twice a day, 1 cup cooked pasta or rice, 1/2 cup vegetables carrot or Brussels sprouts. 1/2 cup mackerel or other dog wet food, and 3 to 5 raw chicken necks to clean her teeth. Some advice would be very much appreciated. Thank you

If she's already started to gain weight with the diet you are giving her, continue to feed her that. You don't want her to get fat by putting on weight too fast. Nice gradual weight gain with good muscle toning (light exercise at first) is the way to go.