Have you joined the this site gives a guideline for a moderately active cat). Keep in mind that the water doesn't have any calories, so only include the food you actually give her (some usually ends up stuck to the container the food and water are mixed in). You might also ask the vet whether a liquid food could be mixed with the canned food to keep the calorie content up. Calories are more important to watch than quantity, as some foods are less calorie dense than others. If you have a scale, that's the best way to track whether you are feeding enough.
In Willow's case, she was supposed to get about 180-200 ccs of food per day--the food slurry she was getting had about 1 calorie per cc because we were mixing it with Rebound rather than water. Willow was right around 7 pounds but should have been 7.5 pounds. Keep in mind that ultimately you probably want to feed enough for her to regain weight, not just enough to maintain her current weight. With Willow, I worked up to 40 ccs per serving. She wouldn't tolerate the syringe feeding (it was too stressful for both of us), so she had a feeding tube inserted. She could sleep through the feedings if she chose.
I would start with a goal of 1 can per day and then monitor her weight. How's she doing?
In Willow's case, she was supposed to get about 180-200 ccs of food per day--the food slurry she was getting had about 1 calorie per cc because we were mixing it with Rebound rather than water. Willow was right around 7 pounds but should have been 7.5 pounds. Keep in mind that ultimately you probably want to feed enough for her to regain weight, not just enough to maintain her current weight. With Willow, I worked up to 40 ccs per serving. She wouldn't tolerate the syringe feeding (it was too stressful for both of us), so she had a feeding tube inserted. She could sleep through the feedings if she chose.
I would start with a goal of 1 can per day and then monitor her weight. How's she doing?