Weight Loss and Diet: The good and the bad
Susan Wynn, DVM, CVA, CVCH, DACVN
We all see overweight pets, and there are many over-the-counter and prescription weight loss diets to recommend as we help owners attempt to manage the problem. Obesity has been documented to affect some 50% of pets in the U.S., so it is often a confounding factor as we develop treatment plans for sick pets. In many of these cases, commercial diets that address combinations of problems are simply not available.
Maintenance and prescription diets are formulated to provide all nutrients in proportion to a calculated caloric intake for any size pet. In other words, a manufacturer’s problem is to produce a food formula that supplies all 40 essential nutrients, no matter the size and food intake of the pet at the other end of the bag. Because we can calculate the approximate caloric intake for any size pet, those 40 essential nutrients are present in an arithmetic matrix tied to the caloric intake.
Reducing the caloric intake for weight loss also reduces intake of these other nutrients. If the amount required for weight loss in an individual dog or cat is less than the amount recommended on the bag, that pet is automatically at risk for nutritional deficiencies, and this is why it is inappropriate to simply reduce the amount you’re feeding if the pet is consuming a pet food. Hence, we use weight management diets in which the other nutrients are present in proportionately higher levels compared to caloric intake so as to prevent nutrient deficiencies.
What about the pet with kidney disease, food allergy or other serious condition for which weight management options may not be available? In these cases, a homemade formulated diet may be the only option.
Meet Scout, an 11-year-old female spayed German shepherd first seen by the nutrition service for weight loss. Her family veterinarian had identified early protein-losing nephropathy (PLN) requiring a low protein diet, but Scout was significantly overweight, with a body condition score of 7/9, complicating her relatively severe osteoarthritis. Scout needed a low protein, low fat diet.
Our initial recommendation was for a prescription geriatric diet with relatively moderate fat and protein levels, eventually reducing her intake to about 1000 kcal daily. After about four months, Scout had reached ideal body weight, but developed hypoalbuminemia, with a serum albumin of 2.2 mg/dL. Our concern was whether her PLN was leading to increased protein loss and a urine protein-creatine (UPC) was performed, which was normal. Scout had no signs of protein loss from other sites, such as the bowel, so we suspected that the caloric restriction of a low protein diet had led to a protein deficiency.
We increased Scout’s caloric intake to 1100 kcal daily. Her serum albumin normalized, but her weight increased by about four pounds, and she was experiencing physical discomfort from osteoarthritis again. The solution for Scout’s problem was a homemade diet. We were able to reduce the caloric density of the food significantly below that of the prescription diet and customize the protein content to maintain a normal UPC and serum albumin. The best part was that Scout still loved the taste, because it was homemade.
One month later, Scout had again reached ideal weight and her serum albumin was normal. A homemade diet was the ideal solution for this dog with complicated diseases.