By Ernie Ward, DVM

I must confess: I believe most pet owners dread hearing me suggest a weight loss plan for their pet. I also confide that I think many veterinarians tremble at the thought of proposing a weight loss plan. To further complicate matters, I believe pet weight loss is as much an art as it is a science. Sure, there are hundreds of scientific studies and decades of research to guide clinical approaches, but in the end, it's the nuances, tweaks, and subtle shifts we incorporate that lead to success … or to failure.

The first two steps

Before we dig into nutrient profiles, calories, and exercise, there are two essential first steps to take. First, the veterinary team must recognize weight gain or obesity in a patient, which is best accomplished by comparing a pet's last-documented weight to its current weight and performing a body condition score. Identifying early weight gain prior to the onset of obesity provides an excellent intervention point. Once the veterinary team establishes any increasing or excessive weight or body fat, they must present this fact to the 
pet owner.

The pet owner must take the second step. We can't help pets until owners are ready to act on their pets' behalf. I've found that many veterinarians become frustrated when clients aren't willing to tackle an obesity diagnosis. After repeated owner pushback, veterinarians often abandon the conversation.

Recognize that clients have their own lives, biases, and priorities. Our obligation isn't to judge whether a client pursues a proposal—it's to offer the proposal. Obesity (like cancer, diabetes, kidney disease, and other chronic conditions) can overwhelm a pet owner, and it may take time or perhaps a medical crisis before they take action. Make peace with reality, be patient, and don't shirk your professional duty to offer the best care for every patient at every visit.

Destination and duration

Pet owners must clearly understand our clinical goals and when we expect to see results. My favorite health journey destination is restoring a physical ability or reclaiming a loved activity. Uncover these hidden quality-of-life cues by asking the client to describe their pet's favorite playtime or what skill they'd like to see revived. Jumping into a car, taking a walk in the park, or hopping on the couch or counter are common goals for my weight-loss patients. I've found that focusing on quality-of-life measurements is more meaningful than shed pounds or shrunken inches.

Focus your weight-loss programs on daily life instead of arbitrary weights and measurements. Research shows that as little as a 6 percent weight loss increases a dog's quality of life.

Duration depends on the amount of weight to be lost. In simple terms, cats can lose about 0.5 pounds per month safely, while dogs can drop 3 to 5 percent of their body weight every 30 days. That equals two months per pound of weight loss in cats and a total weight loss program of six to 12 months for most obese dogs. I've found that if I emphasize a target weight and date that exceeds six months, I lose many clients. That's why 
I started using the step weight-loss program with three-month targets nearly 20 years ago.

Simplified step weight loss

The safest, most successful way to help pets lose weight is to pursue small goals over time. Science tells us that gradual weight loss helps preserve muscle mass and avoid potential nutritional deficiencies. Many pets, especially dogs, initially experience tremendous weight loss during the first three months; then the rate plateaus over time. This normal physiological adaptive response means you must monitor patients closely and adjust the plan accordingly, step by step.

I call this a stair-step weight-loss plan. Think of a flight of stairs, where the goal is to get one from one floor to the next. The starting floor is the dog's present weight, and the ending floor is the dog's ideal weight. There are many ways to move from one floor to another, but the safest and surest way is to take a series of steps that lead to that goal. Too often, veterinarians and pet owners want to take a speedy elevator ride, but quick fixes often result in temporary improvements as opposed to a lifetime of healthy habits. Patience, perseverance, and discipline are required to make meaningful changes. By achieving a series of small goals with close support, lifestyle changes are easier to maintain.

How long does this process take? While no one answer applies to every situation, most dogs should be able to reach their ideal weight in six to 12 months. Healthy dogs that are able to exercise more vigorously may see results faster. Older dogs or those with arthritis or other medical conditions may require more time. In general, dogs that need to lose less than 30 percent of their body weight should reach their ideal or normal weight within six months. For dogs that need to lose more than 30 percent of their current body weight, the time period may be extended to nine to 12 months. Because of their different physiology, cats with obesity require a longer period to reach their ideal weight.

Calculating calories

Every pet weight-loss program begins with calculating calories. Most pet owners don't know how many calories their pet needs each day or how to correctly feed their companions. Most pet food feeding suggestions can't be trusted. Complete and balanced maintenance pet food feeding guides are formulated for adult, unsprayed/unneutered active dogs and cats. That means if you have an older spayed or neutered indoor pet patient, the owner probably is feeding 20 to 30 percent too much if she follows the label.

During every visit, calculate each pet's precise caloric needs based on breed, age, gender, concurrent medical conditions, and lifestyle. A simple starting point is this resting energy requirement (RER) formula: Divide the pet's weight (in pounds) by 2.2, multiply by 30, and add 70. This formula provides a general idea of how many calories a typical inactive, indoor spayed or neutered dog or cat weighing between 6 and 60 pounds needs each day.

A more precise calculation is body weight in kilograms raised to the ¾ power by 70. For more active dogs to maintain weight, multiply by 1.1 to 1.2; for weight loss, multiply by 0.8 (as a start). I've found most cats will maintain weight on RER calories and lose weight at 70 to 80 percent RER. Regardless of the mathematical method you prefer, I urge you to provide this important information every time you see a pet.

Protein, fat, and carbs?!

Determining the nutritional formulation of a weight-loss diet matters. Approach obesity treatment with an open mind; there is no single best diet. Different pets do better on different nutrient profiles. In general, I start my patients off on a high-protein, high-fiber therapeutic diet. I almost exclusively use canned diets with my feline patients. I'm a long-time advocate for low-carbohydrate diets for weight loss, especially in cats. Approximately 10 percent of my clients pursue home-prepared food for their pet.

Palatability and owner perception of food acceptance is critical to program adherence. This is why offering multiple choices is vital and explaining that weight loss is a journey, not necessarily a destination. Cats "addicted" to "kibble crack" may require considerable patience and effort to transition to high-protein canned or home-cooked food. I've found it difficult to help a cat lose weight on a high-carbohydrate diet. Your results may vary.

In short, effective weight loss dietary formulation is a mixture of evidence and experience. After doing this for more than two decades, I can't think of a single patient that remained on the same diet throughout their weight-loss journey. That doesn't mean therapeutic diets don't work; it proves the body is excellent at adapting.

Plateaus and pestering

The No. 1 reasons for weight-loss failure are plateaus and pestering. Plateaus occur when a pet stops losing weight; pestering occurs when neurochemical changes prompt behavioral changes. Both challenges can be overcome successfully.

I developed the step weight-loss program to help mitigate begging behaviors triggered by caloric restriction and identify plateaus as quickly as possible. A more gradual reduction in calories coupled with boosting protein levels seems to lessen most begging. Reweighing every three months allows me to spot real trends and change treatment. When I encounter a plateau, I change the diet or I reduce from 80 to 70 percent RER. (I never reduce below 70 percent RER without thoroughly analyzing the patient's current health status and complete nutritional intake profile or consulting with a veterinary nutritionist.) I'm still amazed at the numbers of patients I see that have been on a "diet food" for a year or more and "aren't losing weight." If you're not seeing weight loss results within 90 days, change your tactic, and change the food.

The last five to 10 percent of weight loss is often the most challenging. Lean muscle mass is built at this time; abdominal fat is reduced. Most pets require an increase in physical activity during the final stage of their weight-loss plan in order to reach their ideal weight. Dogs and cats are naturally lean creatures with long muscles and relatively light skeletal mass. To achieve the desired level of fitness, dogs and cats need to return to the active lifestyles from which they evolved. Dogs kept indoors most of the time have difficulty developing the strong muscles and support tissues required for an ideal healthy body composition without structured daily exercise. Cats must be encouraged to play and engage their "inner predator" daily. Food puzzles, "hunting for food," daily playtime, and lots of environmental enrichment are fundamental to a healthy life for our pets.

Just the beginning

In this three-part series, I've shared some of my best practices as a pet weight-loss expert over the past 25 years. While certainly incomplete and, at times, imprecise, may these writings inspire you to action. We're each called to help animals in our own ways using our unique talents. For me, the pet-human weight-loss journey is still beginning, even after all these years. Remain intellectually curious, observe with an open mind, and always give your best to those we serve.

Dr. Ernie Ward has spent his entire career practicing, writing about, teaching and encouraging better care for animals to earn the title as America's Pet Advocate. Whether he's discussing the dangers of obesity, how to perform a physical examination, dealing with behavioral issues, answering pet owner's questions about nutrition or surgery, or innovating better care for aging pets, his unifying theme is: Do what is in the pet's best interest.