Fat cat walking

What body condition score would you give this cat? Photo courtesy of Shutterstock

Obesity is a common disease in cats, affecting almost 50% of the patients seen in veterinary clinics across the United States. Just like in humans, excess fat is accumulated in cats due to an imbalance between the number of calories being consumed and the amount of energy being expended during daily activity. Unfortunately, obesity is much more than just a little extra cat to love! Obesity can lead to many secondary problems including diabetes, arthritis, kidney and pancreatic disease, cardiovascular issues, and infections, all of which can ultimately lead to a reduced lifespan for our four-legged friends. In fact, weight loss alone has been shown to reduce risk and even reverse some of these conditions in cats, particularly with diabetes. 

Fortunately, obesity is a preventable and treatable disease. Avoiding obesity in our pets can be accomplished by choosing quality food, providing an appropriate amount of food and treats, promoting exercise, monitoring weight changes, and adjusting the amount of food that they receive based on those changes. As with other diseases, prevention is the best approach to ensuring the health of our pets, but sometimes we do not realize just how much weight our cats are gaining between visits to the vet.

The ideal weight for your cat is determined by their body condition score (BCS), which is measured on a 9-point scale that your veterinarian will assign based on your cat's silhouette as well as the size and location of their fat stores. Using this BCS, veterinarians can establish an ideal weight for each individual cat, which gives us a reference point for weight loss goals and progress. Cats are considered overweight if they weigh 10-20% more than this ideal weight and obese if that number rises to over 20%.

The first step in weight loss is to determine your cat's ideal body weight based on their BCS. A score of 4-5 is considered an appropriate body condition, so anything greater than 5 is overweight, and anything under 4 is underweight. The general rule is that every 1-point increase or decrease from the ideal BCS score (4-5) is about 10-15% of their weight. For example, if your cat is given a BCS of 6, they need to lose 10-15% of their body weight in order to return to their ideal weight, whereas a cat with a BCS of 9 would have to lose 40-60% of their body weight. With this ideal weight in mind, you and your veterinarian can set a weight loss goal for your cat of losing 0.5-1.5% of their body weight per week. It is important that they do not lose weight too quickly, as we do not want your cat missing out on any essential nutrients that could lead to other problems, like hepatic lipidosis (fatty liver disease). 

Next, you'll need to assess the current food intake of your furry friend; this includes the type of food they eat, the amount they receive, how often they are fed (2-3 times per day, free feeding, etc.), and the number of treats or extra food they are given. If your cat is being given a lot of treats or has unlimited access to food throughout the day, one of the first things you want to do is start feeding them isolated meals, spreading their total daily food ration over 2-3 meals per day. Eliminating treats and extra food from the table is another quick and easy way to decrease calories. Many veterinarians will recommend switching to a veterinary therapeutic weight loss diet that is specifically formulated to decrease calories while still maintaining all of the nutrients that your cat needs. You may also want to consider trying canned food instead of dry food if your cat will eat it, as canned food typically has a lower calorie content due to the increased water content of the food.

Finally, it’s time to put your plan into action. There is an equation that can be used to calculate the number of calories that your cat should be consuming each day, however, many veterinarians do not rely on this alone as it is based on an average and can vary dramatically between individual cats. Somewhat severe dietary restriction is often necessary to achieve these weight loss goals, so you will typically start by decreasing your cat's food intake by around 20% and monitor their progress by weighing them every 2-3 weeks. Monitoring their weight is one of the most important parts of this process, as you may need to further decrease the amount of food they are receiving if they are not hitting that goal of losing 0.5-1.5% of their body weight per week. It is best to use a small gram scale to weigh your cat's food before each meal so you know exactly how much they are getting, as measuring cups and scoops can be inaccurate for measuring kibble.

Measuring your cat’s weight can be done by weighing yourself, holding your cat, weighing again, and then subtracting the difference. This may not be as accurate as your veterinarian’s scale, but will do in a pinch and beats having to get your cat to the vet every week. You can also weigh your cat in the cat carrier, then weigh the carrier alone and subtract the difference.

To help increase your cat's weight loss and keep that weight from being put back on, you can also try various types of enrichment (toys, wands with toys at the end, food mazes, or outdoor catios) to help your cat become more active and burn more calories each day. Once your cat has returned to their ideal weight, it is important to continue these new lifestyle changes and work to find a feeding plan that allows them to maintain that healthy weight.

Obesity is a common problem that many of our pets face, but fortunately, it is something we can reverse with some simple lifestyle changes. With an appropriate amount of quality food, a consistent feeding schedule, and a little more exercise, there is no reason a healthy cat should not be able to return to that ideal weight. Avoiding obesity can help reduce your cat's risk of many life-threatening conditions, improving not only the length of their life but also the quality. Although it may be challenging for both you and your cat to adjust to some of these changes, it will certainly be worth it.