Overweight Dogs and Cats: How to Tell and How to Help Them Slim Down

How to check your pet at home

The scale tells you the weight, but not whether that weight is right for your pet's frame. Vets use a body condition score instead, most often on a scale from 1 to 9. A score of 1 is severely thin and 9 is severely obese. For dogs, a score of 4 or 5 is ideal. For cats, 5 is ideal, although a score of 6 may be acceptable in some cats, especially older ones. You can do a simple version at home in three steps.

• Feel the ribs. Run your flat hands along both sides of the chest, just behind the front legs. If the ribs feel like the back of your hand, the body condition is probably good. If they feel like your knuckles, your pet may be too thin. If they feel like the soft, fleshy part of your palm, or you have to press to find them, there is likely too much fat.
• Look from above. A healthy dog or cat has a visible waist behind the ribs. An overweight pet looks straight-sided or wider in the middle.
• Look from the side. In a healthy dog, the belly tucks up behind the ribs. In cats, look for only a small fat pad on the belly. A rounded, sagging belly and fat over the lower back and the base of the tail are signs of excess weight.

Long or thick coats hide a lot, so trust your hands more than your eyes. Weigh your pet regularly as well. Small dogs and cats can be weighed at home on a baby scale, or by weighing yourself with and without your pet in your arms. Your vet clinic will usually let you use its scale too.

Why extra weight matters

Fat is not just stored energy. Fat tissue is active and releases substances that cause low-grade inflammation throughout the body. That is why vets now treat obesity as a chronic disease rather than a cosmetic problem. Compared with lean pets, overweight dogs and cats have a higher risk of the following problems.

• Osteoarthritis and faster wear of the joints. Extra weight also makes existing joint pain worse. See our guide to arthritis in dogs.
• Diabetes
• Heart disease and high blood pressure
• Bladder stones in dogs
• Some cancers
• More risk during anesthesia and surgery
• Skin and coat problems in cats

Weight also affects how long pets live. In a lifelong study of 48 Labrador Retrievers, one dog in each pair was fed 25 percent less than its partner from puppyhood. The leaner dogs lived significantly longer, and signs of chronic disease appeared later. Being even moderately overweight may shorten a dog's life by close to two years. In cats, one study found a 2.8-fold higher death rate in obese cats aged 8 to 12 than in lean cats of the same age.

Rule out medical causes

Most pets gain weight because they take in more calories than they burn. Sometimes an illness plays a part. In dogs, an underactive thyroid gland and Cushing's disease can both lead to weight gain. Read more in our guide to hypothyroidism in dogs. A pet that gains weight while eating no more than usual, or whose belly swells, should see a vet before any diet starts.

Spaying and neutering change appetite and energy use. In one study, male cats with free access to food ate more for months after neutering and gained about 20 percent of their body weight, mostly as fat. Neutering is still the right choice for most pets. It is simply a good moment to review portions with your vet. Our guide to spaying and neutering cats covers recovery and care.

Make a weight loss plan with your vet

Start with a vet visit. Your vet will confirm that your pet is overweight, check for medical problems, set a realistic target weight and work out how many calories your pet should eat each day. Simply cutting down the amount of your pet's current food is not a good plan. Ordinary food is balanced for a full portion, so a much smaller amount can leave your pet short of protein, vitamins and minerals over time. Vets often recommend a food made for weight loss, fed in a measured portion at set meal times.

Slow and steady is the goal. A healthy rate of loss for dogs is about 1 to 2 percent of body weight per week. For a 30 kilogram dog, that is about 300 to 600 grams a week. Cats should lose weight more slowly, no more than 1 to 2 percent a week, and many vets aim lower. Weigh your pet every two weeks or so, and see your vet about once a month to check progress. If the weight is falling too fast or not at all, the plan needs adjusting.

Food, treats and portions

• Measure every meal with a measuring cup or, better, a kitchen scale. Small extra handfuls add up.
• Feed set meals instead of leaving food out all day. Free feeding is a major cause of weight gain in cats.
• Keep treats to no more than 10 percent of your pet's daily calories. For example, an 8 pound (about 3.6 kilogram) cat at a healthy weight needs only about 20 calories a day from treats.
• Use part of the daily food ration as treats and training rewards, and count chews and table scraps too.
• For cats, ask your vet about wet food. Canned food is mostly water and is often higher in protein and lower in carbohydrates than dry food.
• Make meals last longer with puzzle feeders and food toys.
• Make sure everyone in the home knows the plan, so your pet is not fed twice.

Many people show love with food, and pets learn to beg for it. Try replacing some treats with attention your pet enjoys, such as a walk, a game or a brushing session. More practical feeding advice is in our guides on how to feed your dog and how to feed your cat.

Exercise

Exercise helps your pet keep muscle while losing fat, and it is good for the mind too. For dogs, start with the walks your dog already manages, then make them a little longer or more frequent over several weeks. Heavy dogs and dogs with joint pain need a gentle start, and your vet may suggest a rehabilitation or physiotherapy plan. For cats, aim for at least two play sessions of 10 to 15 minutes a day with a wand toy or a toy they can chase. Cat trees, shelves and scratching posts also encourage climbing and moving around.

Why crash diets are dangerous for cats

Never put a cat on a sudden starvation diet, and never try to force weight loss by offering only a food your cat refuses. When a cat eats too little, its body sends large amounts of stored fat to the liver. The cat's liver cannot process it all, and fat builds up inside the liver cells. This condition is called hepatic lipidosis, or fatty liver disease. It can be fatal without prompt treatment, and it is much more common in overweight cats.

An overweight cat that stops eating needs to see a vet promptly, even if it seems otherwise well. Signs of fatty liver disease include refusing food, hiding, drooling at the sight of food and a yellow tinge to the gums or the skin of the ears. Treatment usually involves a stay in hospital and feeding through a tube, often for about a month at home afterwards.

When to see a vet

• Before starting any weight loss plan
• Your cat refuses food, especially if it is overweight
• Yellow gums, eyes or ear skin
• Weight gain while eating normally, or a swollen belly
• Drinking and peeing more than usual
• Stiffness, limping or reluctance to jump or climb stairs
• Weight loss that is too fast, or that you cannot explain

Keeping the weight off

Reaching the target weight is a great step, but keeping it is often harder. Once your pet is at a healthy weight, ask your vet for a maintenance portion and keep measuring food and counting treats. Some cats, especially those that beg and are not very active, do best staying on a weight control food with slightly larger portions. Keep weighing your pet once a month, and act early if the numbers start to creep up again.

At Paw Squadron, every rescued animal starts with a vet check, deworming and treatment against fleas and other parasites. A vet visit is also the right starting point for your pet's weight. Once a rescued dog or cat settles into a home with regular meals, it is worth weighing it every few weeks in the first months, so you can adjust portions early.

For more practical guides on feeding and everyday care, browse PawPedia. If you adopted your pet from us and have questions, write to us from the Contact page.