Spotting and preventing weight gain in dogs and cats

This guide was AI-drafted from Wikipedia (CC BY-SA) and reviewed before publishing.

Why weight matters for your pet

Carrying extra weight puts real strain on a pet's body. It can make everyday movement harder, put pressure on joints, and affect the heart, lungs, and other organs over time. Overweight pets also tend to have a shorter, less comfortable life than those kept at a healthy size. The good news is that weight gain is one of the most preventable health problems in dogs and cats, and small changes at home can make a big difference.

How to tell if your pet is overweight

The best tool you have is your own hands. Run your palms gently along your pet's sides - you should be able to feel their ribs without pressing hard, but they shouldn't be sticking out sharply. Looking from above, most healthy dogs and cats have a gentle waist behind the ribcage. From the side, the belly should tuck up slightly rather than hang down.

This hands-on check is called a body condition score, and vets use a version of it at every check-up. If you are unsure what you are feeling for, ask your vet or vet nurse to show you - most practices are very happy to help, and many offer free weight clinics.

Common causes of weight gain

The most straightforward cause is simply taking in more calories than are burned off. This can creep up gradually through slightly too-large meal portions, frequent treats, or titbits from the dinner table. It is easy to underestimate how quickly small extras add up, especially in smaller breeds and cats.

Neutering can lower a pet's energy needs, so their food intake may need adjusting afterwards. Reduced activity - whether due to age, bad weather, or a change in routine - can also tip the balance. Occasionally, an underlying health condition such as an underactive thyroid can contribute to weight gain, which is another reason a vet check is worthwhile if you notice a change.

Practical steps to help your pet stay trim

Start by measuring meals accurately rather than estimating. Feeding guides on food packaging are a useful starting point, though your vet can advise on the right amount for your individual pet's age, size, and activity level. Swapping some treats for low-calorie alternatives - such as small pieces of carrot for dogs - or simply reducing the main meal slightly to account for treats can help.

Regular exercise suited to your pet's age and breed is just as important as diet. For dogs, consistent daily walks are valuable. Cats benefit from interactive play sessions that encourage them to move. Puzzle feeders and food-dispensing toys can also slow eating and add a little activity to mealtimes for both species.

Keeping track over time

Weighing your pet regularly is one of the simplest ways to catch gradual changes before they become a bigger problem. Many vet practices will let you pop in to use their scales at no charge. Keeping a note of the weight every month or so gives you a useful picture of any trend.

Photos taken from above and from the side every few weeks can also help you notice changes that are easy to miss when you see your pet every day. If you spot a steady upward trend, it is worth raising it at your next vet appointment rather than waiting.

When to speak to your vet

If your pet has gained weight noticeably and you cannot identify an obvious cause such as a change in diet or activity, it is a good idea to book a vet appointment. A vet can rule out any underlying health conditions and put together a safe, tailored plan to help your pet lose weight gradually.

Never put a pet - especially a cat - on a strict crash diet without veterinary guidance, as rapid weight loss can be harmful. Your vet or vet nurse is the right person to set realistic targets and check in on progress. Most practices are very supportive and non-judgmental about weight concerns.