Selina Williams's English springer spaniels Lulu

Dog dieting tips

People are getting fatter – and it is affecting our pet's health as well. We love our pets and like to give them the little indulgences that we enjoy, so pets are gaining weight too. And we like our pets to be “well-rounded” – most pet dogs have considerably more body fat than dogs in the wild, but wild and feral dogs are often closer to the way a fit dog should look.

Being overweight can have lasting consequences and can even be fatal. Studies have shown that overweight dogs do not live as long and are more prone to illnesses that spoil their quality of life, such as arthritis, breathing difficulties, heart problems and diabetes. There is a genuine risk of killing your pet with kindness. 

The way the body works changes considerably in overweight animals. Once an animal is overweight, the working speed of the body slows and they are less active so they do not need to eat much to maintain their weight. It is rare for medical problems to cause obesity in dogs.

The high cost of snacking...

  • A slice of buttered toast to a cocker spaniel provides about a sixth of the daily calorie requirement – or two bags of crisps for a person
  • A sausage to a Staffie is the equivalent of one and a half chocolate bars to a person

My dog always seems hungry...

Fortunately dogs cannot buy chocolate on the way home from work, nor do they have to recover from “bad hair days” with chocolate bars at tea break! Responsible owners should learn to resist soulful eyes.

Dogs are scavengers in the wild and it is natural for them to eat everything they find – whether they are hungry or not. Begging for food is a trick that they quickly learn to exploit – and it is our fault for giving them treats when we are eating.

Only giving them treats “now and then” makes things worse. The scientific name for this is “variable reinforcement” and it is why people play fruit machines – the occasional win makes up for all the losses. The cure is for all the people in the house to learn never to give treats when eating, or to shut the dog in another room at mealtimes. And do not let your dog follow small children who are snacking and “hoover up”.

There is a lot of variation in the energy that different individuals require daily, and feeding packets tend to recommend an over-generous daily amount. Do not be alarmed if your dog generally seems to have quite a small appetite, but do consult your vet if there is a sudden loss of appetite. If you are concerned about your dog's weight, consult your vet. The guidelines below give an indication of how to find out if your pet is the right weight.

Start young

There is evidence that chubby puppies become fat adults. Breeds likely to get joint problems such as poor hips (hip dysplasia) are more likely to develop these problems with overfeeding. Feed your puppy the minimum amount for the body weight recommended on the packet, and monitor body shape as your dog grows. Ask the vet to check at vaccination time.

If an otherwise healthy, happy dog seems reluctant to eat do not be tempted to offer different foods or human foods to coax his or her appetite. You may cause your pet to become a fussy eater. Dogs fed human foods often over eat and become overweight, even on foods relatively low in fat, such as chicken. However, if your dog eats nothing at all for more than 24 hours, contact your vet for advice.

Is my dog overweight?

You cannot tell by weighing a dog and looking at tables of “right weight for breed” because all individuals are different. The only way is to look at body shape and assess body fat. Does your pet have a potbelly? Viewed from above, does your dog have a waist – that is, does the body taper after the rib cage? Can you easily feel your dog’s ribs? No waist, a bit of a paunch, and a well-cushioned ribcage means it is time to take action. The average “chubby” pet is usually at least 15 per cent overweight.

The next step

It is best to start with a trip to the vet. Although increasing exercise is not enough on its own, it is helpful, although your pet will need a check-up for medical conditions that could interfere. Using a special calorie-controlled food from the vet is usually the most effective way of losing weight and well worth considering. Many vets run weight control clinics providing regular check-ups. They are often free of charge, and help to ensure that the diet is working, and that weight loss is not occurring too rapidly.

A food diary

Make a record of everything – including table scraps and treats – that your dog eats for a few days. This is often valuable in highlighting “extras” that your pet is getting. A dog that does not seem to eat much dog food probably still has an appetite for sausages!

Weight watchers!

With calorie-controlled food from the vet, you will be advised how much to feed daily. This will be for the target weight – not the current weight – of your dog. It is best to weigh food out daily, at least to start with. Many dry diets come with calibrated scoops but it is easy to overfill these. You can reduce hunger by feeding two or three times a day, so long as you don't go above the daily recommended amount. If you must feed treats, either take these out of the daily ration, or choose low calorie items, such as a piece of carrot, apple, or rice cake.

If you are not using one of the recommended “calorie-control” foods, but just reducing the amount of normal food, the diet is less likely to be successful. You can try buying a “light” (or “lite”) diet and feeding three-quarters of what is recommended on the packet for your dog's “target” (ie the right, slim) weight. This is usually about 15 per cent less than the current weight, but if you are unsure, check with your vet. However, many of these diets are designed to avoid weight gain, but they are not “reducing” diets to promote weight loss. If your pet is not losing weight after two months, you should consider changing to a diet from the vet.

Remember non-fattening treats too, such as going for a walk, playing a game or simply stroking and giving attention. They last longer than food, help to strengthen your relationship more – and are good for your health too!

Going to the gym?

Don’t expect to walk or run off the calories; dogs are very active creatures, so achieving the equivalent of a “human gym workout” is practically impossible! Increasing exercise alone is not enough, although it is helpful. Start gradually, and be especially careful with elderly pets, particularly in hot weather. Older pets should see the vet first. Little and often is the safest way to start. Try to take your dog out at least twice a day, and start to introduce active games – ambling down the road on a lead is not going to burn off many calories. Increase the activity level at home as well. Buy toys in which you can hide food, such as buster cubes, but remember to deduct the “treat” from the daily food allowance.

How long will it take?

Most dogs that look overweight are at least 15 per cent overweight. So a dog of 40 kilogram(s) (88 pounds) may be six kilogram(s) (13.25 pounds) overweight, and a 12 kilogram(s) (26.5 pounds) dog may be 1.8 kilogram(s) (four pounds) over.

A safe rate of weight loss is one per cent weekly. In the example above the larger dog should be shedding 1.6 kilogram(s) (3.5 pounds) over a month, and the smaller 0.48 kilogram(s) (one pound). Confused? Look for a vet with a weight clinic!

When your dog reaches the target weight, take another look. Is your pet “in shape”, with a waist and a slender tummy? Can you feel the ribs easily? If not, continue with the diet. If the dog is now perfect, do not slip back into old habits, even though your pet may now be more active. You can increase feeding a little – say by ten per cent – and weigh your pet every fortnight to check that the weight is not creeping back. Diets are available that are reduced in calories, but not restricted enough to reduce weight, but which – correctly fed – will stop it creeping back on. Ask your vet for advice.

The diet isn’t working...

Drugs to help with weight loss are now available from vets. However, they are an aid to slimming and cannot be used indefinitely, so lifestyle changes are still essential. There may be mild side effects (such as diarrhoea) but they could be especially useful where weight loss is essential to help a medical problem.

All dogs are different, so if yours is not losing weight on the diet, it may be that your dog burns calories slowly. The daily food intake is above your dog's energy needs and needs to be reduced further. Consult your vet for advice – but first, check that everybody in the house is sticking to the diet. It only takes one person who “feels sorry” for the dog and is cheating to ruin the whole diet! Explain that they are putting the dog's health at risk and may be reducing life expectancy.

Treats you can give

Giving treats, other than for training, is not essential – and for any dog, they do not have to be large! A “treat” should always be given in portions no bigger than the nail of your first finger! Many dogs like crunchy, raw vegetables, such as a piece of carrot or cucumber, or even a piece of rice cake. If you are feeding a dry food, when you weigh out the daily “ration”, set aside a few biscuits from this and give throughout the day.

— Page last updated 26/05/2023