Dr David Gething
A Weighty Issue - Pet Bodyweight
Updated: Aug 21, 2019
Bodyweight is one of the biggest issues in both human health and pet health today, and excessive bodyweight is one of the most common causes of both a shorter lifespan, and reduced quality of life. Excessive bodyweight has a major effect on the function of many organs, especially the heart, liver and the pancreas. Excessive weight can also cause secondary metabolic problems such as diabetes.
The easiest way to determine if your dog or cat is an appropriate weight is to perform a body condition score. Body condition scoring is performed simply by feeling over an animals ribs and backbone. The condition score is rated from 1 (very thin, ribs are sticking out and visible, no fat) to 3 (normal healthy pet, can feel ribs but can't see them) to 5 (very overweight, can't feel ribs even with gentle pressure). This body condition scoring is much more accurate than simply weighing a dog to see if they're overweight, as there is much variation even within breeds of dog.
However, if you have determined that your dog is overweight or underweight, you should then weigh them to make a record that you can use to assess future changes in weight and see if that diet is working.
If you believe your pet is overweight or underweight based on body condition scoring, the first step is to assess how much they are eating. Are they eating a healthy, high quality diet that is appropriate for their age and breed? And are they eating a correct amount of the food? There is normally a feeding guide on the back of the packet to help you judge how much they will need. Also remember to include everything your pet eats, including treats, snacks, natural food, commercial dog food, tidbits off the table. It all adds up.
As vets, most cases of overweight or underweight animals are all about calories – either eating too many, or burning off too few. In many pets, especially cats, it can be difficult to increase their exercise, so it is often easiest to focus on what they are eating.
Just like people, there are no magic pills to fix the problem, but a calorie controlled diet can really help. If you believe your pet is overweight we'd suggest one of the light foods, such as Hills Science Diet Light, or if they are very heavy we'd suggest Hills Prescription Metabolic diet or Royal Canin Obesity. Another great option for dogs is adding some cooked vegetables such as carrots, broccoli, squash or cauliflower – but start off slowly, otherwise you may cause an upset stomach.
We'd also definitely suggest a check-up with a vet before starting any major diet or exercise plan. There are some hormonal causes of weight gain such as thyroid problems and Cushing's disease, especially in dogs.
As mentioned above, exercise is also an important component of weight loss, especially for dogs. Start off slowly, and increase the amount by about 10% per week. We do need to be careful building up, especially with very heavy dogs, and gentle slow exercise is better for fat burning when just getting started. Any play is great – running, swimming, chasing a ball.. and it may also help with that human-animal bond.
Overweight pets are much more common than underweight pets, but being too thin can also occur. Again, we'd suggest checking the amount they eat and correcting if necessary, but being underweight is more likely to be a sign of medical issues. These are often fairly minor, such as intestinal worms, but they can also be more serious – issues like kidney disease and hyperthyroidism can commonly cause weight loss. If you do believe your pet is underweight we'd highly recommend a check with a veterinarian.