I am currently on a diet to lose weight. My clients reading this are probably laughing because, while I am tall, I have never been particularly wide. However, we all know how we feel better than anyone else can, and I know that at 183 pounds I have heartburn, trouble sleeping, achy joints, and less energy than I do at 165. Some of us carry more fat in the abdominal cavity (visceral fat), and others deposit more under the skin first.
I bring that up only because it gets me thinking about diet and weight in our patients. We want to do what is best for our pets and one of the levers of control we have as owners is the diet we feed. Let’s look at a little bit of research into feeding and see what we can learn.
I start with a very important study by Dennis Lawler’s group at Purina. In this study, 48 Labrador puppies were paired up with litter mates based on size and sex at 6 weeks of age. They were fed puppy food until 3¼ years old and then adult food until they passed away. They were left unneutered unless treatement of disease required neutering, in which case they neutered the pair. One dog was allowed to eat whatever it wanted each day. They then weighed that amount, and fed 25% less to the other dog in the pair on the following day. Thus, half of the dogs ate 25% less than their pair.
Lawler’s study showed that the average restricted dog had better body condition (normal vs obese), lived longer (2 years) and healthier (less joint pain, later development of cancer). They were all eating the same diet. Just some dogs were eating too much. This study showed that one of the most important things we can do for the health of our Labradors is not overfeed them. That means a body condition score of 4 or 5 out of 9 is ideal. At that body condition, they have a nice waist, you can’t feel fat on the ribs and they don’t have fat pads on the shoulders or hips, but they are not so skinny that the ribs stick out.
A large group of veterinary hospitals performed a review of their records for another study that showed that these findings generalize to all breeds. For example, Yorkshire terriers with healthy body condition live 4 years longer than Yorkies with obesity.
As for cats, we do not have as many good studies. I will keep looking for more. But we do know that overweight cats are more likely to get diabetes, joint disease, and skin conditions. We know that maintaining cats in a healthy body condition prolongs the healthy part of their life. Unfortunately, as cats age they often lose body mass and that is associated with worse outcomes. We would like to learn how to help those cats too.
So, why can’t dogs and cats just eat their food and stay a healthy weight? Do weight loss foods help? I will get to these questions in a future blog post, but for now take as a recommendation to pay close attention to the body condition. You want to back off on the food, treats or table scraps when you notice your dog getting padding on the ribs. You might need to feed meals to prevent your cat from getting overweight. An automated feeder that feeds measured meals can help with cats, as they can get very annoying in the morning when you feed them meals, trying to train you to wake up earlier and feed them.
Keeping a normal weight on your pet is more important, in general, than the choice of product you feed. But I think there will be interesting things to talk about in the next post on this topic, where we discuss the reward system and its role in overweight.