At first, feeding your pet seems like a simple concept. Scoop out food, place in bowl, done. But if it were really that simple, how come we spend countless hours researching, debating, and reading about pet nutrition? Truth is, getting your pet’s diet just right means being aware of all the different factors that go into the right nutritional plan:

• Health status of the pet
• Current weight
• Age
• Breed
• Lifestyle

Take, for example, a cat named Charlie. At nine, he seemed to have a new lease on life- after being a bit of a couch potato, he couldn’t keep still- zooming around at all hours, and after years of being a bit on the larger side, he slimmed down to a svelte ten pounds.

Then nine.

Then eight.

His owners, assuming Charlie was simply experiencing a midlife burst of energy, gave him more food. It seems like a reasonable approach- but it didn’t fix Charlie’s weight loss. In this case, his weight loss and high energy was a byproduct of an undiagnosed medical condition. By the time his owners brought him to the vet, he was quite underweight, a symptom of his untreated thyroid tumor. With the right medication- AND the right food- he stabilized at his ideal weight.

Charlie’s thyroid disease is a good example of the complicated relationship between food and health. Does food cause health problems? Heal health problems? Maintain good health? The answer is, all of the above!

Weight: More than just a number

When performing a physical exam, the pet’s weight and their diet are noted. But knowing that a pet weighs twenty pounds doesn’t mean anything without some additional context- are we talking about a chihuahua or a lab mix? How does that number compare to the pet’s ideal weight?

Many veterinarians use a scoring system called the Body Condition Score. They use their eyes to assess the pet’s waist (or lack thereof), how visible the ribs are, and how much of a belly you can see from the side. They also use their hands to assess the amount of padding over the ribs. Putting those two together, they assign a number between one and nine. One is emaciated, nine is morbidly obese, and five is ideal.

In a world where half of the country’s pets are overweight, you would probably not be surprised to know that the most common numbers assigned are six or seven. This triggers a conversation about weight management, diets, and exercise. But what happens when a pet is less than their ideal weight?

Assessing the underweight pet

1. History. When a pet’s body condition score is four or less, their history becomes very important. Have they always been on the lean side or have they recently lost weight? Has anything changed in their life- a move, a new food, a new pet? Getting a detailed health history helps the veterinarian figure out if this is primarily a problem with the pet not getting enough calories, or if it’s an indicator of a potential health problem.
2. Diagnostic tests. When a pet is dealing with an unexplained weight loss, vets use all of these clues to figure out whether or not they need to run some additional tests to look for health conditions. Diseases such as diabetes, kidney disease, and- as in Charlie’s case- hyperthyroidism can be identified with some very simple bloodwork, allowing intervention and treatment if caught early. Others, such as certain cancers, may take more targeted diagnostics to identify. In all of these cases, unexplained weight loss is one of the earliest things noticed.
3. Nutrition Plan. Once the status of the pet’s health is known, picking the right food becomes clearer. Is this a very active pet who needs a more calorie-dense diet with lots of high-quality protein? That’s very different from a pet with kidney disease who needs lower protein percentages to ease the stress on the kidneys. Does the pet take medications or supplements? Those can impact nutrient absorption as well! It has a lot of moving parts.Once all of these factors are put together, you and your vet will know the best food choice. But what to feed is only part one. How much to feed is just as important!

   Just like a pound of steak has more calories than a pound of lettuce, knowing how much food to feed depends very much on what food you’ve chosen- which is why “just feed him more!” is less helpful than it sounds. With the right information, nutrition label, and a calculator, your vet has the ability to calculate the exact amount of food right for your pet.

4. Follow up. You’ve got your premium diet chosen; you know how much to feed. Now what? Follow up is key! Your vet will indicate when they want to check in and see how the pet is doing, and assess their weight change. Are they going in the right direction? Once they reach their ideal weight, does the plan change again?

Like so many things in life, how and what to feed your pet is never a simple answer, because our pets change over time, and so do their needs. The good news is, vets have gotten really good at identifying how to pick the right food at the right time.

As Hippocrates once said, “Let food be thy medicine, and medicine be thy food.” Sure, he probably wasn’t thinking of dogs and cats when he wrote that- but it still holds true. Here’s to a long life of health to you and your pets!

If you found this interesting, check out these related stories:

A Guide To Managing Your Dog’s Weight

L-Carnitine And Dog Weight Loss