3 Steps for Determining How Many Calories Your Cat Needs

By PetMD Editorial on Jan. 15, 2015
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How Many Calories Does Your Pet Need?

In order to properly determine how many calories your pet needs, his or her lifestyle, age, activity level, and many other factors must first be considered. How do these factors affect your cat and how should you go about determining your pet's caloric needs? Let's take a look.

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1. Ask Your Vet

Including your veterinarian in any conversation dealing with your pet's dietary and caloric needs is vital, particularly if your dog has any health problems or special dietary needs. "Nutrition, including determining how many calories a pet should be taking in, is not a one-size-fits-all endeavor," says Jennifer Coates, DVM. This is exactly why you need the expertise of your veterinarian. Calorie “calculators” or tables cannot take into account what might make an animal’s situation unique.

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2. Whip Out the Calculator

The standard steps used by veterinarians to determine a pet’s caloric needs (otherwise known as their maintenance energy requirements) are as follows:

  1. Divide a cat’s body weight in pounds by 2.2 to convert to kilograms (kg)
  2. Resting Energy Requirement (RER) = 70 (body weight in kg) 0.75
  3. Maintenance Energy Requirement (MER) = appropriate multiplier x RER

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3. Factor in an 'Appropriate Multiplier'

Appropriate multipliers include such things as whether or not the cat is neutered or intact, whether the cat requires weight gain or weight loss, and a variety of other factors. For example, to estimate the RER or resting energy requirements, for an adult neutered cat you use the following formula RER = 70 x (ideal weight in kilograms) 3/4. You then multiply this times 1.2, which is the appropriate multiplier for a neutered cat. However, this calorie count should only be viewed as an estimate. Your veterinarian will use this information as a piece of the puzzle; also taking into account a pet’s lifestyle, age, activity level, etc.

Watch Out for Low Quality Cat Food

Remember to do a nutrition comparison. Some pet food brands require more calories to be fed to the pet in order to achieve the same nutritional benefits a higher quality pet food can achieve with less. This is due to the difference in nutrient content. Consult your veterinarian on how to determine if this may be affecting your pet.