How Many Calories Does My Dog Need?
To maintain a dog's weight, energy input needs to balance energy output. In nutrition circles, energy is measured in calories (also called kilocalories or kcal). To prevent unwanted weight gain or weight loss, you need to have a fairly good idea of how many calories your dog needs.
Many factors go into determining a dog's caloric needs. The big ones are:
- Size. Larger bodies need more calories for maintenance.
- Body composition. Muscle burns more calories than fat.
- Age. Puppies need more calories to support growth. A dog's muscle-to-fat ratio tends to shift toward fat with age, which decreases caloric needs.
- Activity level. Exercise can burn a lot of calories.
- Reproductive status. Intact animals generally need more calories than those who have been spayed or neutered. Pregnancy and lactation also require additional calories.
- Metabolism. Some individuals have higher metabolic rates than others.
- Health status. Many diseases (hypothyroidism, for example) and recovery from injury or illness can affect a dog's caloric needs.
- Environment. Dogs require more energy to actively cool or warm themselves.
Calculating your dog's caloric needs
Veterinarians use a couple formulas to determine how many calories pets need. But first, let’s define a few terms:
- Resting Energy Requirement (RER)—the number of calories needed by a typical individual when resting quietly in a comfortable (not too hot and not too cold) environment.
- Maintenance Energy Requirement (MER)—the number of calories needed by a typical individual, also taking into account normal activity plus factors such as as exercise, growth, pregnancy, lactation, etc.
The formula most commonly used to determine a dog's RER is:
RER in kcal/day = 30(body weight in kilograms) + 70
To convert a dog's RER to the more useful MER, you use an appropriate multiplier based on the dog's lifestyle, age, health status, need for weight loss, etc. The multiplier often used for a healthy spayed or neutered adult dog is 1.6 (or 1.8 for intact pets).
Calorie variations and feeding tips
There's no need to immediately start running calculations on your dog, and many online calculators will do this math for you anyway. But however you calculate your dog's number, it's important to remember that it is only an estimate. Your dog's true caloric needs can vary by as much as 25% in either direction due to the variables mentioned above.
Pick a value somewhere within your dog's recommended caloric range that seems reasonable based on everything you know about your pet. Then determine the amount of dog food (and don't forget a few treats!) that adds up to their daily caloric requirement.
Fine tune it based on weight gain or weight loss over time. Talk to your veterinarian if you have any questions or concerns.