If you've ever stepped up your exercise game to train for a race or amped up your time at the gym, you're probably familiar with the hunger pangs that go hand-in-hand with increased exercise. Your pet's digestive system functions in a similar way: if he's getting more exercise than usual, he needs more food and water to maintain a healthy weight. Except, unlike you, your dog can't just raid the fridge for a healthy afternoon snack.
Determining how much to feed your pet comes down to her body type, her activity level, and whether she needs to gain, lose or maintain weight. Here's help figuring out how much food and water an active pet needs.
Related: Is My Pet Getting Enough Exercise?
Your veterinarian is the best person to determine your pet's ideal weight and food/water intake, but you can do a general assessment at home. Look at your pet and feel her ribs. You want to be able to feel the ribs easily and see a bit of a defined waist—but if her ribs are jutting out or her waist isn't defined at all, she may be a little over- or underweight. The Body Condition System, developed at the Nestlé-Purina PetCare Center, gives you good visuals and descriptions to go on and is based on a nine-point system.
"Each point on the nine-point body condition score represents a 10-15 percent change of body mass," says Jonathan Stockman, D.V.M., D.A.C.V.N., a veterinary nutritionist at Colorado State University's Veterinary Teaching Hospital. While interactive charts are readily available online for use as an at-home guide, consulting your vet is the best place to start when considering diet or activity changes. Your veterinarian can help you set nutrition goals for your pet's individual needs, and help you decide how best to achieve those goals.
There are general guidelines for humans around physical activity. Most adults should be aiming for 150 minutes per week of moderate activity per week plus two full-body strength training sessions. There aren't the same guidelines to determine appropriate activity levels for a dog or cat, Stockman says.
"In general, though, working dogs or sporting dogs that do hunting or search-and-rescue are considered high-activity dogs, whereas pets—even if they play a lot—typically don't engage in the same levels of activity," Stockman says. "Most pets are fairly sedentary." Which makes sense if you think about how much lounging about your house your dog or cat is probably doing during the day.
However, if you do own a sporting or working dog, he may require a specialized diet depending on whether he engages in higher-intensity sprinting activities, or longer, more moderate aerobic activity lasting longer than 30 minutes.
"Dogs who are very active and primarily engage in short, intense bursts of activity may need additional carbohydrates and protein to maintain appropriate muscle mass," Stockman says. "Dogs who typically engage in exercise that's over 30 minutes in duration but at a more moderate pace may benefit from a diet higher in fat."
As a general rule, a dog that increases his activity level will require more food and water. The best way to gauge this is to keep an eye on your pet's body index; if he or she seems to be gaining or losing weight with changes in his/her diet and activity level, you may need to adjust what you're feeding.
On a hot day, your pet will tell you if he's overheated by panting more than usual. If it's hot and dry weather, your pet runs a higher risk of dehydration or heatstroke, and needs additional water.
Be sure to offer your pet fresh free-choice water at all times. Your pet may need some encouragement to drink enough water; be aware that some pets may also become accustomed to the taste of your water at home, and may be less likely to drink on the road or away from home. If that's true for your pet, pack extra water on trips and use it to gradually accustom your pet to different-tasting water at your destination.
And don't offer an overheated or fatigued pet a sports drink, says Stockman. "There's no evidence that sports drinks help dehydrated pets recover—and such drinks may actually be counterproductive, as dogs don't sweat like we do; most of their water loss occurs through panting, not by sweating out electrolytes as humans do. Instead, make sure your pet has access to water, and try to avoid situations where your pet could overheat."
While the exact quantities of food and water for an active pet may change over time, you can help your pet maintain a healthy weight by keeping an eye out for any changes in body mass or routine. And unless your dog falls into the working-dog category, he or she would likely benefit from as much daily activity as you have time to provide. What's good for your dog is also good for you, extra walks and runs will help you meet your activity goals for the week too.