Need to Switch Your Pet's Food? Here Are Key Steps to Take

Your veterinarian has recommended a diet change for your pet. Easy, right? Maybe not. It may seem daunting, but here are a few steps you can take to successfully switch over to a new food or way of feeding.

1. Go Slow

Any two diets will have differences between them — even if these differences are subtle. These differences are probably why your veterinarian recommended the diet change in the first place. This change may affect your pet’s response to the new diet, as well as the response of his or her digestive system. Just like people, the digestive systems of pets contain a number of normal intestinal bacteria that help with the digestive process. When a diet change is made, your pet’s system is receiving a new formulation of nutrients that could cause a shift in the numbers and types of beneficial intestinal bacteria. These shifts are usually subtle but may be noticeable if they happen quickly. For example, a new diet that is higher in fat or has a different amount of dietary fiber could contribute to soft stools or gas if the change is not made slowly. This doesn’t mean the diet won’t work, only that a more gradual change may be needed to allow the bacteria time to adjust. For this reason, diet changes should usually be made over a period of at least a week. And if your pet vomits, has persistent diarrhea or gas, refuses to eat or seems lethargic, call your veterinarian.

2. Choose the Right Time and Place

Pets rely heavily on their sense of smell and connect the scent of a diet with how they feel when they smell the food. For that reason, sick pets may associate feeling poorly with the diet offered at the time, causing a food aversion (reluctance or refusal to eat the food). If this happens, the pet may be unlikely to eat that diet later. For this reason, it’s best to make diet changes once pets are discharged from the hospital and feeling better. If a diet change absolutely has to be made before your pet has recovered, check with your veterinarian on how to achieve this for long-term success.

How, when and where your pet is fed can also affect your pet’s willingness to eat a new diet. It is best to feed your pet in a quiet area without other pets around so that he or she will not be distracted or feel the need to compete for food. If pets need to be fed different diets, it's best to keep them separated during meal times.

3. Strategize

Diet change works better as a deliberate process. Several strategies can be effective.

Some pets need time to accept a new diet as “not new anymore” before they try it. At mealtime, offer the new and the old diets in separate bowls. When meals are done, throw out the uneaten portion of the new diet. This seems wasteful, but it’s important. The food’s smell and texture changes as it is exposed to air, so offering fresh food at each meal is more attractive than offering leftovers. After a week, gradually decrease the amount of the old diet and increase the amount of the new diet, until your pet is fully transitioned to the new diet. You may also make the new diet more attractive by adding a bit of something extra-tasty — although check with your veterinarian first before adding anything to make sure it is safe for your pet and whatever his or her medical condition is. Once the transition is done, decrease the amount of the extra item until it is eliminated.

Another strategy is mixing the two diets together, starting with 90 percent of the old diet and 10 percent of the new diet, with a gradual shift in proportions each day until your pet is fully transitioned to the new diet. Again, adding a bit of something extra-tasty (check with your veterinarian) may make the transition easier. This item can be withdrawn gradually once the transition is complete.

4. Monitor Your Pet’s Weight

Your veterinarian should let you know how much of the new diet your pet should be eating each day and whether he or she should stay at the same weight, gain or lose weight. If weight gain or loss is the plan, guidelines for how much your pet’s weight should change per week or month and how to adjust the amount to feed each day to achieve these goals, are also needed. Sometimes pets eat less during the diet transition, which is usually not cause for alarm. If you notice this, discuss it with your veterinarian and be able to describe how much of each diet your pet is actually eating. This helps your veterinarian to decide if changes to your pet’s feeding plan need to be made.

5. Prepare yourself

Now you’ve seen that making a diet change isn’t necessarily simple. To help make it successful, make a plan. Decide how you will monitor your pet’s intake of the new diet, how much of the new diet you will need to purchase at a time, where you will purchase the new diet (some therapeutic diets are available only through veterinary hospitals or with a prescription) and when you will have to re-order it. Also, think about how feeding will change for your other pets. Free-feeding is common in multi-pet households, so changing one pet’s diet generally means that either all pets will change or that pets can’t be allowed to eat each other’s food.

Keep in mind that the change is important for your pet’s health, so continuing to feed your pets’ old diet may not be recommended.

If you foresee or have difficulties with making a diet change, such as a pet who absolutely refuses to eat the new diet, discuss your concerns with your veterinarian.