Many dogs act like they have a “cast-iron stomach”; eating objects and substances that make us wonder what they were thinking. And while it’s true that dogs can sometimes consume these things with no apparent ill effects, it’s also true that a sudden change of a dog’s primary diet can be hard on them. Changing the main ingredient of your dog’s diet should be done gradually.

How gradual is gradual?

We recommend switching to a new food over the course of 7-10 days. Make a mixture that contains 25% of the new food and 75% of the old food and feed that for two to three days. Then make it 50-50 for two or three more days, then 75% new food and 25% old food for another couple of days. If your pet seems comfortable with this progression, you can start feeding 100% new food.

What happens if you don’t do it gradually?

If you feed too much of the new food too soon, your pet could suffer from stomach upset or cramps, heartburn, indigestion, vomiting, excess gas, constipation, or diarrhea. They may simply refuse to eat a new food that has been introduced suddenly. Intestinal bacteria play an important role. Normal bacteria in the intestine help your dog digest food. A sudden change in food can result in changes to the number and type of bacteria and their ability to help digest food. These changes can lead to intestinal upset.

Some dog Guardians have developed the habit of having an array of dry dog food choices, or of buying whatever is on sale that week to the feed the dog and save some money. It may save you a few dollars in the short term, and it may be convenient for you, but you are hurting your dog. Chronic indigestion, finicky eating habits, and chronic diarrhea are just three common things that will happen if you like to switch your dog’s foods constantly.