A lot of dog food is full of allergy triggers — and those bags don’t come with a trigger warning. Humans aren’t the only beings that suffer from adverse reactions to certain foods. In fact, food allergies are the third-most common allergies in dogs, and they can be tricky to spot because the symptoms are not what you think. The most common symptoms are itchy skin, scratching and hair loss. They may also have gastrointestinal issues, such as diarrhea and gas.

Dogs can develop food allergies at any age, and allergies can suddenly be triggered by foods they’ve eaten their entire lives with no issues, making it even trickier to diagnose. Since many symptoms of dog food allergies can also signify other issues, it’s important not to diagnose your pup yourself. If you’ve noticed these issues with your pup, it might be time to switch up his diet. Talk to your vet first, and with their go-ahead, try a limited-ingredient food that avoids some of these main triggers. It may not be possible for you to prevent food allergies in your dog, you can lessen his chances while feeding him a variety of quality, limited-ingredient foods and making sure he has regular checkups with the vet.