This article was created in partnership with Instinct as part of A Better Way.

If you’re like us, your pets are your children—full-fledged members of the family with their own personalities, food preferences, toys, and clothes (no judgment). And guess what? You’re not alone. According to a 2016 Nielsen report, 85 percent of pet parents “believe they can extend the lives of their pets based on the foods they feed them,” and—get your gasps ready—the majority of pet owners would be willing to sacrifice personal luxuries like chocolate or Netflix if that meant feeding their pets a healthier diet.

So we’re all cool with splurging on top-quality chow (U.S. pet owners spent a staggering $29 billion on pet food in 2017), but does spending more mean we’re buying the best food? And do we even know what we’re feeding them?

We’re partnering with the folks at Instinct to demystify pet food and help you shop smarter. They make natural, minimally processed, raw pet food using cold-pressure technology to preserve vitamins, minerals, and other nutrients. Because Instinct cares just as much about your pet’s nutrition as you do, we went straight to the experts to uncover the four not-so-great ingredients that might be sneaking into your pet’s bowl.

1. Undefined Animal By-products

A broad term covering a lot of different ingredients, animal by-products are often used as a source of protein in pet food. They’re also perhaps the most controversial. Animal by-products are defined as “parts of animals or products of animal origin… not intended for human consumption,” which (look away if you’re squeamish) can include anything from tissue and fat to feet and bones.

Animal by-products are not necessarily bad in and of themselves—organ meats, for example, can be a rich source of protein and nutrients. But pet food companies don’t have to specify the type of meat or the parts being used and often just list them generically as “meat meal” or “meat by-product meal.”

Vet nutritionist Andi Brown refers to it as the Four Ds: “In our research, what we found is that companies are allowed to use what’s called four-D meats, and that is animals that arrive at the slaughterhouse dead, diseased, dying, or disabled,” Brown says. “Anything that was rejected for humans to eat was going to pet food plants [and then] bombarded… with a number of chemical agents and preservatives and dyes.”

Instead, look for labels that say exactly what type of meat is being used (e.g., “turkey” or “turkey meal” instead of “poultry meal” or “meat meal”) and do your homework.

Instinct, for example, uses only real ingredients, like high-quality, single-protein-source meats and meals. It also doesn’t cook its ingredients to death or add chemical preservatives. Instead, the brand uses high-pressure processing to keep nutrients intact and provide a safe, raw option for pets.

2. Artificial Coloring/Food Dyes

One of the most common additives found in commercial pet food and treats is artificial coloring. “A lot of times someone buying pet food sees the packaging and the colors and thinks it’s OK for dogs to eat,” Patrick Mahaney, VMD, a holistic veterinarian says. “It’s confusing as a consumer, [but] the dog doesn’t care about the color of the food—it’s the taste that matters.”

For example, that caramel color in your pet’s food may contain something called imidazole, also known as 4-MIE. “That is a known cancer-causing agent and not something that your pet should be consuming,” Mahaney says.

So why is it in pet food in the first place? For one, dog food doesn’t have to pass the same regulatory standards as people food. But even the use of FDA-approved color additives is controversial—many people worry about the potential cancer-causing effects of eating dye. While more research is needed, it’s not a bad idea to steer clear of artificial coloring when possible.

3. Corn, Corn Gluten, and Cornmeal

While research has shown dogs have adapted to a starch-rich diet thanks to human domestication over the last 11,000 years, the nutritional benefit of corn for pets is widely debated. Some vets believe corn is a perfectly healthy protein source; others have linked it to pet allergies and digestion trouble.

“Corn is actually the No. 1 ingredient found in common pet foods today, but it’s difficult for pets to digest,” Brown says. “So just because something is human grade or natural does not mean that it’s the best choice for your pet.”

4. BHA and BHT

If you’ve ever wondered how your pet’s food stays fresh, it isn’t by happenstance. According to the National Institute of Health, BHA (butylated hydroxyanisole) is a known chemical preservative in pet food that has been found to consistently produce certain types of cancers in animals. BHT (butylated hydroxytoluene), a form of carcinogen that causes kidney and liver damage, is also used to help preserve food longer.

“Anything with a number or letters attached to it when it comes to dry food you want to avoid,” Mahaney says.

Gross! So what now?

If you’re feeling a little freaked out, it’s important to remember there are plenty of brands without these less-than-stellar ingredients. Read labels and look for a high-quality pet food with minimal processing and no mystery ingredients.