Find out if you and your pet are prepared for a new family member.

For most pet owners, it’s easy to imagine bringing home a second pet. After all, think how cute your little guys would look posing in a family photo together. Your pet might be totally psyched too—or not. Before you buy matching outfits for that photo shoot, here are some factors to consider when adding a new dog or new cat into the mix.

Adding a Second Dog

For dog folks, a second pet is often inspired by worries that being an “only pet” is lonely. But a second pet will only cheer your dog up if what they’re craving is a pal, not more of your attention. Dogs don’t see us humans, as buddies—to them, we’re basically their parents. So if they’re not getting enough time with you as it is, another pet could mean fewer one-on-one hangouts and jealousy. But if your dog was voted Most Popular at the dog park, then it’s full-speed ahead. They’re clearly into four-legged friendships and we all know from the internet how awesome those can be.

Another thing to consider is your pet’s behavioral issues. Dogs tend to mimic the behaviors of their fellow animals, so if one pet is acting out, you might end up with double the trouble. On the flip side, if your pet is already an obedience school superstar, that could be a perfect reason to get a puppy, as they go through training much quicker with an older dog to guide them.

Feeling confident your dog will be into a new addition? Time to start matchmaking. It’s important for dogs to have things in common, but they don’t necessarily have to be the same breed (did you know dogs can actually identify different breeds as dogs, even if they look nothing like them?). The two biggies are activity and health levels. They’re going to be playing together all day so you want them both to be able to keep up. What about size? Generally, being close in size is good, but maybe not too close. A small dog or even a new puppy can be a good pal to an older big dog, but it might not work as well with a young large breed who plays rough. Lastly, choosing a dog of the opposite sex of your current pup may be your best option. Dogs of the same sex can still become best friends, but it may be more of a challenge to get there.

Getting Your Cat a Feline Friend

Are any cat people looking to become a two-litterbox household? Adult cats tend to have a no new friends policy, but don’t give up. It turns out even they can’t resist a new kitten. If you’re still considering getting another adult cat, just remember that opposites attract—same sex cats tend to fight more. And don’t forget interspecies buddies. According to one study, over 66% of cats and dogs were able to learn to live together peacefully because they were introduced when they were both super young.

At the end of the day, it all comes down to chemistry and an introduction process. If you can, give the two animals a chance to meet first outside of the home and see what their vibe is like, and watch their body language. Taking your dog and your new friend on a walk is a good way to get to know each other (and look for any signs of tension in a controlled way). Hopefully, you’ll all end up one big family (but maybe without the matching outfits).