The short verdict for a Boxer and a cat household
Many Boxers do settle happily alongside cats, and plenty spend their lives snoozing within a few feet of a feline housemate without incident. The honest caveat is energy and style, not malice. A Boxer is a large, physical, mouthy player who bounces, paws, and charges in for fun, and that approach can overwhelm a cat even when the dog means no harm at all. A confident, dog-savvy cat who holds ground often does far better here than a shy cat who bolts, because running is the one response most likely to switch on a Boxer's chase instinct.
Breed alone does not settle the question. A Boxer raised from puppyhood with cats usually reads their signals well and treats them as family. An adult Boxer with no cat history, or a rescue whose background is unknown, needs a careful test period before anyone assumes the pairing is safe.
Why some Boxers chase and others do not
Boxers were developed as working dogs with a strong prey drive underneath the clownish exterior. Movement triggers it: a cat darting down a hallway, fleeing across a yard, or scrambling up furniture looks, to an aroused Boxer, like an invitation to pursue. Inside a calm room, the same dog may sniff a still cat politely and wander off, so judge him around a cat that moves and occasionally runs, not from one quiet meeting.
Temperament varies by line and by individual as well. Some Boxers are soft-mouthed and easily redirected the moment you call their name. Others fixate, go quiet and still, and stop responding to cues they know perfectly well in other settings. That fixed stare, a stiff body, and an inability to look away when the cat moves are the signals that this particular dog needs far more management, or a cat-free home.
Testing the pairing before you decide
If you are meeting a Boxer you hope to adopt, ask directly what is known about cats, then set up introductions in stages rather than one free encounter. Begin with scent: swap bedding between the dog and the cat for a few days so each animal learns the other's smell without pressure. Next, let them see each other through a sturdy baby gate or a cracked door secured so neither can push through, rewarding the Boxer for looking at the cat and then turning back to you.
Only when the dog can watch calmly, take treats, and respond to his name at the barrier should you try a leashed meeting in a room where the cat has clear escape routes and high places to climb. Keep the leash loose, keep sessions short, and end while things are still boring. Repeat over several days. A dog who improves session by session is showing you he can learn the house rules; a dog who escalates needs a professional trainer's assessment before you proceed.
Setting up a home that keeps both animals safe
Management is what makes a good pairing last. Feed the animals separately, keep litter boxes somewhere the Boxer cannot reach — dogs are notorious litter-box raiders, and a cat cornered there feels trapped — and make sure the cat always has at least one room the dog cannot enter. Supervise all shared time for the first weeks, and crate or separate the Boxer when you leave until you have a long, dull record of coexistence.
Teach and heavily reward a solid leave-it and an emergency recall using games that do not involve the cat. If chasing starts, interrupt cheerfully, separate the animals calmly, and step back in the plan rather than scolding an instinct you can redirect but not punish away.
When the match works, help the history travel with the dog himself: KinsLe Transferrable Profiles moves a Boxer's known cat experience, feeding routine, and training progress to his new owner intact, so the careful introduction work you started is continued, not restarted.