Your cats' experience decides the standard
Your resident cats were there first, and a bad match costs them their home territory, their confidence, and possibly their safety. So assess candidates by the standard of a cat who must share hallways, doorways, and quiet corners with this dog every day — not by whether the dog can survive a supervised five minutes in a meet-and-greet room. The right dog makes your cats' lives only mildly more interesting; the wrong one reorganises the house around fear.
Bring information with you: your cats' ages, confidence, health, and escape routes, whether they have lived with a dog before, and how they react to visiting dogs. A rescue that knows your cats' picture can steer you away from candidates you should never meet.
The body language to look for at the rescue
Watch what the dog does with his whole body when he notices a cat, ideally at a distance first and through a barrier. The promising picture is soft and brief: ears and posture relaxed, a glance at the cat, then attention returning easily to you or to sniffing the ground. A dog who can look away from a cat can learn to live with one.
The warning picture is intensity. Hard, fixed staring, a body that goes still and forward, stalking steps, trembling with excitement, whining or barking in frustration, and snapping at the barrier all signal prey drive or arousal that management alone may not make safe. Movement is the true test: many dogs ignore a sleeping cat and ignite when the cat runs, so ask whether the dog has been seen around a moving cat, and treat a chase response as a decisive answer, not a training project.
History beats hope
Ask the rescue for evidence, not impressions. Has this dog lived in a foster home with cats, and what exactly did the foster observe over weeks — sleeping in the same room, chasing in the garden, guarding food from the cat? Was he surrendered for harming or obsessing over cats in a previous home? Shelter kennel behaviour around cats is a weak guide because stress suppresses some dogs and inflames others, so weight foster and previous-home records most heavily.
Adult dogs with a known, calm cat history are usually safer choices than puppies for this particular job. A puppy grows into his breed's prey drive over the first two years, whereas a settled adult who has already lived peaceably with cats has shown you the finished behaviour. Be extra cautious with breeds and types selected for chasing and catching small animals, however friendly the individual seems in a quiet room.
Test fairly, then introduce slowly at home
Meet more than one candidate if you can, and do not let a dog's charm in other respects talk you past a fixed stare. Where the rescue allows it, a second meeting on a different day tells you whether calm behaviour is consistent or was exhaustion.
At home, plan a staged introduction regardless of how good the meeting looked: scent swapping first, the dog on a lead with barriers between animals, cats free to leave every encounter, feeding and resting areas separated, and no unsupervised access for weeks. Your cats should gain confidence steadily; retreating, hiding, or refusing rooms means slow down, not push on.
Keeping the rescue's observations in your file
The notes that justified your choice — foster reports of this dog living with cats, staff observations, any cautions about movement or feeding — should not stay behind at the rescue desk. KinsLe helps them come home with the dog through Transferrable Profiles, so what the rescue learned about him stays attached to his profile for everyone who cares for him.