The test is what they choose, not what they endure
A dog and cat can share a house for years by carefully avoiding each other, which looks peaceful on a quick glance. Getting along is different: both animals choose proximity when nothing forces it, move freely through shared rooms, and relax deeply enough to sleep in the open. Ask whether each pet's world has grown or shrunk since they met — a cat that once used the whole house and now lives on top of the wardrobe is tolerating, at best.
What genuine ease looks like day to day
Look for loose, wiggly greetings or calm indifference as they pass, a cat rubbing against the dog or choosing a chair in the same room, and a dog that glances at the cat then looks away and settles. Play, when it happens, is mutual and interruptible, with the cat free to leave at any moment and choosing to come back. Both animals eat with normal appetite, use their usual resting places, and show their full range of behaviour — the cat still plays and explores, the dog still relaxes with an exposed belly.
What mere tolerance looks like instead
Tolerance is full of quiet compromises: the cat travels by countertop and door-top to avoid floor level, waits until the dog is out to eat or use the litter tray, or has retreated to a single safe room. On the dog's side, watch for hard staring at the cat, freezing when the cat moves, whining fixation at closed doors, and explosive lunging at sudden movement even if contact never happens. A house can be silent and still stressful — absence of fights is not the same as presence of ease.
Check the pressure points around the house
Behaviour at resources tells the truth faster than behaviour on the sofa. Notice who controls doorways, stairs and the route to the litter tray, food and garden; a cat that hesitates, sprints or toilets elsewhere is navigating around the dog, not living alongside it. Evenings are revealing too, since animals that cope all day often show the strain at close quarters when the household settles in one room. Note which animal always yields, and whether the yielder's behaviour, grooming or appetite has changed.
Help a tolerating pair become an easier pair
Do not force friendship with held introductions or shared treats at close range, which raise pressure on both sides. Instead add what tolerance lacks: extra high routes and resting spots for the cat, a litter tray the dog cannot reach, feeding stations fully apart, and daily one-to-one time for each animal. Reward your dog for calm looking-away from the cat and keep a lead or gate in place during exciting household moments until relaxation is consistent, not occasional.
When to get professional help promptly
Any chase that ends in contact, a dog that has pinned or mouthed the cat, wounds of any kind, or a cat that stops eating or hides for a full day moves this beyond home management. Separate the animals completely and speak to your vet, who can rule out pain driving irritability and refer you to a qualified behaviourist. The same applies if the dog's fixation is intensifying week by week despite careful management — predatory focus on a cat is a safety issue, not a personality quirk.
Build the picture from everyone's observations
One person sees the peaceful mornings; someone else sees the cat sprinting the hallway at night. KinsLe Family Sharing lets the household pool those observations against each pet's shared details, so the family judges the relationship from the whole pattern rather than whoever happened to be in the room.