How do I introduce a new pet to my current pet?

Slow. The single biggest mistake is rushing.

Cats meeting cats — 7 to 14 days:
- Day 1–3: separate rooms, no visual contact. Swap blankets daily so each cat smells the other on neutral surfaces
- Day 4–6: feed them on opposite sides of a closed door, gradually moving bowls closer
- Day 7–10: brief visual contact through a baby gate or cracked door
- Day 10–14: short supervised meetings, ending before tension builds

Cats meeting dogs:
- Same isolation period
- Dog must be on a leash for first introductions — for weeks if needed
- The cat must always have an escape route (high shelf, cat tree)
- Reward the dog for calm behaviour around the cat; never let the dog chase

Dogs meeting dogs:
- First meeting on neutral ground, not at home (a park, a quiet street)
- Both on loose leashes — tense leashes communicate tension
- Walk side by side, then let them sniff briefly, then continue walking
- Bring them home together, both leashed, supervise for the first few hours

Universal rules:
- Keep the resident pet's routine as unchanged as possible — same feeding times, same walks
- Give the new pet their OWN safe space (a room, a crate)
- Don't punish growls or hisses — they're communication, not aggression. Removing the warning often leads to bigger reactions
- If after 2–3 weeks you're seeing real aggression, get a behaviourist — don't push through

Most introductions succeed. The pets just need time to negotiate the new dynamic without you forcing the timeline.