Answer-first
What should I know before bringing home a second cat?
Two things decide success: resources and pace. Set up separated resources first (litter boxes = cats + 1, spread-out food/water/resting spots), then run a slow, scent-first introduction over days to weeks — never a face-to-face on day one.Fact
A rushed introduction is the single most common cause of lasting cat conflict. Prepare the home before the cat arrives.
Applies to: People adding a second (or another) cat to the home. Preparation + introduction page.
Steps
Prep the home first (before arrival)Fact
- Litter boxes: one per cat plus one (n+1), in separate locations
- Duplicate and spread food, water, resting, and hiding spots so nothing must be shared or guarded
- A separate 'base camp' room for the newcomer with its own everything
Introduce slowly (scent first)Fact
- Keep the cats separated at first; swap scents (bedding, gentle stroking) before any sight
- Feed on opposite sides of a closed door to build positive associations
- Progress to visual contact (cracked door/barrier), then brief supervised together-time — at the more nervous cat's pace
- Setbacks mean slow down, not push
Pick a fit that helpsProfessional guidance
- Match energy where you can; some adults settle faster than a boisterous kitten for a mellow resident
- Never force interaction; hissing early is normal communication, sustained fighting is not
- Budget weeks, not days
Normal vs keep-watching
Normal: Cautious curiosity, some hissing, and gradual coexistence over days to weeks with a slow introduction.
Keep watching: Each cat's stress signs, resource guarding, and whether progress or setbacks are happening.
When to contact a vet. Injuries from fighting, or a resident cat that stops eating or using the litter box during the introduction, is a vet matter (rule out stress-related illness) — this page never diagnoses; persistent conflict after a proper introduction warrants a behavior professional.
What changes this answer
- Resident cat's temperament (match the newcomer)
- Kitten vs adult newcomer (energy fit)
- Home size (more separation needed in small spaces)
Common mistakes
- Face-to-face on arrival
- Sharing resources to save space
- Rushing when there's hissing
- No separate base-camp room
Sources
- AAFP / American Association of Feline Practitioners (T1) — accompanies 2024 AAFP Intercat Tension Guidelines (JFMS) · Tier 2 · verified 2026-07-17 · commercial bias noted · source conflict noted
- Ohio State University Indoor Pet Initiative (T2 academic-veterinary); corroborated by AAFP (catvets intercat guide) and AAHA/AAFP Life Stage Guidelines · Tier 2 · verified 2026-07-17 · commercial bias noted · source conflict noted
- T4 (ASPCA — established US animal-welfare authority) · Tier 3 · verified 2026-07-17 · commercial bias noted · source conflict noted
Real questions cat owners ask
- How do I introduce a second cat?
- How long does it take cats to get along?
- Will my cat be jealous of a new cat?
Set your (new) cat count in your Passport profile — the litter and resource tools recompute n+1 for you. Set up your Cat Passport.