Answer-first
One of my cats is bullying the other — what do I do?
Bullying is usually a resource-and-space problem wearing a personality mask — and if it appeared suddenly, rule out pain or illness in either cat first. Then remove the competition: more separated resources (litter, food, water, high perches) so no cat can be blocked or cornered.Professional guidance
Medical-first for sudden changes, then resource redistribution. Punishing the 'bully' raises stress and backfires.
Applies to: Homes where one cat chases, blocks, ambushes, or guards resources from another. Behavior + safety page, medical-first for sudden onset.
Steps
Rule out the body (if it's new)Fact
- A sudden shift to bullying can be pain or illness in the aggressor OR the target — vet check first
- Any notable behavior change warrants a medical rule-out (ASPCA)
Kill the competitionFact
- Litter boxes n+1 in SEPARATE locations so none can be guarded
- Multiple food/water stations spread apart; feed apart if one blocks the other
- Add vertical space and hiding spots so the target always has an escape route and a high retreat
Manage, don't punishProfessional guidance
- Never punish the bully — it adds stress and worsens things
- Interrupt chases with a noise/toy redirect, not your hands
- If it's severe, separate and reintroduce gradually (as for new cats); persistent bullying after good setup = a behavior professional
Normal vs keep-watching
Normal: Minor squabbles and occasional chasing are normal; relentless blocking, ambushing, injuries, or a target that hides constantly is not.
Keep watching: Which resources get guarded, escape routes available, whether the target is eating/eliminating normally, and any injuries.
When to contact a vet. A target cat that stops eating or using the litter box, or any injury from bullying, needs a vet (stress-related illness and bite wounds are real); sudden onset needs a medical rule-out in both cats. This page never diagnoses.
What changes this answer
- Sudden vs long-standing (sudden = medical-first)
- Resource layout (the usual root cause)
- Home verticality (escape routes)
Common mistakes
- Punishing the aggressor
- Too few, clustered resources
- No high escape routes for the target
- Assuming it's just personality when it's competition
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
- ASPCA (T2/T4 behavior) + AAFP/ISFM Environmental Needs Guidelines (T1, PMC11383066) · 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
Real questions cat owners ask
- Why is my cat bullying my other cat?
- How do I stop one cat picking on another?
- Is my cat bullying or playing?
Set your cat count in your Passport profile so the resource tools compute enough separated boxes and stations. Set up your Cat Passport.