Step 0: Support a balanced stress response

When a cat feels stressed or unsafe, their nervous system is focused on coping rather than adapting. In this state, even positive environmental changes can be harder to absorb.

Some families choose optional nutritional support to help support a normal stress response during periods of change.

How supplements may be used

• Daily support: a consistent daily amount to help maintain emotional balance
• Situational support: temporary additional support during predictable stressors (e.g. moving, visitors, renovations, new pets)

BSAVA Principle:

Emotional regulation & readiness for learning

Step 1: Start With Full Separation

Allow both cats to feel safe and regain a sense of control before any exposure occurs.

Excercise

The new cat should have their Exercise: Set Up a Private, Secure Spaceown separate room, fully set up before arrival, including:

• Food and water
• Litter box
• Scratching surface
• Hiding and resting areas
• Vertical space if possible
  

Do not allow face-to-face contact at this stage.

Keep doors closed and prevent visual access.

This step allows:

• the new cat to settle without feeling threatened
• resident cats to adjust without intrusion
• overall stress levels to decrease before introductions begin
  

Time spent here is not lost time — it prevents long-term problems.

BSAVA Principle

Environmental management & territorial security

Step 2: Exchange Scents Before Visual Contact

Allow cats to become familiar with each other safely through scent, without pressure or confrontation.

Exercise: Structured Scent Familiarisation

• Swap bedding, blankets, or toys between cats once daily
• Gently rub a soft cloth on each cat’s cheeks and body and place it in shared areas
• Allow cats to investigate scents at their own pace
• Watch for calm sniffing or neutral responses
  

Do not force investigation.

Calm interest — or even indifference — is progress.

If hissing, avoidance, or agitation appears, slow down and continue with separation.

BSAVA Principle :

Olfactory-based desensitisation

Cats rely heavily on scent to assess safety and familiarity. Positive or neutral scent exposure reduces perceived threat and prepares cats for later stages of introduction.

Step 3: Allow Limited Awareness Without Contact

Introduce awareness of the other cat without triggering fear, pressure, or conflict.

Exercise: Barrier-Based Awareness

• Allow awareness through a closed door, baby gate, screen, or slightly opened door
• Keep sessions brief and calm
• Ensure both cats can retreat freely at all times

Look for:

• calm sniffing
• relaxed posture
• curiosity without staring or hissing

Do not encourage approach or interaction.

If hissing, fixation, or stress appears, return to full separation and continue scent exchange.

BSAVA Principle

Controlled exposure below threshold

Gradual, non-threatening awareness allows cats to process the presence of another cat without escalating fear or defensive behaviour.

Step 4: Brief, Controlled Visual Introductions

Allow cats to see each other calmly while maintaining safety, distance, and choice.

Exercise: Short, Supervised Visual Sessions

• Use brief, planned sessions with a physical barrier (gate, screen) or controlled open space
• Keep distance between cats at all times
• Allow both cats to move away or hide freely
• End sessions while both cats are still calm

Cats do not need to approach, interact, or investigate each other.

End the session immediately if you see:

• hissing
• stiff posture
• intense staring
• attempts to chase
  

Return to earlier steps if needed.

BSAVA Principle

Graded exposure with choice and escape

Allowing visual exposure while preserving distance and retreat options reduces perceived threat and prevents negative associations.

Step 5: Gradually Increase Shared Time (No Interaction Required)

Build tolerance and comfort with shared space while keeping stress low.

Exercise: Calm Co-Presence in Shared Areas

• Gradually increase the length of supervised time cats spend in the same space
• Allow shared access only while both cats remain relaxed
• Maintain multiple escape routes and vertical spaces
• Keep resources separated (litter, food, resting areas)

Cats do not need to:

• play together
• eat together
• interact physically

Calm presence at a distance is already success.

BSAVA Principle

Habituation through repeated calm exposure

Repeated neutral experiences in shared space reduce emotional reactivity and support long-term coexistence.

Step 6: Ongoing Support in multi cat households

Once cats can share space calmly, some households benefit from additional guidance focused on long-term coexistence, resource management, and preventing future tension.

At this stage, refer to:

“Multi-cat household Protocol”

for ongoing support and practical strategies.

Step 7: When to Seek Additional Help

While many multi-cat households improve with consistent management and time, some situations require professional support.

Please consult your veterinarian if

• Aggression escalates: biting, repeated attacks, or injuries occur
• One cat withdraws: increased hiding, fear, or reduced interaction persists
• Litter box problems develop: changes appear despite proper setup
• Progress stalls: tension remains despite consistent application of the steps
• Safety feels uncertain: at any point for people or cats
  

Some cases benefit from medical assessment or referral to a qualified behavior professional.

BSAVA principle: Medical rule-out & appropriate referral — persistent or escalating behavioral issues should be assessed for underlying medical or behavioral causes to ensure appropriate support.