My cat is continuously pacing, biting and scratching, has dilated pupils and appears anxious and restless—what could be causing this and how should I manage it?

Acute Behavioral Crisis in Cats: Differential Diagnosis and Management

Your cat is likely experiencing either acute pain, severe stress/distress, or a medical emergency requiring immediate veterinary evaluation—this constellation of symptoms (pacing, biting, scratching, dilated pupils, restlessness) demands urgent assessment to rule out pain, neurological conditions, or systemic illness before attributing it to purely behavioral causes.

Immediate Assessment Priorities

Medical Emergencies to Exclude First

The combination of dilated pupils, pacing, and agitation in cats can indicate:

• Acute pain from trauma, urinary obstruction, or internal injury 1, 2
• Neurological conditions including neuropathic pain or central nervous system disorders 3
• Systemic illness causing distress and behavioral changes 1

Critical point: Cats do not express pain in easily recognizable ways, and simple cage observation is often inaccurate for pain assessment 4. The behaviors you describe—particularly the biting, scratching, and restlessness—are consistent with acute pain behaviors validated in feline pain research 2.

Key Clinical Signs Suggesting Pain vs. Pure Behavioral Distress

Look for these specific indicators 2:

• Crouched/hunched posture when briefly still
• Attention to a specific body area (wound site, abdomen, urinary tract)
• Abnormal gait if the cat moves
• Eye squinting or blepharospasm beyond just dilated pupils
• Head position (lowered head suggests pain)
• Depressed affect alternating with agitation

Structured Diagnostic Approach

Step 1: Rule Out Life-Threatening Conditions

Immediate veterinary examination should assess 1:

• Urinary obstruction (male cats especially—palpate bladder, check for straining)
• Trauma or bite wounds (check entire body, including between toes and under tail)
• Abdominal pain (pancreatitis, foreign body, intestinal obstruction)
• Neurological deficits beyond behavioral changes

Step 2: Assess Pain Likelihood

If any of these 13 validated pain behaviors are present, assume pain until proven otherwise 2:

• Positioned in back of cage/hiding
• No attention to surroundings
• Feigned sleep
• Abnormal grooming (excessive or absent)
• Attention to wound/body area
• Crouched/hunched posture
• Abnormal gait
• Depressed affect
• Difficulty grasping food
• Head shaking
• Eye squinting/blepharospasm
• Lowered head position

Step 3: Consider Stress-Related Causes Only After Medical Exclusion

Territorial security threats are the most common cause of behavioral distress in cats, as they rely more on territorial security than social attachments 5. However, this diagnosis requires ruling out medical causes first 1.

Stress-associated behavioral changes include 1:

• Perceived threats from other cats (indoor or outdoor)
• Environmental changes
• Inadequate socialization during development
• Strongly aversive recent events

Critical caveat: Medical and behavioral conditions almost always contribute concurrently to clinical signs in cats—they are not mutually exclusive 1.

Management Algorithm

If Pain is Suspected or Cannot Be Ruled Out

Preemptive pain management is more effective than treating established pain 4:

1. Opioids for moderate to severe pain (buprenorphine is well-tolerated in cats) 4
2. NSAIDs if appropriate for the condition (with caution regarding renal function) 4
3. Multimodal approach for neuropathic pain if suspected: combine analgesics with adjuvant drugs 3
4. Local/regional anesthesia for localized pain sources 4

If Purely Behavioral After Medical Clearance

Address territorial security 5:

• Identify and remove threats (other cats, environmental changes)
• Provide secure hiding spaces
• Consider pheromone therapy
• Gradual environmental modification

Common Pitfalls to Avoid

• Never assume behavioral causes without medical workup 1—the interplay between physical and emotional health is profound in cats
• Do not rely on obvious pain expression 4—cats mask pain effectively
• Avoid attributing dilated pupils solely to fear 2—this can indicate pain or neurological issues
• Do not delay treatment while observing 4—preemptive pain management is superior

Bottom Line for Immediate Action

Take your cat to a veterinarian immediately. The symptom cluster you describe has too much overlap with serious medical conditions (particularly pain and urinary obstruction) to manage at home 1, 2. Even if the ultimate diagnosis is behavioral, ruling out medical causes is essential for your cat's welfare and will guide appropriate treatment 1.