SUDDEN CHANGE IN PERSONALITY OR DEMEANOR
WHAT THIS SYMPTOM USUALLY MEANS
Sudden personality change—becoming irritable, fearful, withdrawn, or overly attached—
almost always indicates a medical cause.
MOST COMMON CAUSES
MILD
• Environmental stress
• Conflict with another pet
MEDICAL
• Pain
• Cognitive dysfunction
• Thyroid disease
• Vision or hearing loss
• Hypertension
• Anxiety disorder
• Neurological disease
EMERGENCY
• Personality change + seizures
• Change + collapse
• Change + sudden blindness
RED FLAGS
• Sudden onset in seniors
• Personality change + pacing
• Personality change + vocalizing
If you’re unsure, treat it as urgent.
AT-HOME CARE
• Keep environment stable
• Reduce stressors
• Avoid punishment
WHAT A VETERINARIAN WILL CHECK
• Neurological function
• Pain evaluation
• Thyroid
• Blood pressure
• Senior bloodwork
MOST LIKELY DIAGNOSES
• Pain
• Cognitive dysfunction
• Thyroid disease
• Hypertension