Internal parasites, bacterial/viral infection
| Illness or disease | Altered personality, lethargy, depression, withdrawal, anorexia, reduction in grooming, altered social relationships, altered response to stimuli |
Central (affecting forebrain, limbic/temporal, and hypothalamic), rapid-eye movement sleep disorders
| Neurologic | Altered awareness and response to stimuli, loss of learned behaviors, housesoiling, disorientation, confusion, altered activity levels, temporal disorientation, vocalization, change in temperament (fear, anxiety, aggression), altered appetite, altered sleep cycles, interrupted sleep (aggression/waking/activity) |
| Peripheral (neuropathy) | Neurologic | Self-mutilation, irritability, aggression, circling, hyperesthesia |
| Focal seizures/temporal lobe seizures | Neurologic | Repetitive behaviors, self-trauma, chomping, staring, altered temperament (eg, intermittent states of fear or aggression), tremors, shaking, interrupted sleep |
| Sensory dysfunction | Neurologic | Altered response to stimuli, confusion, disorientation, altered sleep cycles, irritability, aggression, vocalization, housesoiling |
| Hypothyroidism | Metabolic / Endocrine | Lethargy, decreased response to stimuli, irritability, aggression. |
| Hyperadrenocorticism (Cushing's disease) | Metabolic / Endocrine | Panting, night waking, housesoiling, irritability, polydipsia, polyphagia, anxiety |
| Diabetes/hyperglycemia | Metabolic / Endocrine | Housesoiling, night waking |
| Functional ovarian and testicular tumors | Physical | Androgen-induced behaviors: males—aggression, roaming, marking, sexual attraction, mounting; females—nesting or possessive aggression of objects |
| Hepatic or renal encephalopathy | Physical | Signs associated with affected organ, anxiety, irritability, aggression, altered sleep, housesoiling, mental dullness, decreased activity, restlessness, increased sleep, confusion |
| Anemia or electrolyte imbalances | Physical | Pica |
| Pain | Pain | Altered response to stimuli, decreased activity, restlessness/inability to settle, vocalization, housesoiling, aggression, irritability, self-trauma, waking at night |
| Gastrointestinal | Physical | Licking, polyphagia, pica, coprophagia, housesoiling (fecal), wind sucking, tongue rolling, unsettled sleep, restlessness |
| Urogenital | Physical | Housesoiling (urine), polydipsia, waking at night |
| Dermatologic | Physical | Acral lick dermatitis, nail biting, hyperesthesia, other self-trauma |
Responses