Overview and Clinical Importance
Understanding animal behavior is fundamental to veterinary practice. Behavior assessment allows veterinarians to recognize normal versus abnormal behaviors, identify stress and fear in patients, ensure safe handling during examinations, improve patient welfare, and provide appropriate recommendations for environmental enrichment and behavioral modification.
Behavior problems are the leading cause of pet relinquishment to shelters and a primary reason for euthanasia requests. Entry-level veterinarians must be able to recognize behavioral signs of stress, fear, and anxiety to provide optimal patient care and prevent injury to both animals and staff.
Section 1: Species-Appropriate Behavior
Species-appropriate behavior refers to the normal behavioral repertoire that animals display when their physical, social, and psychological needs are met. Understanding these behaviors is essential for recognizing when animals are experiencing distress or displaying abnormal patterns.
Canine Normal Behavior
Dogs are social, pack-oriented animals with complex communication systems. Normal canine behaviors include social greeting (approaching with relaxed body, soft eyes, and wagging tail), play behavior (play bows, chase, and wrestling), territorial marking (urination at strategic locations), exploration and investigation (sniffing, mouthing objects), resting and sleep cycles (12-14 hours daily for adults), and communication through vocalizations, body postures, and facial expressions.
[Include Image: Figure 1. Relaxed dog body language showing soft eyes, loose body posture, and neutral tail position]
MEMORY AID - DOGS Social Behaviors: D = Dominance displays are contextual (not fixed hierarchy), O = Orientation toward owner shows attachment, G = Greetings involve whole body, S = Submission is voluntary and adaptive
Normal Canine Body Language Indicators
Feline Normal Behavior
Cats are crepuscular predators with strong territorial instincts. Normal feline behaviors include hunting sequences (stalk, pounce, capture, kill bite), scent marking (facial rubbing, scratching, urine marking in intact cats), grooming (30-50% of waking hours), vertical space utilization (climbing, perching), sleep patterns (12-16 hours daily), and social behaviors (allogrooming, allorubbing with familiar individuals).
[Include Image: Figure 2. Cat displaying relaxed body language with slow blink and forward-facing ears]
MEMORY AID - CAT Body Parts: C = Constricted pupils indicate arousal or stress, A = Airplane ears (sideways) signal discomfort, T = Tail position indicates mood (up = confident, tucked = fearful)
Feline Ear Position Meanings
Equine Normal Behavior
Horses are prey animals with strong herd instincts and flight responses. Normal equine behaviors include grazing patterns (16-18 hours daily in natural conditions), social bonding and mutual grooming, herd hierarchy establishment, vigilance and sentinel behavior, rolling and dust bathing, and flight response to perceived threats.
[Include Image: Figure 3. Horse demonstrating normal grazing and social behaviors in herd setting]
MEMORY AID - HORSE Flight Response: H = Hear first (ears rotate), O = Orient to threat, R = Ready posture (head up, muscles tense), S = Startle and flee, E = Evaluate once safe distance achieved
Bovine Normal Behavior
Cattle are social ruminants with complex communication systems. Normal bovine behaviors include rumination cycles (8 hours daily), herd movement patterns, social hierarchy establishment, maternal behaviors, thermoregulatory behaviors (seeking shade, water immersion), and flight zone responses. Cattle have panoramic vision (approximately 330 degrees) but limited depth perception, which influences their handling requirements.
MEMORY AID - CATTLE Vision: C = Cannot see directly behind, A = Almost 330 degree vision, T = Two blind spots (front and rear), T = Threshold for flight varies individually, L = Limited depth perception, E = Evaluate shadows carefully
Small Ruminant and Porcine Behavior
Sheep and goats are highly social prey animals with strong flocking/herding instincts. Normal behaviors include following behavior in sheep (stronger than in goats), browsing versus grazing preferences (goats browse, sheep graze), social hierarchy establishment, maternal bonding, and flight responses. Pigs are omnivorous, highly intelligent social animals whose normal behaviors include rooting and foraging (up to 75% of active time), nest building, wallowing for thermoregulation, social hierarchy establishment, and exploratory behaviors.
Section 2: Stress Indicators by Species
Stress is defined as any chemical, physical, or emotional force that threatens homeostasis. The stress response involves activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary (SAM) system, resulting in cortisol and catecholamine release. Chronic stress leads to immunosuppression, behavioral abnormalities, and reduced welfare.
Physiological Stress Indicators (All Species)
Canine Stress Indicators
[Include Image: Figure 4. Dog showing stress signals including whale eye, lip licking, and lowered body posture]
Subtle (Early) Stress Signs in Dogs
Veterinary students often miss subtle stress indicators. These include lip licking or tongue flicking (when not hungry), yawning (when not tired), looking away or averting gaze, paw lifting, scratching or grooming out of context, wet footprints (sweating through paw pads), slow blinking, half-moon eye (whale eye showing sclera), sniffing the ground excessively, and shake-off behavior (fur shake when not wet).
MEMORY AID - YAWNS Stress Signs: Y = Yawning out of context, A = Averting gaze away, W = Whale eye (whites showing), N = Nose licking, S = Shake-off behavior
Obvious Stress Signs in Dogs
More obvious stress indicators include tucked tail, flattened ears against head, lowered body posture or cowering, piloerection (raised hackles), trembling or shaking, excessive panting (when not hot), excessive drooling, attempting to escape or hide, freezing (complete stillness), and vocalizations (whining, whimpering, barking).
Feline Stress Indicators
[Include Image: Figure 5. Stressed cat displaying flattened ears, dilated pupils, and tense body posture]
Feline Stress Signs Table
MEMORY AID - CAT Fear Posture: C = Crouching low, A = Airplane or flattened ears, T = Tail tucked or puffed
Equine Stress Indicators
Horses display stress through multiple channels. Common indicators include elevated head carriage, ears pinned back or constantly moving, wide eyes showing sclera, flared nostrils, increased respiratory rate, pawing, weaving or pacing, sweating without exertion, defecation or urination, tail swishing or clamping, and refusal to move forward or attempting to flee.
Bovine and Farm Animal Stress Indicators
Cattle stress indicators include bellowing or vocalizations, attempting to flee, kicking or charging, defecation, elevated tail, increased heart and respiratory rates, sweating, and bunching behavior in groups. Sheep typically show bunching behavior, rapid respiration, wide eyes, stamping feet, and high-pitched bleating. Pigs demonstrate vocalization (high-pitched squealing), escape attempts, bar biting, decreased feed intake, and tail biting when chronically stressed.
MEMORY AID - FARM Stress Signs: F = Flight attempts, A = Altered vocalizations, R = Respiratory rate increased, M = Movement (excessive or frozen)
Section 3: Abnormal Behavior Recognition
Abnormal behaviors in animals fall into several categories and must be distinguished from normal behaviors performed at inappropriate times or intensities. Understanding the distinction between stereotypies, compulsive disorders, and displacement behaviors is essential for appropriate diagnosis and management.
Definitions and Categories
Equine Stereotypic Behaviors
Stereotypic behaviors in horses affect approximately 5-15% of the domestic population and are never observed in free-ranging wild horses. These behaviors are linked to confinement, lack of social contact, restricted foraging opportunities, and high concentrate diets. Importantly, stereotypies are NOT learned through observation from other horses - this is a common misconception.
[Include Image: Figure 6. Horse demonstrating cribbing behavior grasping fence with incisors]
Common Equine Stereotypies
MEMORY AID - CRIB Risk Factors: C = Concentrate-heavy diet, R = Restricted turnout, I = Isolation from other horses, B = Boredom from lack of enrichment
Canine Compulsive Disorders
Canine compulsive disorders are characterized by repetitive behaviors that interfere with normal daily function. They often develop from displacement behaviors that become fixed over time. There is evidence of genetic predisposition in certain breeds, and altered serotonergic and dopaminergic neurotransmission plays a role.
Feline Compulsive and Abnormal Behaviors
Common feline compulsive disorders include psychogenic alopecia (overgrooming causing hair loss, often on ventral abdomen), wool sucking/pica (sucking or ingesting fabric, especially in Siamese and Burmese), tail chasing or self-mutilation, and excessive vocalization. These must be distinguished from medical causes - dermatologic conditions, hyperthyroidism, pain, and gastrointestinal disease can all cause similar presentations.
MEMORY AID - FELINE Overgrooming DDx: F = Flea allergy dermatitis, E = Ectoparasites, L = Lymphoma/neoplasia, I = Infection (fungal/bacterial), N = Neuropathy/pain, E = Environmental/psychogenic
Farm Animal Abnormal Behaviors
In pigs, common abnormal behaviors include tail biting (major welfare concern in intensive housing), bar biting and chain chewing, belly nosing, and excessive aggression. These are strongly associated with inadequate environmental enrichment, overcrowding, and restricted foraging opportunities. In cattle, tongue rolling, excessive licking of fixtures, and inter-sucking in group-housed calves are recognized abnormal behaviors.
Section 4: Environmental Enrichment
Environmental enrichment is defined as the process of enhancing an animal's environment to increase physical activity, fulfill psychological needs, and encourage species-typical behavior. Enrichment reduces stress, increases animal welfare, and promotes overall health by increasing an animal's perception of control over their environment.
Five Categories of Environmental Enrichment
MEMORY AID - SNOPS Enrichment Categories: S = Social (conspecifics), N = Nutritional (foraging), O = Occupational (cognitive), P = Physical (structural), S = Sensory (five senses)
Species-Specific Enrichment Recommendations
Canine Enrichment
Dogs benefit from daily walks and exercise, interactive toys and puzzle feeders, training sessions using positive reinforcement, social play with compatible dogs, scent work and nose games, chewing opportunities with appropriate items, novel environments and experiences, and regular human social interaction.
[Include Image: Figure 7. Dog engaged with puzzle feeder toy demonstrating cognitive enrichment]
Feline Enrichment
Cats require vertical space including cat trees, shelves, and perches, horizontal hiding spots, scratching posts of various materials, interactive play sessions simulating hunting, food puzzle feeders, window perches for environmental viewing, varied substrates and textures, and for outdoor access consideration, catios (enclosed outdoor spaces). The indoor cat initiative recommends multiple resource locations to reduce competition in multi-cat households.
[Include Image: Figure 8. Cat utilizing vertical space on cat tree demonstrating environmental enrichment]
MEMORY AID - CAT Resources Rule: C = Climbing spaces for vertical territory, A = Add one more (n+1 resources for n cats), T = Territorial separation (multiple locations)
Equine Enrichment
Horses require maximum turnout time in pasture, social contact with compatible horses, ad libitum forage access (reduces oral stereotypies), varied exercise routines, slow feeders to extend foraging time, stable mirrors for isolated horses, windows and views outside stall, and toys such as balls and hanging objects.
Farm Animal Enrichment
For cattle, enrichment includes pasture access and rotational grazing, scratching posts and brushes, social housing, and varied feeding methods. Pigs benefit greatly from rooting substrates such as straw or wood shavings, foraging opportunities, novel objects for investigation, social housing, and wallowing opportunities. For poultry, enrichment includes perching, dust bathing areas, foraging opportunities, pecking substrates, and adequate space.
MEMORY AID - PIG Enrichment Priority: P = Provision of rooting material, I = Investigate novel objects, G = Group housing for social needs
Enrichment in Veterinary Practice
Hospitalized patients and those in shelter environments have specific enrichment needs. Strategies include species-appropriate bedding and hiding spaces, pheromone diffusers (Adaptil for dogs, Feliway for cats), calming music (classical music shown beneficial), reduced visual and auditory stressors, gentle handling and positive interactions, and adequate space for movement.
Section 5: Clinical Integration and Practical Application
Behavioral assessment should be integrated into every patient interaction. This section covers practical application of behavioral knowledge in clinical settings.
Fear-Free Veterinary Practice Principles
Fear-Free handling incorporates understanding of species-specific behavior and stress indicators. Key principles include reading and responding to early stress signals, providing control and choice when possible, using species-appropriate handling techniques, minimizing time in stressful environments, employing pheromone therapy when appropriate, using food rewards to create positive associations, avoiding confrontational restraint methods, and allowing breaks during procedures.
When to Refer for Behavioral Consultation
Veterinary behaviorists (Diplomates of ACVB) provide specialized care for complex behavioral issues. Referral is appropriate for aggression causing injury or risk of injury, severe anxiety disorders not responsive to initial treatment, compulsive disorders affecting quality of life, behavioral problems unresponsive to basic management, and cases requiring behavioral medication management.
Pharmacological Considerations
While detailed pharmacology falls under Domain 2, behavioral medications commonly used include SSRIs such as fluoxetine for compulsive disorders and anxiety, TCAs such as clomipramine for separation anxiety and compulsive disorders, benzodiazepines for acute anxiety situations, trazodone for situational anxiety, and alpha-2 agonists for sedation during procedures. Environmental management and behavior modification should always accompany pharmacotherapy.