The “misbehaving” performance horse: is it ever behavioral?

Most horses labeled as “misbehaving” are actually communicating discomfort or pain, and this review argues that so‑called behavioral problems in performance horses are usually rooted in physical issues. It summarizes likely medical causes, how to diagnose them, and welfare-centered management to restore comfort and performance.

What the review asks and why it matters

• Clarifies whether undesirable behaviors in performance horses are truly behavioral or more often signs of pain, illness, or equipment-related discomfort.
• Emphasizes the veterinarian’s responsibility to safeguard welfare by recognizing pain-related behaviors and preventing punitive or suppressive training responses that mask problems.
• Connects accurate diagnosis and humane management to the sport’s social license to operate, underscoring transparency and horse-first decision-making.

Key message of the review

• Most performance-limiting “behaviors” are pain- or discomfort-related rather than willful disobedience, and effective resolution depends on identifying and treating the underlying physical cause.
• Interdisciplinary assessment—veterinarian, farrier, saddler, physiotherapist, and qualified trainer/behavior professional—is central to accurate diagnosis and lasting improvement.

Common “behavioral” signs that often indicate physical problems

• Reluctance to go forward, balking, napping, or rushing: frequently linked to musculoskeletal pain, back/sacroiliac issues, or poorly fitting tack.
• Bucking, rearing, bolting: associated with thoracolumbar pain, kissing spines, sacroiliac disease, gastric pain, or sudden respiratory compromise.
• Head tossing, headshaking, mouth opening, behind-the-bit or above-the-bit carriage: dental disease, bit/bridle or noseband pressure, trigeminal-mediated headshaking, neck pain.
• Refusal to jump, stopping, run-outs, jumping “flat,” or rushing fences: forelimb or hoof pain, suspensory disease, saddle fit issues, vision or airway problems.
• Girthiness, ear pinning on saddling, tail swishing, hock “bunny hopping,” crookedness: back pain, ulcers, ill-fitting saddle, hock or stifle pathology.
• Stumbling, toe-dragging, poor transitions, asymmetry in canter leads: distal limb pain, neurologic deficits, sacroiliac or lumbosacral pain.
• Spookiness, anxiety, reluctance in specific environments: ocular disease, noise sensitivity with airway compromise, prior pain-associated contexts.
• Behavior change around breeding season or handling: reproductive tract pain or tumors (e.g., ovarian granulosa-theca cell tumor), sheath/penile pain, urinary issues.

Major categories of underlying causes

• Musculoskeletal pain: limb lameness (hoof imbalance, navicular/heel pain, suspensory desmopathy), back pain (kissing spines/overriding dorsal spinous processes), sacroiliac and pelvic issues, cervical facet osteoarthritis, myofascial pain.
• Gastrointestinal disease: equine gastric ulcer syndrome (squamous and glandular), hindgut dysbiosis or colonic discomfort, dietary management factors (meal size, forage access).
• Oral and dental problems: sharp enamel points, hooks, ulcers, fractured teeth, bit-induced lesions, wolf teeth or retained caps.
• Tack and equipment: saddle width/shape and panel pressure, bridging or rocking saddles, girth design/pressure, bit type/fit, bridle and noseband tightness, martingale or auxiliary device misuse.
• Hoof care and shoeing: long toes/low heels, mediolateral imbalance, shoeing intervals, inappropriate shoe or pad selection for the workload and footing.
• Respiratory issues: dynamic upper airway obstruction (dorsal displacement of the soft palate, recurrent laryngeal neuropathy), inflammatory airway disease/asthma, exercise-induced pulmonary hemorrhage.
• Neurologic conditions: cervical stenotic myelopathy (wobbler), equine protozoal myeloencephalitis (region-dependent), Lyme-associated syndromes (region-dependent), peripheral neuropathies including trigeminal-mediated headshaking.
• Endocrine/metabolic and muscular disorders: polysaccharide storage myopathy (PSSM), recurrent exertional rhabdomyolysis, pituitary pars intermedia dysfunction (PPID), electrolyte and energy management issues.
• Ocular disease: uveitis, cataracts, corneal scarring, subtle vision deficits affecting confidence and obstacle negotiation.
• Reproductive and urinary tract pain: ovarian pathology, endometritis, prostatic or sheath issues, kidney/bladder discomfort presenting as aversion or irritability.
• Rider, training, and workload factors: rider imbalance or asymmetry, inconsistent or contradictory aids, overfacing fences, rapid workload changes, inadequate warm-up or conditioning.
• Environment and management: limited turnout, social isolation, high-starch diets, infrequent forage, unsuitable footing, transport and competition stressors.

Recommended diagnostic approach

• Thorough history: onset, triggers (girthing, mounting, specific gaits, arenas, fences), progression, prior injuries, changes in management, diet, shoeing, tack, or rider.
• Behavioral characterization: precise description and video of the behavior in-hand, on the lunge, and under saddle; note context, intensity, and consistency.
• Comprehensive physical and lameness exam: conformation, palpation/pressure reactivity, dynamic assessment on straight lines and circles, flexion tests, ridden evaluation when safe.
• Analgesic and diagnostic anesthesia trials: response to NSAIDs or nerve/joint blocks to localize pain generators.
• Imaging as indicated: radiography (spine, limbs), ultrasonography (soft tissue, sacroiliac region), endoscopy (upper airway), gastroscopy (ulcers), advanced imaging (scintigraphy, CT/MRI) for complex cases.
• Oral and tack assessment: dental exam with sedation and speculum; professional saddle fit evaluation; bit, bridle, and noseband fit checks; pressure and symmetry assessment.
• Hoof evaluation: balance metrics, solar depth, mediolateral symmetry, shoe type and wear patterns aligned to discipline and footing.
• Laboratory testing: hematology/biochemistry, muscle enzymes, endocrine testing (PPID/insulin), infectious disease titers where regionally relevant.
• Airway and respiratory testing: resting and overground dynamic endoscopy where indicated; evaluation for asthma/IAD and EIPH management.
• Neurologic and ocular exams: cranial nerve and proprioception testing; slit-lamp and fundic exams for vision deficits.
• Rider and training review: assessment by a qualified coach; consider trial with a different rider to separate rider effects from horse discomfort.
• Multidisciplinary case conference: integrate findings across veterinary, farriery, saddle fitting, physiotherapy, and training perspectives.

Management and treatment principles

• Treat the primary cause: targeted medical therapy (e.g., omeprazole for ulcers, intra-articular therapies for synovitis, neuropathic pain strategies for headshaking), dental correction, respiratory surgery when appropriate, rehabilitation protocols for musculoskeletal pain.
• Correct contributing factors: adjust saddle and girth fit, modify bit/bridle and loosen nosebands, rebalance feet and revise shoeing schedules, optimize diet with forage-first and lower starch where indicated.
• Rehabilitation and conditioning: progressive loading plans, physiotherapy and manual therapy, core and topline development, pole and hill work, rest periods matched to tissue healing timelines.
• Training modifications: clear, consistent aids; avoid overfacing; build confidence; reward-based methods; remove gadgets that mask pain; reintroduce complexity gradually after pain resolution.
• Environment and welfare improvements: increased turnout and social contact, predictable routines, suitable footing, transport and competition stress mitigation.
• Monitor and reassess: objective outcome measures (lameness scores, rein tension metrics, rider symmetry data), regular rechecks, willingness to alter discipline or retire if comfort cannot be restored.

Implications for welfare and social license

• Recognizing pain-related behavior reduces punitive responses and supports ethical training and competition practices.
• Transparent, evidence-based management strengthens public trust and the sport’s social license by prioritizing the horse’s comfort and agency.
• Education of owners, riders, and officials about pain indicators and tack fit is essential to prevent normalizing subtle distress signs.

Limits of the evidence and research gaps

• Many associations between behaviors and pathologies are supported by clinical experience and observational studies rather than randomized trials.
• Need for standardized behavior descriptors, objective pain metrics under saddle, and validated tools for saddle/bridle pressure assessment.
• Further work on rider-horse interaction, rein tension thresholds, and discipline-specific risk profiles will refine prevention and treatment.

Practical takeaways

• Assume pain or discomfort first when a performance horse “misbehaves,” and investigate systematically before labeling a behavior as training-related.
• Do not suppress behaviors with harsher equipment or stronger aids; identify and address the root cause with a multidisciplinary team.
• Small changes—better saddle fit, hoof balance, forage access, rider symmetry—often produce large improvements in behavior and performance.
• When in doubt, pause competition goals, provide rest and diagnostics, and be prepared to modify the horse’s job to protect welfare.