Grand Rounds Case Notes: Earl the Brevard Draft Stallion with C1–C2 Atlantoaxial Instability and Penetrating Cervical Injury

Case Context and Presentation

  • Grand Rounds, fall semester; moderator introduction and housekeeping rules for in-person and Zoom attendees.
  • Time management: presenters have 18–20 minutes; moderator indicates cues at 18 and 20 minutes with a 1-minute wrap-up.
  • Presenter: Brittany Carney; co-presenter: Alyana Cook; setting: veterinary case discussion focused on a horse named Earl.
  • Animal: Earl, a two-year-old Brevard draft breed stallion; imported from Belgium as a yearling for breeding, maintained with vaccines; photos and diagnostics shown are from the case.
  • Personal connection: speaker notes Earl is now a neighbor’s horse and shares a personal journey from import to present recovery; emphasizes emotional challenge of getting a horse unstuck from entrapment.

Case Summary: Incident and Initial Stabilization

  • Event: Earl was discovered stuck underneath a gatekeeper; owner suspected he became trapped overnight and fell, with the gate mechanism collapsing on him.
  • Initial assessment on presentation: extensive recumbency, risk of secondary injury, uncertain time down, potential spinal involvement.
  • Immediate assistance: Clark Animal Rescue (volunteer branch of local fire department) called to help with extraction using heavy tools.
  • Penetrating injury noted: a bolt from the feeder had penetrated the neck between C1 and C2 and extended to the spinal column.
  • Field management before extraction: owner had oral detonation (likely analgesia) available for use; initial stabilization performed after removal from entrapment.
  • Bleeding control: precise puncture wound bleeding managed with direct pressure using gauze; a family member (the presenter’s father, a 30-year paramedic) assisted with pressure and monitoring.

Initial Clinical Findings and Concerns

  • Vitals and signs: tachycardia, tachypnea, fever; prolonged capillary refill time (> 3030 seconds) and pale mucous membranes.
  • Immediate concerns:
    • Penetrating cervical wound with potential spinal involvement.
    • Prolonged recumbency risk for rhabdomyolysis and nerve damage.
    • Respiratory compromise risk, including atelectasis, hypoxemia, aspiration pneumonia due to prior feeding while down.
    • Inability to stand initially due to energy deficit; need to support the horse to stand and assess neurological status.
  • Initial stabilization goals: support circulation, manage pain, prevent secondary injury, and monitor for systemic complications.
  • Time course: Earl stood after ~4545 minutes of efforts to regain energy and strength; eventual independent standing represented a turning point in prognosis.

Neurologic and Diagnostic Assessment

  • Neurologic exam after standing:
    • Ataxia with uncoordinated gait; proprioceptive deficits with toe dragging; reduced/absent voluntary control of hindlimbs due to fatigue and injury.
    • Neck pain; reluctance to flex neck; decreased menace response.
  • Baseline stabilization and catheterization: IV access (jugular) placed; fluids initiated to support recumbent patient and prevent shock.

Initial Medical Management and Supportive Therapy

  • Fluids and electrolytes:
    • Administered 10 L of plain fluids, followed by another 10 L with additives to address systemic consequences of recumbency and inflammation.
    • Additives included:
    • DMSO (to reduce oxidative stress and secondary injury)
    • CMPK (calcium, magnesium, phosphorus, potassium) to prevent electrolyte disturbances
    • Calcium gluconate (stabilize excitable membranes)
  • Medications given in the field:
    • NSAIDs and steroids for inflammation and pain control (protocols started early due to penetrating injury and neuroinflammation risk)
  • Diagnostic labs and timing:
    • Bloodwork performed about 4 hours after stabilization; results showed systemic stress response and muscle injury markers (details below).

Laboratory and Imaging Findings (Early)

  • Routine labs (CBC/chemistry): performed during hospitalization; notable changes included:
    • Lymphopenia (mild)
    • Hyperglycemia
    • Marked elevation of muscle enzymes indicative of rhabdomyolysis; CK extremely high (machine could not quantify in some measurements).
    • Elevated AST; mild hyperkalemia; mild hypoproteinemia (likely from third-space losses and inflammatory distribution of plasma proteins).
  • Radiographs (initial):
    • Soft tissue swelling and defects at the C1-C2 region; no abnormalities in atlanto-occipital or maxillaxo-dental joints observed at this stage.
    • Mild dorsal cranial margin rubbing at C2 spinal region.
  • Wound status: early drainage observed with pus and necrotic tissue; wound flush with Betadine solution and topical SSD; progressive debridement not yet performed.
  • CSF evaluation priority: given penetrating cervical injury and suspected spinal involvement, CSF collection and analysis were pursued to assess for infection.

Cerebrospinal Fluid (CSF) Evaluation

  • CSF collection: performed via lumbosacral puncture (standing procedure); alternative occipito-atlantoaxial approach is possible but often requires standing or anesthesia.
  • CSF culture/analysis result: no bacteria isolated; no evidence of bacterial meningitis or CSF infection at that time.
  • Diagnostic conclusion: based on imaging and neurological signs, Earl was diagnosed with C1–C2 atlantoaxial instability with clinical evidence of spinal cord compression and myelomalacia secondary to prolonged recumbency and penetrating cervical injury.

Diagnostic Conclusions and Treatment Plan (Early Hospitalization)

  • Key diagnoses:
    • C1–C2 atlantoaxial instability with spinal cord compression
    • Proprioceptive deficits and ataxia due to cervical injury
    • Penetrating cervical wound with risk of infection and CNS involvement
    • Prolonged recumbency with risk of rhabdomyolysis and systemic inflammatory response
  • Referral and monitoring: due to horse size and complexity, Earl was referred to a facility with more advanced support and resources; required 24-hour care for two weeks.
  • Therapeutic goals: stabilize vitals, manage pain and neuroprotection, control infection risk, support hydration and electrolyte balance, monitor organ function, and plan for long-term prognosis.
  • Monitoring protocol: daily (or every other day) CBC, chemistry, SAA (serum amyloid A), and fibrinogen to track inflammatory status and organ function.

Medical and Pharmaceutical Management (In-Hospital, Ongoing)

  • Fluids: continued aggressive fluid therapy totaling 162162 L during hospitalization (supportive hydration, electrolyte management, and medication vehicle).
  • Antibiotics: aggressive broad-spectrum coverage given penetrating wound and proximity to CNS; negative CSF culture did not rule out infection risk.
    • Initial antibiotics:
    • Ceftiofur sodium (NAXCEL) – broad Gram-positive and Gram-negative coverage
    • Enrofloxacin – environmental contaminants and penetrating wounds
    • Metronidazole – anaerobic coverage
    • Additional topical/systemic coverage and late-stage adjustments:
    • Cefoperazone? / benzathine topical (referred to as “Essefoprine, benzathine” in the transcript; described as topical oxytreat/tomorrow-taste but noted for aiding penetration where systemic antibiotics may not reach)
    • Chloramphenicol – CNS-penetrant broad-spectrum antibiotic used during discharge
  • Neuroprotection and analgesia:
    • Vitamin D supplementation noted as a neuroprotectant to scavenge free radicals and support cell membranes
    • Gabapentin for neuropathic pain and modulation of calcium channels to reduce excitatory neurotransmitter release
    • NSAIDs and steroids continued to address inflammation and pain control
  • Gastrointestinal protection and nutrition in the face of polypharmacy:
    • Multivitamin/anti-ulcer (broadly described as a GI protective or capsule) and probiotic supplementation
    • Bioshield-like support to protect GI mucosa (anti-ulcerative co-therapy)
  • Wound care progression:
    • Initial cleaning and topical management; subsequent wound progression to granulation through the hospitalization period
    • Wound progressed from necrotic and purulent to granulating and healing with ongoing care

Wound Course and Healing (Timeline)

  • Day 1 to near complete closure: wound evolution tracked with daily assessment; initial drainage and necrosis gradually resolved; wound eventually granulated and healed with no secondary infection reported.
  • Wound care strategy: Betadine (povidone-iodine) wash, SSD (silver sulfadiazine) application, wrapped to prevent contamination; plan for progressive debridement as healing allowed.

30-Day Post-Hospitalization Rechecks

  • Neurologic status: remained neurologically intact; persistent proprioceptive deficits but improved stability; residual ataxia decreased; cranial nerve function intact; menace response recovered.
  • Bloodwork at 30 days: parameters returned to normal ranges aside from record of prior elevated muscle enzymes resolution trend.
  • Imaging: radiographs showed soft tissue swelling and odontocervical reaction at the ventral margin of the wing of C1; subluxation at the atlantoaxial joint with dens space mildly increased.

One-Year Follow-Up and Long-Term Sequelae

  • Long-term sequelae tied to initial injury and cervical instability:
    • Neurogenic bladder developed, leading to multiple urinary tract infections (UTIs)
    • Orchitis developed in the stallion due to UTIs; semen motility and morphology compromised; not suitable for breeding
    • Cervical radiographs showed progression of osteoarthritis at the occipito-atlantal and mid-cervical joints; subchondral bone roughening and dorsal lamina fragment noted between C1 and C2
  • Management of chronic issues: NSAIDs and steroids used as needed to manage cervical osteoarthritis symptoms and inflammation

Prognosis and Outcome

  • Overall prognosis: difficult to predict; if C1–C2 stabilization remains fibrotic and infection remains controlled, the horse could live comfortably as a pasture horse
  • CT imaging feasibility: retrospective note that a standing CT could have provided definitive diagnosis of spinal cord compression, but feasibility was limited due to the horse’s size (standing CT would require a six-hour transport) and risk of movement; CT was not pursued
  • Final status: Earl remained on farm as a pasture pet; long-term challenges included neurogenic bladder and osteoarthritis, but he survived and adapted to a less intensive lifestyle
  • Final sentiment: despite odds, Earl remained alive and relatively healthy given the severity of the injury; personal gratitude extended to family, mentors, and veterinary staff

Retrospective Analysis and Practical Implications

  • Key clinical lessons:
    • Early recognition of spinal involvement in large animals with cervical penetrating trauma is critical for prognosis and management decisions.
    • Prolonged recumbency can lead to severe rhabdomyolysis and systemic inflammatory response; aggressive fluid therapy and electrolyte management are essential.
    • Multidisciplinary care and rapid collaboration with rescue services (Clark Animal Rescue) can optimize extraction and stabilization in complicated field cases.
    • CSF analysis is valuable to assess for CNS infection risk; negative results do not rule out bacterial contamination or future CNS infection in penetrating cervical injuries.
    • Imaging limitations (CT availability and feasibility) should be weighed against transport risks and potential benefits; sometimes medical management on-site is preferred.
  • Areas for potential improvement discussed by the team:
    • Consideration of advanced imaging (CT) when feasible to better define cord compression and plan interventions, though in this case transport risk outweighed potential benefit.
    • Early aggressive neuroprotective strategies and targeted antibiotic stewardship continued to be emphasized.
  • Ethical and practical implications:
    • Balancing animal welfare with the risks and costs of prolonged hospitalization and aggressive treatment in a large, high-maintenance horse.
    • Importance of documenting and sharing longitudinal outcomes to guide future cases with similar trauma profiles.

Key Numerical and Conceptual References (LaTeX-formatted)

  • Age and breed: 22 years old; Brevard draft breed stallion.
  • Weight reference used in clinical description: tissue placed to support a roughly 20002000-pound back force concern during extraction and stabilization.
  • Time references:
    • Presentation and stabilization: within hours of incident; standing attempt occurred after approx. 4545 minutes of re-support.
    • Hospitalization duration: approximately two weeks of intensive care, followed by long-term management.
    • 30-day recheck: conducted at around 3030 days post-hospitalization; later 1-year follow-up documented.
  • Fluid administration: total fluids given during hospitalization: 162162 L.
  • Neuroprotective and pharmacologic agents (examples):
    • Vitamin D (neuroprotection)
    • Gabapentin (neuronal pain modulation)
    • Ceftiofur sodium (NAXCEL) – broad coverage; Enrofloxacin; Metronidazole; Chloramphenicol for CNS penetration; topical cephalosporin preparation described in the transcript as “Essefoprine, benzathine.”
  • Diagnostic findings (conceptual):
    • CSF: no bacterial growth on culture; no evidence of meningitis at time of sampling.
    • Radiographs: C1–C2 region involvement with atlantoaxial instability; preserved atlantooccipital and maxillaxo-dental joints at initial imaging; later radiographs noted subluxation and dens space changes.

Connections to Foundational Principles and Real-World Relevance

  • Trauma management in large animals: emphasizes rapid stabilization, neuroprotective strategies, and comprehensive wound care.
  • Neuroanatomy and biomechanics: C1–C2 instability leading to spinal cord compression explains ataxia and proprioceptive deficits.
  • Infectious disease risk with penetrating injuries: CSF analysis and broad-spectrum antibiotics employed to mitigate risk to CNS.
  • Critical care logistics: demonstrates complex coordination between owners, local rescue services, and specialized facilities.
  • Long-term quality of life considerations: prognosis for a massive equine patient after cervical injury includes neurogenic issues, chronic pain management, and arthritis, influencing decisions about breeding use and lifestyle.

References and Acknowledgments

  • Acknowledgment of clinical mentors and support network (Tuskegee team and colleagues).
  • Clark Animal Rescue involvement and community veterinary collaboration.
  • Final slide thanks include family, friends, and mentors; case references provided by the presenter’s team and cited as the basis for the discussed clinical practices.