All EMS presentations
EnvironmentalClinical presentation

Animal bite / envenomation

A streamlined, differential-led presentation for rapid clinical review.

Clinical snapshot

Twenty-second review

  • Animal bites cause puncture or crush injury, contamination, bleeding, and possible venom effects; location and species influence infection and systemic risk.
  • Airway reaction, neurotoxicity, shock, uncontrolled bleeding, hand or face injury, deep puncture, or rapidly progressive swelling is high risk.
  • Keep cellulitis or retained foreign body in the differential; overlapping or concurrent illness remains possible.
  • For animal bite / envenomation, trends and combinations of findings are more informative than one isolated vital sign.
Differentials

Compare the clinical patterns

The repeated material is grouped inside each possibility. Open only the condition you need.

Serious3 conditions
EnvenomationTime-sensitive high-risk possibility

HPI

Clarify animal and time of exposure; bite location and wound; swelling progression.

Signs & symptoms

Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.

Focused exam

Expose appropriately, assess core temperature when available, inspect skin, and look for trauma or multisystem involvement; Reassess after decontamination, warming, cooling, or oxygen support.

Brief pathophysiology

Envenomation may cause animal bite / envenomation through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Environmental illness is defined by exposure plus physiology. Temperature, heart rate, pressure, and respiratory rate help grade systemic effect and response to removal or treatment.

Temperature (°C)

High or low

Use an appropriate measurement method for the suspected exposure.

Heart rate (bpm)

May rise or fall

Rate varies with temperature, dehydration, toxicity, and severity.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, vasodilation, or advanced illness.

Respiratory rate (breaths/min)

May rise or fall

Respiratory response depends on temperature, inhalation injury, and metabolic state.

Front-load in the triage report

  • Envenomation: Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.
  • Animal and time of exposure?
  • Bite location and wound?
AnaphylaxisTime-sensitive high-risk possibility

HPI

Clarify bite location and wound; swelling progression; allergic or systemic symptoms.

Signs & symptoms

Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.

Focused exam

Reassess after decontamination, warming, cooling, or oxygen support; Ensure scene safety; inspect wound depth and location, distal CSM, swelling progression, systemic allergy, species, and immunization history.

Brief pathophysiology

Anaphylaxis may cause animal bite / envenomation through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Anaphylaxis may involve airway, breathing, or circulation alone or in combination. Do not wait for hypotension, hypoxemia, or skin findings before recognizing a severe reaction.

Blood pressure (mmHg)

May fall

Vasodilation and capillary leak can cause rapid hypotension.

Heart rate (bpm)

Often rises

Tachycardia may accompany shock, distress, or epinephrine treatment.

Respiratory rate (breaths/min)

Often rises

Tachypnea may reflect bronchospasm, airway edema, or shock.

Oxygen saturation (SpO₂)

May fall

Desaturation suggests significant respiratory involvement but may be late.

Front-load in the triage report

  • Anaphylaxis: Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.
  • Bite location and wound?
  • Swelling progression?
Deep structure injuryTime-sensitive high-risk possibility

HPI

Clarify swelling progression; allergic or systemic symptoms; tetanus and immune status.

Signs & symptoms

Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.

Focused exam

Reassess after decontamination, warming, cooling, or oxygen support; Ensure scene safety; inspect wound depth and location, distal CSM, swelling progression, systemic allergy, species, and immunization history.

Brief pathophysiology

Deep structure injury may cause animal bite / envenomation through a time-sensitive process capable of rapid physiological deterioration.

Vital-sign pattern

What the trend may show

Possible pattern

Environmental illness is defined by exposure plus physiology. Temperature, heart rate, pressure, and respiratory rate help grade systemic effect and response to removal or treatment.

Temperature (°C)

High or low

Use an appropriate measurement method for the suspected exposure.

Heart rate (bpm)

May rise or fall

Rate varies with temperature, dehydration, toxicity, and severity.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, vasodilation, or advanced illness.

Respiratory rate (breaths/min)

May rise or fall

Respiratory response depends on temperature, inhalation injury, and metabolic state.

Front-load in the triage report

  • Deep structure injury: Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.
  • Swelling progression?
  • Allergic or systemic symptoms?
Common1 condition
Local bite woundCommon presentation pattern

HPI

Clarify animal and time of exposure; bite location and wound; swelling progression.

Signs & symptoms

Pain, puncture, and contamination may be limited initially.

Focused exam

Expose appropriately, assess core temperature when available, inspect skin, and look for trauma or multisystem involvement; Reassess after decontamination, warming, cooling, or oxygen support.

Brief pathophysiology

Local bite wound may explain the presenting symptoms through a common clinical mechanism, while serial assessment checks for complications or an alternate cause.

Vital-sign pattern

What the trend may show

Possible pattern

A localized reaction generally preserves breathing and circulation. Any airway symptom, respiratory compromise, or hypotension should trigger reassessment for anaphylaxis.

Blood pressure (mmHg)

Usually preserved

Falling pressure is not expected in a localized reaction.

Respiratory rate (breaths/min)

Usually normal

New respiratory distress suggests systemic involvement.

Oxygen saturation (SpO₂)

Usually normal

Desaturation suggests respiratory involvement or another condition.

Heart rate (bpm)

Usually near baseline

Pain or anxiety may increase rate; persistent tachycardia warrants reassessment.

Front-load in the triage report

  • Pain, puncture, and contamination may be limited initially.
  • Animal and time of exposure?
  • Bite location and wound?
Mimics2 conditions
CellulitisImportant alternative presentation

HPI

Clarify animal and time of exposure; bite location and wound; swelling progression.

Signs & symptoms

Infection or tooth fragments may complicate the wound.

Focused exam

Expose appropriately, assess core temperature when available, inspect skin, and look for trauma or multisystem involvement; Reassess after decontamination, warming, cooling, or oxygen support.

Brief pathophysiology

Cellulitis can resemble animal bite / envenomation through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Environmental illness is defined by exposure plus physiology. Temperature, heart rate, pressure, and respiratory rate help grade systemic effect and response to removal or treatment.

Temperature (°C)

High or low

Use an appropriate measurement method for the suspected exposure.

Heart rate (bpm)

May rise or fall

Rate varies with temperature, dehydration, toxicity, and severity.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, vasodilation, or advanced illness.

Respiratory rate (breaths/min)

May rise or fall

Respiratory response depends on temperature, inhalation injury, and metabolic state.

Front-load in the triage report

  • Infection or tooth fragments may complicate the wound.
  • Animal and time of exposure?
  • Bite location and wound?
Retained foreign bodyImportant alternative presentation

HPI

Clarify bite location and wound; swelling progression; allergic or systemic symptoms.

Signs & symptoms

Infection or tooth fragments may complicate the wound.

Focused exam

Reassess after decontamination, warming, cooling, or oxygen support; Ensure scene safety; inspect wound depth and location, distal CSM, swelling progression, systemic allergy, species, and immunization history.

Brief pathophysiology

Retained foreign body can resemble animal bite / envenomation through overlapping symptoms or referred physiology despite a different primary mechanism.

Vital-sign pattern

What the trend may show

Possible pattern

Environmental illness is defined by exposure plus physiology. Temperature, heart rate, pressure, and respiratory rate help grade systemic effect and response to removal or treatment.

Temperature (°C)

High or low

Use an appropriate measurement method for the suspected exposure.

Heart rate (bpm)

May rise or fall

Rate varies with temperature, dehydration, toxicity, and severity.

Blood pressure (mmHg)

May fall

Hypotension suggests dehydration, vasodilation, or advanced illness.

Respiratory rate (breaths/min)

May rise or fall

Respiratory response depends on temperature, inhalation injury, and metabolic state.

Front-load in the triage report

  • Infection or tooth fragments may complicate the wound.
  • Bite location and wound?
  • Swelling progression?
Red flags

Findings that should escalate concern

  • Airway reaction, neurotoxicity, shock, uncontrolled bleeding, hand or face injury, deep puncture, or rapidly progressive swelling is high risk.
  • Envenomation, anaphylaxis, or deep structure injury: Progressive swelling, systemic symptoms, neurovascular change, or airway involvement.
Related medications

Medication recognition

AmoxicillinApixabanRivaroxabanClopidogrelCephalexinWarfarin
Related EMS presentations

Continue the clinical pathway

TraumaLaceration / external hemorrhageAllergic/ImmunologicAllergic reaction / anaphylaxisToxicologyPoisoning / toxic exposureInfectiousCellulitis / soft-tissue infectionAllergic/ImmunologicAngioedema
References

Clinical and academic sources

Curated clinical guidance and peer-reviewed evidence supporting this presentation. Current BCEHS guidance, medical direction, and local policy remain authoritative for practice.

BCEHS Handbook — specific CPGs

  1. J01: Approach to Chemical or Toxic ExposuresBC Emergency Health Services Handbook

    Official BCEHS clinical practice guidance for approach to chemical or toxic exposures.

Supporting clinical and academic evidence

  1. CEDIS Presenting Complaint List updateCanadian Association of Emergency Physicians

    Presenting-complaint terminology and categorization context. It does not establish a prehospital “top 100” ranking.

  2. Clinical Practice Guideline SummariesWilderness Medical Society

    Evidence-based guidance for environmental and wilderness emergencies, including heat, cold, altitude, and drowning.

  3. Animal Bites and AttacksEmergency Medicine Clinics of North America · 2024

    Wound assessment, hemorrhage, infection, rabies/tetanus context, and envenomation considerations.