Emergency Triage and the Primary Survey

Introduction

Triage is the method of assigning priority to emergency patients and their problems, based on a rapid look at the history and the physical findings.¹ In most hospitals the technician is the first trained person to see the patient, and often the first to hear about it on the phone. Your job is to spot the animal that cannot wait, move it to the treatment area, call the veterinarian, and start the primary survey. You also keep reassessing the patients who seemed stable at the door. The VTNE lists triage as its own task in the emergency domain, so expect questions on what to check first and what to do next.

Key facts

How the VTNE tests this

• Prioritize: "Perform triage of a patient presenting with emergency/critical conditions (including but not limited to shock, acute illness, acute trauma, and toxicity)" is Domain 8 Task B.⁹ Expect "which patient is seen first" and "which step comes first".
• Interpret a finding: a gum color, a CRT, a heart rate in a cat, a breathing pattern, and choose the triage priority.
• Reassess: Domain 8 Task E covers ongoing evaluation of physical, behavioral, nutritional and mentation status in emergency and critical patients.⁹ The Rule of 20 and the MGCS belong here.
• Advise by phone: what to ask the owner and what first aid to give or avoid. Knowledge area K35 is "Animal first aid, triage, and emergency/critical care techniques".⁹
• Calculate: blood loss in mL from a body weight and a hemorrhage class.

Core concepts

Why order matters

A problem with airway, breathing or circulation quickly cuts oxygen delivery to the tissues. The cells switch to anaerobic metabolism and lactic acid builds up.² An animal can survive a broken leg for hours. It cannot survive a blocked airway for minutes. That is why triage ranks problems by how fast they kill, not by how dramatic they look. A text on trauma care notes that big musculoskeletal injuries get a relatively low priority during initial triage of an injured animal.⁸

The major body systems

The primary survey looks at the respiratory, cardiovascular, neurologic and urinary systems.⁷ These are the "major body systems" in triage questions. Merck lists difficulty urinating or inability to urinate in male cats as a complaint that goes straight to the treatment area.¹

XABCDE, letter by letter

• X, eXsanguination: obvious catastrophic external bleeding, or bleeding into a body cavity.¹
• A, airway: is it clear and open? Partial obstruction of the large airway causes noisy breathing (stridor or stertor) that you can hear without a stethoscope.¹
• B, breathing: respiratory rate, effort and oxygenation.¹
• C, circulation: heart auscultation, heart rate, pulse quality, gum color, CRT and blood pressure.¹
• D, disability: evidence of head or spinal injury or disease, from the brain and cranial nerves to the spinal cord and peripheral nerves.¹
• E, exposure and environment: body temperature, sources of heat loss, and open wounds anywhere on the body.¹

Do not forget pain. Merck notes that a dog in substantial pain or anxiety can look like it is in compensatory shock, so appropriate analgesics are warranted.¹ Many older texts and exam items use plain ABC or ABCDE. The order of A, B and C is the same in every version.

Recognizing shock at the door

Shock means poor perfusion of the tissues. Merck describes three stages.¹

• Early compensatory (dogs): fast heart rate, pink to red gums, rapid CRT, bounding pulses, usually alert. A persistent fast heart rate is often the first and only sign. Pain and anxiety can look the same, so treat pain and let the patient settle.
• Middle, or early decompensatory: dogs have pale gums, prolonged CRT, weak pulses, fast heart rate and duller mentation. Cats have gray gums, slow CRT, weak or absent pulses, low body temperature and a normal or low heart rate.
• Terminal, or late decompensatory: heart rate slows in both species, with severe low blood pressure, absent pulses, gray or ashen gums, prolonged CRT, altered mentation and abnormal breathing. Cardiopulmonary arrest often follows.

Recognizing respiratory distress

Failing breathing shows first as a faster rate and more effort, then a change in pattern, then a change in posture. Orthopnea is breathing distress shown by posture: dogs stand with elbows abducted and head and neck extended, and cats crouch on all four limbs with the sternum slightly raised. Open-mouth breathing and gray, dark pink or blue gums come last and signal that respiratory arrest may be near.¹ Pleural space disease (air or fluid around the lungs) causes asynchronous breathing: the chest expands while the abdomen is pulled in. Stressful procedures such as radiographs can make these patients crash.¹

Procedure or technique

Phone triage

1. Ask short, targeted questions. Merck lists level of consciousness, breathing pattern, type of injury or toxin, and, if safe to check, gum color, responsiveness and heart rate.⁴ Ask when the pet was last completely normal and, for a toxin, what it was, how much and how long ago.⁸ Do not keep the client on the phone too long; the full history can wait until the pet is in the hospital.⁸
2. Protect the owner first. A light cloth over the head reduces stimuli. Most dogs can be muzzled with a long strip of fabric if there are no facial injuries or breathing difficulty. Cats travel in a dark box with air holes.⁴
3. Give safe first aid only. Direct pressure or a pressure bandage on bleeding.⁴ A flat, firm surface and minimal head, neck and spine movement after suspected trauma.⁴ Move a heat stroke patient to a cool place, cool it, and transport it right away.⁵ No blind finger sweep of the mouth, because it can push an object deeper.⁵
4. For a toxin, say "come in now". RECOVER recommends against routine prehospital emetics. It suggests them only when a veterinary facility cannot be reached right away and a veterinarian or animal poison control center recommends emesis.⁵ Hydrogen peroxide given at home can cause a vagal collapse, choking, aspiration pneumonia or mucosal injury. Ask the owner to bring the container or a photo of the label.⁴
5. Record and alert. Note the call time, the advice given and the expected arrival time, and warn the veterinarian and the treatment area.

Triage at the door

1. Look before you touch. From a distance, note mentation, posture, breathing effort and any bleeding. Distant observation comes before imaging and other tests in a breathing patient.¹
2. Check the stat list. If the complaint is on the list in Table 1, move the patient to the treatment area for immediate veterinary evaluation, whatever the vital signs show.¹
3. Take the triage vital signs: temperature, pulse rate, respiratory rate, level of consciousness and pain, plus pulse quality, gum color and CRT.⁴ Palpate femoral and digital pulses.¹
4. Act on the first failing step of XABCDE. Apply direct pressure to bleeding.¹ Give oxygen by flow-by, mask, hood, nasal line or cage to the patient in distress, with as little restraint as possible.¹
5. Assign a category and record it with arrival time, signalment, complaint and vital signs.
6. Reassess. A patient in the waiting room can worsen. Repeat vital signs and move the patient up if they change.

The secondary survey

Once the primary survey and initial stabilization are done, the secondary survey collects a full history, a complete physical examination and general diagnostic data.² Merck suggests an initial minimum database of packed cell volume (PCV), total solids, glucose and BUN.² The mnemonic A CRASH PLAN gives a head-to-tail order: airway; cardiovascular and respiratory; abdomen; spine; head; pelvis; limbs; arteries; nerves.⁸

Source: stat complaints from the Merck Veterinary Manual list of problems that warrant transfer to the treatment area regardless of physical findings;¹ actions from Merck and RECOVER first aid guidance.⁴⁵ Priority labels are a teaching summary; each hospital sets its own.

Source: Merck Veterinary Manual, table "Parameters to Evaluate During Triage".¹ Other references give other heart rate ranges; see the physical exam guide.

Triage categories

There is no single standard veterinary triage system. The Veterinary Triage List and VetTriS have been described, and some clinics adapt the human Manchester Triage System.⁶ One 2026 study of 4,579 after-hours visits used five color levels with treatment windows: red (immediate), orange (very urgent, under 10 minutes), yellow (urgent, under 30 minutes), green (standard, under 90 minutes) and blue (non-urgent, under 120 minutes).⁶ In that study cats were placed in the red category about three times as often as dogs.⁶ Learn your hospital's system; on the exam, rank by threat to life.

Flowchart

Species differences

• Cats in shock often have a normal or slow heart rate, gray gums and low body temperature. A cat with a heart rate that looks "normal for a dog" may be very sick.¹ Merck recommends small-volume fluid resuscitation for all cats in hypovolemic shock, because they have a smaller blood volume.¹
• Cats in respiratory distress crouch with the sternum slightly raised, and their asynchronous breathing is slower and more deliberate than a dog's.¹ Handle them as little as possible.
• Male cats that strain without passing urine are always a stat complaint.¹
• Dogs in early shock show a fast heart rate, red gums, rapid CRT and bounding pulses.¹
• Small, young and old animals are at higher risk of hypothermia.¹
• Horses and food animals follow the same ABC priorities, but this guide's numbers are for dogs and cats only.

Calculation

Merck grades hemorrhage in four classes by the percentage of blood volume lost. Class II (mild) is 15 to 30 percent, which Merck gives as 13 to 26 mL/kg in the dog and 9 to 18 mL/kg in the cat. Class II patients show a fast heart rate, bounding pulses and a rapid CRT, and usually need resuscitation.¹

Merck also says any blood lost in the hospital should be measured or estimated, for example by collecting it in a closed system or weighing soaked gauze.¹

Ongoing monitoring: the Rule of 20 and the MGCS

Triage does not stop when the patient is admitted. Kirby's Rule of 20 lists 20 parameters to review at least daily in every critically ill animal. The aim is to catch organ problems before organ failure: "anticipation, not reaction".³ The 20 items are:³

Source: Merck Veterinary Manual, Monitoring the Critically Ill Small Animal Using the Rule of 20 (section list).³ The grouping is a study aid, not part of the original list.

For patients with head injury, the MGCS scores motor activity, brainstem reflexes and level of consciousness from 1 (severely abnormal) to 6 (normal) each, for a total of 3 to 18. Scores of 15 to 18 are classed as good, 9 to 14 as guarded and 3 to 8 as grave.⁷ Merck calls the MGCS a useful monitoring tool for neurological injury, and the technician records it serially so a falling score is caught early.² The Animal Trauma Triage (ATT) score grades six areas (perfusion, cardiac, respiratory, eye/muscle/integument, skeletal, neurologic) from 0 to 3 each, for a total of 0 to 18. Higher ATT scores mean more severe injury.⁷ Notice that the two scales run in opposite directions.

Safety, legal and client education

• Owner safety first, on the phone and in the parking lot. Injured, frightened animals bite.⁴
• Do not muzzle an animal with facial injuries or breathing difficulty.⁴
• Tourniquets are for limbs and tails when compression has failed.⁴ In the hospital, Merck says a tourniquet should not stay on for more than 10 minutes.¹
• Heat stroke: RECOVER suggests cooling to a rectal temperature of 39.7 to 40 °C (103.5 to 104.0 °F) and then stopping active cooling.⁵
• Burns: cool running tap water for at least 20 minutes, as soon as possible and within 3 hours of injury.⁵
• Warming: avoid hot water bottles and hot rice bags because of burn risk.¹
• Scope: the technician triages, records and starts first aid; the veterinarian diagnoses and prescribes. Phone advice should be first aid and "come in now", not a diagnosis.
• Records: write down call times, advice given, arrival time, vital signs and triage category. A good record shows that an urgent patient was seen promptly.

Common mistakes and exam traps

Quick review

1. Triage assigns priority by rapid history and physical findings.
2. Primary survey first, secondary survey after stabilization.
3. XABCDE: eXsanguination, airway, breathing, circulation, disability, exposure.
4. Major body systems: respiratory, cardiovascular, neurologic, urinary.
5. Check temperature, pulse, respiration, mentation and pain on every arrival.
6. CRT 1 to 2 seconds is normal; over 2 seconds is poor perfusion.
7. Cats in shock: gray gums, cold, normal or slow heart rate.
8. A blocked male cat is always a stat complaint.
9. On the phone: owner safety, short questions, safe first aid, come in now.
10. No routine home-induced vomiting (RECOVER 2026).
11. Rule of 20: 20 parameters, at least daily, in every critically ill patient.
12. MGCS 3 to 18, low is bad; ATT 0 to 18, high is bad.