Large Animal Nursing Care Free guide

Equine Handling, Restraint and Physical Examination

Large Animal (D5 B, I, J; K28, K29, K32) 15 min read, 3,275 words Last verified

Handle, restrain and examine a horse safely: approach and leading, quick-release ties, twitch and stocks, sourced adult TPR values, gut sounds, hydration and a colic triage flowchart.

Introduction

Horses are large prey animals. A frightened 500 kg horse can strike, kick, rear or run through a person before anyone reacts. Most of the work a veterinary technician does with horses starts with safe handling: catching and haltering, leading, tying, lifting feet and holding the horse for the veterinarian. The same technician then takes the TPR (temperature, pulse and respiration), checks the gums and hydration, listens to the gut and spots the early signs of colic (abdominal pain). This guide covers those skills in the order you use them in the barn, with sourced normal values and the restraint tools the VTNE expects you to know.

Key facts

  • Approach, halter and lead from the horse's left side, called the near side. Never approach from directly behind.1011
  • Tie a horse only with a quick-release knot, to a solid fixed object, so it can be freed at once in an emergency.1112
  • Horses have two blind spots: about 3 to 4 feet in front of the face, and directly behind the head extending over the back.10
  • Adult horse resting values: heart rate 28 to 40 beats/min; respiratory rate 10 to 14 breaths/min; rectal temperature 37.3 to 38.2 °C (99.1 to 100.8 °F) for a mare and 37.2 to 38.1 °C (99.0 to 100.6 °F) for a stallion.123
  • Normal capillary refill time (CRT) in a horse is about 1.5 seconds.4
  • A nose twitch takes about 3 to 5 minutes to produce its calming effect, and the effect takes 10 to 15 minutes to wear off after removal.10
  • Heart rate rises with pain, hemoconcentration and low blood pressure, so a high or rising heart rate in a colic patient is a warning sign. A normal heart rate does not rule out a surgical problem.4
  • Horses cannot vomit, so a stomach full of gas or fluid can rupture. Passing a nasogastric tube can save the horse's life.4

How the VTNE tests this

  • Choose the restraint for a procedure and a horse's temperament (Domain 5 Task J, restrain the patient with or without equipment following safety protocols; K32 Safe animal handling and restraint techniques).17
  • Recognize behavior: what ears, tail, stance and a raised hind foot are telling you (Domain 5 Task I; K29 Principles of animal behavior).17
  • Interpret a value: is this heart rate, respiratory rate, temperature or CRT normal for an adult horse (Domain 5 Task B; K28 Animal assessment and monitoring techniques).17
  • Recognize colic and pick the right next step, such as alerting the veterinarian or preparing for a nasogastric tube.
  • Calculate a per-minute rate from a short count, or a fluid deficit from a dehydration estimate.

Core concepts

How a horse sees and reacts

Horses are prey animals with a strong fight-or-flight response. They startle at quick movements and loud noises, and they are calmer when they can see other horses. They also read the handler: a nervous, hesitant person makes a horse more nervous. Often very little restraint is needed, and a soothing voice does a lot of the work.10

A horse sees almost all the way around itself. Monocular vision (one eye at a time) covers about 285°, and binocular vision (both eyes together) covers about 65°. The blind spots are a short zone just in front of the face and a zone directly behind, over the back and hindquarters.10 A person who appears suddenly from a blind spot can startle the horse,12 which is why you speak to the horse before you touch it and approach at an angle toward the shoulder.

How horses injure people

A horse can strike with a front foot, kick straight back, kick out sideways (a "cow kick"), bite, rear, or swing its head or body into you.10 The safest places to stand are close to the shoulder or close to the body. A kick or strike gains force over distance, so a horse that connects with someone standing right beside it does less damage than one that connects at full extension.1112 Figure 1 shows the zones.

Top view of a horse showing blind spots, strike and kick zones, and the safe working position at the left shoulder Blind spot 3 to 4 ft in front Strike zone (front feet) Blind spot and kick zone Cow-kick arc Cow-kick arc Safe: handler at left (near) shoulder same side as the vet Right side = off side Horse, top view
Figure 1. Safe and unsafe zones around a standing horse. Stand close to the left shoulder, on the same side as the person doing the procedure. Avoid the blind spots in front of the face and behind the horse, the strike zone in front, and the kick arcs behind and to the sides.

Normal values in the adult horse

Horses have much slower heart and breathing rates than dogs and cats. A technician who carries small animal numbers into the barn will call a normal horse sick, or miss a sick one.

Table 1. Physical exam values for the adult horse
ParameterNormal valueTechnician note
Rectal temperatureMare 37.3 to 38.2 °C (99.1 to 100.8 °F); stallion 37.2 to 38.1 °C (99.0 to 100.6 °F)Above 40.5 °C (104.9 °F) means overheating
Heart rate28 to 40 beats/minRises with pain, dehydration and low blood pressure
Respiratory rate10 to 14 breaths/minRises with pain, fever, acidosis or lung disease
Capillary refill timeAbout 1.5 secondsProlonged as shock develops
Mucous membranesPink and moistPale, blue, red, grey or dry are abnormal
Pulse siteFacial arteryFemoral artery is used in dogs and cats instead
Newborn foal heart rateAt least about 60 beats/minShould rise quickly after birth

Sources: Merck Veterinary Manual reference guides for rectal temperature, resting heart rates and resting respiratory rates; Merck colic overview, colic examination table, heart disease diagnosis and emergency care for horses.12346916

Two rhythm points surprise students. A second-degree atrioventricular (AV) block can be a normal finding in a resting horse,16 so a dropped beat on auscultation is noted and reported, not treated as an emergency by itself. And because the horse's heart rate is so low, a short count multiplied up carries a large error, so count for longer rather than multiplying up a very short count when you can.

Procedure or technique

Catching and haltering

  1. Check the halter first. All straps fasten from the near side, and the lead rope clips to the ring under the chin. Make sure no rope drags on the ground.11
  2. Speak to the horse. Approach calmly from the front and a little to the side, preferably the near side, toward the shoulder.1112
  3. Loop the lead rope over the neck so you have control, slide the noseband over the nose, then pass the crownpiece over the poll behind the ears and buckle it.1011
  4. Check the fit. The noseband sits just below the cheekbone (zygomatic arch), not low over the soft nostrils.11

Leading

  1. Stand at the left shoulder, facing forward. Hold the lead in your right hand about 20 to 30 cm (8 to 12 inches) from the chin, with the rest folded in your left hand.11
  2. Never wrap the lead rope around your hand, arm or any part of your body. A horse that bolts can drag you.1012
  3. Turn the horse away from you where possible, so you stay on the outside of the turn.11

Tying with a quick-release knot

  1. Tie only to a solid, fixed structure such as a well-built post or ring. Never tie to anything that can move.11
  2. Tie through something strong but breakable, such as baling twine, so a panicking horse breaks the twine instead of the halter, the post or its neck.11
  3. Leave about 45 cm (18 inches) of rope between the tie point and the head. A longer rope lets the horse get a leg over it or its head under it.11
  4. To free the horse, pull the free end of the rope. Never tie with the lead attached to a chain shank or a rearing bit.11

Lifting the feet

  1. Front foot: stand at the shoulder facing the tail, feet beside the horse. Run your hand down the back of the leg to the fetlock, squeeze the fetlock and lean gently into the horse with your shoulder. Support the hoof at the pastern when it comes up.11
  2. Hind foot: stand beside the horse facing the tail, run the hand farther from the horse across the back, down the hamstrings and down the back of the leg to the fetlock, and gently bring the foot forward toward you. When the horse settles, walk the leg back and rest it against the outside of your thighs, keeping hold of the fetlock and pastern.11
  3. Put the foot down gently. Do not drop it, and step away when it is down.

Holding the horse for the veterinarian

  • Stand beside the head on the same side as the person doing the procedure.1011
  • Watch both the horse and the examiner. Never stand directly in front of the horse, never sit or squat near it, and do not let it graze during an exam.11
  • For a horse that keeps cow kicking, one tactic is to hold up the near front leg so the horse is less able to kick on that side. Stay on the same side as the lifted leg, because some horses can still kick diagonally.12

Restraint tools

Restraint carries a welfare cost, so use the least restraint that lets the job be done safely.11 One university standard operating procedure (SOP) ranks physical restraint from least to most severe as: halter, snaffle bit, rearing bit, chain shank, skin twitch, ear twitch, nose twitch.11

Table 2. Equine restraint methods: use and cautions
MethodTypical useCaution
Halter and lead ropeBasic control for most exams and vaccinesNever wrap the rope around your hand
Chain shank (lead chain over or under the nose)More control when leading or handlingNever tie a horse by the chain
Skin twitch (hand hold of neck or shoulder skin)Short distraction for a quick procedureShort term only
Nose (lip) twitch, rope loop or "humane" clampBrief, mildly aversive proceduresHalter first; ask if the horse has been twitched before; keep a hand on it
Ear twitchListed as an alternative restraintOne SOP limits it to very young horses
Stocks (stanchion)Rectal exams, palpation, wound careHorses may try to jump out or go down; use quick-release ties
Chemical restraint (sedation)When physical restraint is not enoughOnly under the veterinarian's direction

Sources: Virginia Tech equine restraint SOP; University of Queensland horse handling SOP; O'Brien and colleagues 2026.101114

The nose twitch

A twitch is a loop of rope or chain on a wooden handle, or a metal plier-like clamp (the "humane twitch"), placed on the upper lip.10

  1. Halter the horse first. Ask the owner whether the horse has been twitched before.1011
  2. Standing on the near side, slip your left hand through the loop, run it down the bridge of the nose, grasp the upper lip firmly and slide the loop onto the lip.10
  3. Twist the handle until the loop is firm but not excessive. Rotate clockwise when on the left side, which makes it less likely to slip off.10
  4. Hold the handle and the lead together, stay close at the shoulder on the same side as the veterinarian, and keep a firm grip. A loose handle becomes a weapon. Warn everyone at once if the twitch comes off.10
  5. Keep it on only briefly. The UQ SOP allows 5 minutes at most before a break.11

Why a twitch works is still debated. The leading idea is that lip pressure releases endorphins (the body's own opioids), producing a sedative and pain-reducing effect, with droopy lips, glassy eyes and a lowered head.1015 Studies report beta-endorphin peaking around 5 minutes, and prolonged twitching has been linked to restlessness and aversive behavior after that early quiet phase.15 Horses also differ: a 2026 trial in 12 horses found strong individual preferences and no overall difference in efficacy between nose twitch, ear hold, a commercial head device and halter alone.14 Read the individual horse.

Stocks and tail wrap

Stocks are a rectangular frame of posts and bars that hold a standing horse. They suit rectal exams, palpation and wound treatment. Tie the halter to the stock ring with a quick-release knot, and remember that a horse may try to jump out or go down.10 For a rectal exam, wrap the tail first to keep tail hair out of the way: start high under the tail, wrap firmly but not too tight, and continue to the end of the dock.11

Physical exam and gut sounds

  1. Observe from a distance first: attitude, stance, breathing, sweating, manure in the stall.
  2. Take the heart rate with a stethoscope or feel the pulse at the facial artery, the usual pulse site in horses.16 Count the respiratory rate while the horse stands quietly.
  3. Take the rectal temperature standing to one side of the hindquarters, never squatting behind the horse.11
  4. Check mucous membrane color, moistness and CRT.4
  5. Listen to the abdomen over several areas on both sides: the cecum on the right, the small intestine high on the left, and the large colon lower on both sides.4 This guide records them as four areas, upper and lower on each side (Figure 2).
  6. Record each finding with units, the time and the side.
Abdominal auscultation areas in the horse, left and right sides Left side (near) Right side (off) Upper left small intestine Lower left large colon Upper right cecum Lower right large colon Record each area: normal, increased, decreased or absent.
Figure 2. Where to listen for gut sounds (borborygmi). Each side is split into an upper and a lower area. Merck places the cecum on the right, small intestine high on the left and the large colon lower on both sides. A complete lack of sounds is usually linked to stalled gut movement (ileus) or poor blood supply.

Hydration

Dehydration in an adult horse is estimated from several signs together, not one. In Merck's table, a horse about 6% dehydrated has a heart rate of 40 to 60, CRT of 2 seconds, moist membranes and a skin tent that returns in 2 seconds. At about 8% the heart rate is 61 to 80, CRT 3 seconds and the membranes tacky. At about 10% the heart rate is 81 to 100, the eyes are visibly sunken, membranes are dry and CRT is 4 seconds. At 12% the heart rate is over 100, the sunken eyes are obvious and CRT is over 4 seconds.7 Packed cell volume (PCV) and total protein also climb as water is lost.7

Flowchart: colic signs triage

Colic means abdominal pain, not one disease. Common signs are pawing with a front foot, looking back at the flank, curling the upper lip, kicking at the belly, lying down, rolling, sweating, stretching as if to urinate, straining, a distended belly, poor appetite, depression and less manure. Few horses show all of them, and the signs do not tell you which part of the gut is involved or whether surgery is needed.4 Your job is to keep people safe, gather numbers fast and get them to the veterinarian.

Decision tree for a technician who sees colic signs in a horse Colic signs seen pawing, flank watching, rolling, sweating Is the horse rolling or thrashing so that people could be hurt? Yes No Stay out of the stall, alert the veterinarian now; keep people clear Record HR, RR, temperature, membrane color, CRT, gut sounds in 4 areas, manure and when signs started Any red flag? HR high or rising, gums pale, blue, red or grey, CRT over 2 s, gut sounds absent Yes No Alert the veterinarian now. Set out nasogastric tube, bucket and stethoscope; recheck vitals often Report findings to the veterinarian. Recheck vitals at the interval ordered; report any change at once
Figure 3. Colic signs triage for the technician. Every colic is reported to the veterinarian; the tree decides how fast and what to set up. It ends in actions, not a diagnosis, because a normal heart rate does not rule out a problem that needs surgery.

When the veterinarian arrives, expect the colic workup to include heart and respiratory rates, mucous membranes, a nasogastric tube, abdominal auscultation, a rectal exam, abdominal fluid sampling (abdominocentesis) and often ultrasound.6 Note the volume and color of any fluid that comes back up the tube (reflux). Less than 1 L is common in a healthy horse.4 Gather the history the veterinarian will ask for: deworming dates and drugs, last dental float, any change in feed or water, cribbing, and whether the horse was resting or working when the signs began.5

Species differences

  • Dog and cat: much faster resting rates (dog heart rate 70 to 120, cat 120 to 140 beats/min) and the pulse is felt at the femoral artery, not the facial artery.216 Small animals can vomit; horses cannot.4
  • Horse: kicks backward and sideways and strikes forward.1012 A horse cannot lie down for long safely, so problems that are minor in other animals can become emergencies.9
  • Foal: a healthy newborn should breathe within 1 minute, stand within 1 hour, nurse within 2 hours and pass its first manure within about 3 hours.9
  • Cattle: cattle are also restrained with halters and quick-release halter ties, and a tail tie can tie the tail to a leg or the neck.13 Cattle handling has its own guide.

Calculation

Example 1: heart rate from a short count. You count 9 beats in 15 seconds.

9 beats / 15 s × 60 s/min = 36 beats/min. This sits inside the adult range of 28 to 40.2

Example 2: fluid deficit. A 500 kg horse is judged 8% dehydrated (heart rate 70, CRT 3 seconds, tacky gums).7 Merck's formula is fluid deficit = % dehydration × body weight (kg).8

0.08 × 500 kg = 40 kg of water. Because 1 kg of water is about 1 L, the deficit is about 40 L.

Maintenance is added on top: 50 mL/kg/24 h × 500 kg = 25,000 mL = 25 L per day.8 The veterinarian sets the plan; you check the math.

  • Wear sturdy boots, ideally steel-toed, and gloves when handling ropes.10
  • Walk around a horse, not under it, and do not duck under cross-ties; unclip one side instead.12
  • When turning a horse out, lead it about 10 m inside the gate, turn it to face the gate, then release it and walk briskly away.1112
  • Sedation is given only on the veterinarian's order.10
  • Teach owners the colic signs and to call the veterinarian early. Ask them to note when the signs started, whether manure has been passed and any recent change in feed or water. A horse in pain is dangerous to handle, so they should keep themselves safe.59
  • Teach owners the normal TPR for an adult horse so they can report numbers when they call.

Common mistakes and exam traps

  • Calling 36 beats/min "bradycardia". It is normal for an adult horse.
  • Choosing "stand in front of the horse to control the head". Never stand directly in front; stand at the shoulder on the vet's side.
  • Choosing a fixed knot "so the horse cannot get loose". The correct answer is a quick-release knot.
  • Thinking a normal heart rate means the colic is mild. Surgical lesions can have a normal heart rate.
  • Leaving a twitch on for a long procedure. Twitching is for brief procedures; prolonged use can make the horse restless.
  • Expecting a horse to vomit. Horses cannot, which is why the nasogastric tube matters.

Quick review

  1. Approach, halter and lead from the near (left) side, at an angle toward the shoulder.
  2. Blind spots: 3 to 4 feet in front of the face and directly behind.
  3. Never wrap a lead rope around any part of your body.
  4. Tie only with a quick-release knot to a fixed object, through breakable twine.
  5. The handler stands on the same side as the person doing the procedure.
  6. Adult horse: HR 28 to 40, RR 10 to 14, temperature about 37.2 to 38.2 °C.
  7. Normal CRT is about 1.5 seconds; pulse is taken at the facial artery.
  8. Nose twitch: about 3 to 5 minutes to work; 10 to 15 minutes to wear off.
  9. Stocks: tie with a quick-release knot; horses may jump or go down.
  10. Listen to gut sounds in 4 areas, upper and lower on each side.
  11. Colic signs: pawing, flank watching, rolling, sweating, less manure.
  12. Fluid deficit (L) = % dehydration × body weight (kg).

Test yourself

5 questions written for this guide. Pick an answer, then check it.

Question 1A technician is asked to hold a horse while the veterinarian cleans a wound on the horse's left forelimb. Where should the technician stand?

Show answer

Answer: C. At the left side of the head, on the same side as the veterinarian

The handler stands beside the head on the same side as the person doing the procedure and watches both the horse and the examiner. A is wrong because you should never stand directly in front of a horse, which is in the strike zone. B is wrong because the handler should be on the same side as the veterinarian, not the opposite side. D is wrong because a long lead gives little control and puts the handler away from the head.

Source EQU_020 Horse Handling, Husbandry, and Minor Procedures, Positioning a Handler, University of Queensland

Question 2A technician records these resting values on a calm adult gelding: heart rate 36 beats/min, respiratory rate 12 breaths/min, rectal temperature 37.8 °C. How should these be reported?

Show answer

Answer: A. All three values are within normal limits for an adult horse

Merck gives adult horse resting heart rate as 28 to 40 beats/min, respiratory rate 10 to 14 breaths/min, and rectal temperature about 37.2 to 38.2 °C. All three values fit. B applies small animal heart rates to a horse. C is wrong because 12 sits inside 10 to 14. D is wrong because 37.8 °C is inside the normal range.

Source Resting Heart Rates, reference guide, Merck Veterinary Manual

Question 3A nose twitch has been applied to a haltered horse for a short procedure. About how long after application should the technician expect the calming effect to appear?

Show answer

Answer: B. About 3 to 5 minutes after the twitch is applied

The Virginia Tech SOP states it may take 3 to 5 minutes for endorphins to produce a sedative effect, and 10 to 15 minutes for the effect to wear off after removal. A is too fast. C is too slow, and a twitch should not be left on that long. D confuses onset with the wearing-off period.

Source SOP: Equine Restraint Techniques, Twitching restraint, Virginia Tech Office of the University Veterinarian

Question 4A 450 kg horse with colic is estimated by the veterinarian to be 6% dehydrated. Using fluid deficit = % dehydration × body weight (kg), what is the deficit?

Show answer

Answer: B. 27 L

0.06 × 450 kg = 27 kg of water, which is about 27 L. A divides weight by 60 instead of multiplying by 0.06. C uses 10% instead of 6%. D multiplies by 6 and then by 0.1, a decimal-place error.

Source Table: Fluid Needs in Dehydrated Horses, Merck Veterinary Manual

Question 5A boarder calls the clinic because her horse is pawing, looking at its flank and lying down. On arrival the technician finds a heart rate of 64 beats/min, grey mucous membranes and no gut sounds on either side. What should the technician do next?

Show answer

Answer: D. Alert the veterinarian now and set out a nasogastric tube

A heart rate well above 28 to 40, grey membranes (poor tissue blood flow) and absent gut sounds (linked to ileus or ischemia) are red flags, so the veterinarian needs to know now, and a stomach tube may be needed because horses cannot vomit. A delays care. B is wrong because drugs are given only on the veterinarian's order and can mask worsening signs. C adds feed to a gut that may be blocked.

Source Overview of Colic in Horses, Clinical evaluation, Merck Veterinary Manual

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Figure credits

  • Figure 1 Original diagram, VTNE Exam Prep
  • Figure 2 Original diagram, VTNE Exam Prep
  • Figure 3 Original diagram, VTNE Exam Prep

References

  1. Merck Veterinary Manual. Normal Rectal Temperature Ranges (reference guide). merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/normal-rectal-temperature-ranges
  2. Merck Veterinary Manual. Resting Heart Rates (reference guide). merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/resting-heart-rates
  3. Merck Veterinary Manual. Resting Respiratory Rates (reference guide). merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/resting-respiratory-rates
  4. Merck Veterinary Manual. Overview of Colic in Horses. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/digestive-system/colic-in-horses/overview-of-colic-in-horses
  5. Merck Veterinary Manual, Horse Owners. Colic in Horses. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/horse-owners/digestive-disorders-of-horses/colic-in-horses
  6. Merck Veterinary Manual. Table: The Veterinarian's Examination of a Horse with Colic. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/multimedia/table/the-veterinarians-examination-of-a-horse-with-colic
  7. Merck Veterinary Manual. Table: Physical and Laboratory Parameters to Estimate Dehydration in Adult Horses. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/multimedia/table/physical-and-laboratory-parameters-to-estimate-dehydration-in-adult-horses
  8. Merck Veterinary Manual. Table: Fluid Needs in Dehydrated Horses. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/multimedia/table/fluid-needs-in-dehydrated-horses
  9. Merck Veterinary Manual, Special Pet Topics. Emergency Care for Horses. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/special-pet-topics/emergencies/emergency-care-for-horses
  10. Virginia Tech Office of the University Veterinarian. SOP: Equine Restraint Techniques. research.vt.edu (accessed 2026-10-31) research.vt.edu/content/dam/ouv_vt_edu/sops/large-animal/sop-equine-restraint.pdf
  11. University of Queensland Animal Ethics Committee. SOP EQU_020 Horse Handling, Husbandry, and Minor Procedures. research-support.uq.edu.au (accessed 2026-10-31) research-support.uq.edu.au/files/66670/EQU_020%20Horse%20Handling%2C%20Husbandry%2C%20and%20Minor%20Procedures.pdf
  12. University of Nebraska-Lincoln Environmental Health and Safety. Safe Operating Procedure: Horse Safety. ehs.unl.edu (accessed 2026-10-31) ehs.unl.edu/sites/unl.edu.business-and-finance.university-operations.ehs/files/media/file/s-horse_safety.pdf
  13. University of Guelph, Ontario Veterinary College. Laboratory Objectives: Bovine and Equine Restraint (Clinical Medicine 1 Lab Manual: Large Animal). books.lib.uoguelph.ca (accessed 2026-10-31) books.lib.uoguelph.ca/app/uploads/sites/52/2020/07/Laboratory-Objectives-Bovine-and-Equine-Restraint.pdf
  14. O'Brien C, Simon O, Franklin SH, et al. Efficacy and welfare effects of different forms of physical restraint for upper airway endoscopy of horses. Equine Vet J. 2026. https://pmc.ncbi.nlm.nih.gov/articles/PMC13244173/
  15. Blum S, Gisler J, Dalla Costa E, et al. Investigating conditioned pain modulation in horses: can the lip-twitch be used as a conditioning stimulus? Front Pain Res (Lausanne). 2024;5:1463688. https://pmc.ncbi.nlm.nih.gov/articles/PMC11540819/
  16. Merck Veterinary Manual. Diagnosis of Heart Disease in Animals. merckvetmanual.com (accessed 2026-10-31) merckvetmanual.com/circulatory-system/diagnosis-of-heart-disease/diagnosis-of-heart-disease-in-animals
  17. AAVSB. Veterinary Technician National Examination (VTNE) Content Outline, approved March 2023. aavsb.org (accessed 2026-10-31) aavsb.org/wp-content/uploads/2025/04/AAVSB-2023-Veterinary-Technician-National-Examination-Content-Outline-2.pdf

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