Pain Management & Analgesia Free guide

Pain Assessment Scales: Glasgow CMPS-SF, Colorado State and the Feline Grimace Scale

Pain Management/Analgesia (D9 B; K44) 14 min read, 3,201 words Last verified

Learn the pain scales a veterinary technician uses every shift: Glasgow, Colorado State, UNESP-Botucatu and the Feline Grimace Scale, with their score ranges, intervention levels and owner tools for chronic pain.

Introduction

A pain scale is a structured form that turns what you see and feel in a patient into a number. Technicians score patients in recovery, on hospital rounds, after a rescue dose and at recheck visits. The number matters because it tells the team when to treat and whether the treatment worked.

There is no "gold standard" test for pain in animals, and many published scales have never been validated.1 This guide covers the Glasgow, Colorado State University (CSU) and UNESP-Botucatu scales, the Feline Grimace Scale and the owner questionnaires used for chronic pain: what each scores, its range, its intervention level and how to act on the result.

Key facts

  • Glasgow CMPS-SF (dog, acute): 6 categories, maximum 24. Analgesia is indicated at 6/24 or more, or 5/20 or more when mobility cannot be assessed.2
  • Glasgow CMPS-Feline (cat, acute): maximum 20, intervention at 5/20 or more.2
  • Feline Grimace Scale: 5 action units (ear position, orbital tightening, muzzle tension, whiskers, head position), each scored 0, 1 or 2. Rescue analgesia is indicated when the total is above 0.39 out of 1.0.3
  • UNESP-Botucatu multidimensional scale (cat): maximum 30, intervention above 7/30. Its short form (UFEPS-SF) has 4 items, maximum 12, rescue at 4/12 or more.25
  • CSU acute pain scales score 0 (normal) to 4 (severe). They began as teaching tools and have no validated intervention score.26
  • Chronic pain is scored by owners: CBPI and LOAD for dogs with osteoarthritis, FMPI for cats with degenerative joint disease.1611
  • A low score does not rule out pain. If pain is likely, analgesia should be given, and the response to an analgesic is the most accurate test.1

How the VTNE tests this

  • Recognize need for analgesia (Domain 9 Task B; K44 "Pain assessment and analgesic administration techniques").14 Expect "this patient scores X; what do you do next?"
  • Choose the right tool: match species (dog or cat) and pain type (acute or chronic) to a scale, or pick the owner questionnaire for osteoarthritis.
  • Know the numbers: maximum scores and intervention levels for the CMPS-SF, CMPS-Feline, UNESP-Botucatu and Feline Grimace Scale.
  • Calculate: a Feline Grimace Scale total when one action unit cannot be scored, or a CMPS-SF total without the mobility item.
  • Support the plan and educate the client (Domain 9 Task C; Domain 10 Task A, which lists pain assessment and management among client education topics).14

Core concepts

Why scoring beats guessing

Pain is an individual experience with sensory and emotional parts.2 Normal species behavior can mask it, and the signs are often not what people expect. A dog may wag its tail and greet you while in pain. A cat sitting quietly at the back of the cage after surgery may be in pain even though it is not pacing or crying.1 A validated scale gives every observer the same checklist.

Scales based on the presence or absence of species-specific behaviors are likely to be more accurate than generic scales that rely on the observer's interpretation.1 Even so, observers disagree. One study found 29% to 36% variation between veterinarians using simple descriptive, numerical and visual analog scales, and similar variation has been reported for the CMPS-SF.6 Using one scale, the same way, every time reduces that noise.

Why vital signs are not enough

Heart rate, respiratory rate, blood pressure and pupil size can rise with acute pain, particularly under anesthesia. They are not specific: they cannot separate pain from fear, anxiety or metabolic conditions such as anemia, and animals with chronic pain may have normal values.1 Normal vital signs never prove that a patient is comfortable.

Validated, intervention level and terms you need

  • Validated: the scale has been tested to show it measures pain (validity), gives similar results between observers (reliability) and changes after treatment (responsiveness). A 2026 systematic review rated the UNESP-Botucatu scale, its short form and the Feline Grimace Scale as having the highest quality of evidence, and found that dog scales generally had weaker evidence than cat scales.2
  • Intervention level (also called the cut-off or rescue threshold): the score at which analgesia is recommended. Some scales use "this score or more" (CMPS-SF, 6/24 or more) and others use "above this score" (FGS, above 0.39). The CSU scales do not have one.2
  • Clinical metrology instrument (CMI): a questionnaire completed by the owner or caregiver that scores chronic pain or mobility at home.11

Acute pain scales used in hospital

Glasgow CMPS-SF (dog). The short form scores six categories: vocalization, attention to the wound, mobility, response to touch, demeanor and posture/activity. In each category you pick the description that best matches the dog, and the ranked scores are added. The maximum is 24, or 20 if mobility cannot be assessed.6 Analgesia is indicated at 6/24 or more, or 5/20 or more without mobility.2

Glasgow CMPS-Feline (cat). The definitive feline version scores observation, approach and interaction, palpation and a general impression, with a maximum of 20 and an intervention level of 5/20 or more.2 It includes two facial features, the ears and the muzzle.3

CSU acute pain scales (dog and cat). These were first created as educational tools. They are scored on a 0 to 4 scale2 using behavioral signs, response to palpation and body tension.6 The canine scale is listed as not validated, and the feline scale has no defined analgesic intervention score.26

UNESP-Botucatu scales (cat). The multidimensional composite scale was developed using cats after ovariohysterectomy. It scores psychomotor change, protection of the wound, physiologic variables and vocal expression, maximum 30, with intervention above 7/30.2 The short form (UFEPS-SF) scores posture, activity, attitude and reaction to touch and palpation of the painful site, each 0 to 3, for a maximum of 12. Rescue analgesia is given at 4/12 or more.5

Feline Grimace Scale (FGS). The FGS scores five facial action units. Ear position: the ear tips are pulled apart and rotated outward. Orbital tightening: the eyes narrow or squint. Muzzle tension: the muzzle flattens from round to elliptical. Whiskers: they move forward and away from the face. Head position: the head is below the shoulder line or tilted down. Each unit is scored 0 (absent), 1 (moderate or uncertain) or 2 (obvious). The total is the sum divided by the maximum possible, so it runs from 0 to 1.0, and a unit you cannot see is left out of both numbers.3 Rescue analgesia is indicated above 0.39.3 The developers describe it as usable by both veterinary professionals and cat owners.15

Table 1. Common pain scales at a glance
ScaleSpeciesAcute or chronicScoring rangeIntervention levelValidation (who)
Glasgow CMPS-SFDogAcute (postoperative)0 to 24 (0 to 20 without mobility)6/24 or more; 5/20 or moreReid and colleagues, 2007 (Glasgow); listed as partially validated
Glasgow CMPS-FelineCatAcute0 to 205/20 or moreReid and colleagues, 2017 (Glasgow)
CSU Canine and Feline Acute Pain ScalesDog, catAcute0 to 4None definedColorado State University; canine scale not validated, feline scale preliminary data only
UNESP-Botucatu multidimensional scaleCatAcute (postoperative)0 to 30Above 7/30Sao Paulo State University (Unesp) group; high-quality evidence
UNESP-Botucatu short form (UFEPS-SF)CatAcute0 to 124/12 or moreUnesp group; high-quality evidence
Feline Grimace ScaleCatAcute0 to 1.0Above 0.39Universite de Montreal group (Evangelista and colleagues, 2019); high-quality evidence
Canine Brief Pain Inventory (CBPI)DogChronic (osteoarthritis, bone cancer)Each item 0 to 10Not used as a rescue cut-offOwner questionnaire, validated for osteoarthritis and bone cancer
Liverpool Osteoarthritis in Dogs (LOAD)DogChronic (osteoarthritis)13 itemsChange of 4 points is the suggested meaningful differenceOwner questionnaire, University of Liverpool group
Feline Musculoskeletal Pain Index (FMPI)CatChronic (degenerative joint disease)Short form: 9 itemsNot used as a rescue cut-offOwner questionnaire; forms available from North Carolina State University

Sources: Lee and Steagall 20262; Sander 20256; Evangelista 20193; Belli 20215; Merck1; CBPI, LOAD and FMPI papers.891011

Choosing a pain tool by species and pain type ACUTE in hospital, scored by staff CHRONIC at home, scored by owner DOG CAT Glasgow CMPS-SF 6 items, max 24 act at 6/24 (5/20) CSU Canine scale 0 to 4, teaching tool no validated cut-off CBPI severity + interference items scored 0 to 10 LOAD 13 items, osteoarthritis also Helsinki (HCPI) Feline Grimace Scale 5 face units, act > 0.39 Glasgow CMPS-Feline max 20, act at 5/20 UNESP-Botucatu > 7/30; short form 4/12 (CSU Feline: 0 to 4) FMPI short form 9 items MiPSC checklist 6 yes/no screening items CSOM activities chosen for each cat and home
Figure 2. Match the tool to the species and the pain type first. Acute scales are scored by the hospital team and have intervention levels; chronic tools are owner questionnaires that track change over weeks.

Chronic pain tools completed by owners

Chronic pain signs such as less activity, less grooming and a smaller appetite are subtle and not specific, so owner observations are essential.1 The tools below are questionnaires the owner fills in. Your job is to give the same tool each visit, check that it is complete and put the score in the record.

  • Canine Brief Pain Inventory (CBPI): four pain severity items and six pain interference items, each on a 0 to 10 scale, plus one quality of life item. The severity and interference scores are the means of each set.8 It is validated for canine osteoarthritis and bone cancer.1
  • Liverpool Osteoarthritis in Dogs (LOAD): an owner-completed instrument with 13 mobility and activity items.69 Its authors currently recommend a change of 4 points as the minimal clinically important difference.10
  • Feline Musculoskeletal Pain Index (FMPI): the most widely studied cat questionnaire for degenerative joint disease. The short form has nine mobility and daily activity items scored from "normal" to "not at all".11
  • Feline Musculoskeletal Pain Screening Checklist (MiPSC): six yes or no items. Any "no" (activity not normal) should prompt further evaluation.11

Procedure or technique

Scoring an acute pain patient on rounds

  1. Check the order sheet for analgesics given, their times and any rescue order.
  2. Use the hospital's chosen scale for that species, and the same scale for every score in this stay.
  3. Observe from outside the kennel first. Look at posture, activity, facial expression and attention to the wound before you open the door. In the FGS clinical study, cats were watched undisturbed for three minutes before anyone interacted with them, and sedation was scored before pain.4 When the same study scored FGS images, it did not use frames where the cat was sleeping, grooming or vocalizing,4 so score the face when the cat is awake, settled and facing you.
  4. Approach and interact. Call the patient, open the door and note the response. Demeanor is a scored item on composite scales such as the CMPS-SF.6
  5. Touch near the wound or painful area gently when the scale asks for it, and walk the dog if mobility is scored and the patient is allowed to walk. If mobility cannot be assessed, score the CMPS-SF out of 20.6
  6. Add up the score, compare it with the intervention level and follow Figure 1.
  7. Record it. Write the scale name, score out of the maximum, time, your initials and what you did about it.
  8. Re-score after any analgesic, once the drug has had time to act. In one feline study, cats were re-scored 60 minutes after methadone and 90 minutes after dipyrone, timed to each drug's pharmacokinetics.5

How often to score

Your hospital protocol sets the interval. Research protocols show what frequent scoring looks like: in one FGS study cats were scored at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours after extubation,4 and in a UNESP-Botucatu study cats were scored every hour for the first 6 hours after extubation.5 Score more often early after surgery and after every rescue dose. Chronic pain needs frequent reassessment too, because treatment is adjusted over time.7

Table 2. What the technician does at each step of a pain score
StepWhat you doWhy it matters
Before you touchWatch posture, face, activity and wound attention from outside the kennelHandling changes behavior; the FGS is scored on an undisturbed cat
InteractionCall, approach, open the door, note demeanorDemeanor and response to people are scored items
Touch and movementGentle pressure near the wound; walk the dog if allowedResponse to touch and mobility are CMPS-SF categories
ScoreTotal out of the right maximum (24 or 20 for the CMPS-SF)The intervention level depends on the maximum used
ActAt or above the intervention level, notify the veterinarian and give rescue analgesia as orderedTreat pain promptly
Re-scoreAfter the drug has had time to actShows whether the treatment worked
RecordScale, score, maximum, time, initials, actionLets the next shift compare scores

Sources: Evangelista and colleagues 20204; Sander and colleagues 20256; Lee and Steagall 20262; Belli and colleagues 2021.5

Flowchart: score, intervene, re-score

Decision tree: score, intervene, re-score 1. Observe before you touch posture, face, activity, wound attention 2. Score with a validated scale right species, right pain type, same scale each time 3. At or above the intervention level? Tell the vet. Give rescue analgesia as ordered. Re-score once the drug has had time to act. Do behavior or history still suggest pain? Report to the vet. An analgesic trial may be ordered. Record scale, score, time and initials. Re-score at the next scheduled check. A low score never overrides clear signs of pain. Yes No Yes No
Figure 1. The technician's loop. A score at or above the intervention level leads to rescue analgesia as ordered and a re-score. A score below the level is not the end: if behavior or history still suggests pain, report it, because response to an analgesic is the most accurate test of pain.

The second question in the tree matters. The Merck Veterinary Manual states that even when animals score low on pain scales, analgesia should be given if pain is considered likely, and that giving an analgesic and watching the response is the most accurate way to find out whether a patient is in pain.1 In the UNESP-Botucatu validation study, observers gave analgesia to some cats that scored below 4/12 when they felt the cat could be in pain.5

Species differences

Dogs

The Glasgow CMPS-SF is the pain scale used most often in small animal medicine.6 Remember that dog scales overall have weaker validation evidence than cat scales.2 Social dogs may greet you and wag while painful,1 so score every item rather than judging by the greeting. For chronic pain, use the CBPI, LOAD or the Helsinki Chronic Pain Index (HCPI), all completed by the owner.16

Cats

Cats have the best-validated acute tools: the UNESP-Botucatu scales and the FGS.2 A painful cat may simply sit still and quiet.1 The FGS is fast to use,15 is scored by watching the cat without interacting with it, and was not affected by acepromazine and buprenorphine sedation in one study.4 For chronic pain, use the FMPI or the MiPSC screening checklist.11

Horses, food animals and exotics

Grimace scales have also been developed for mice, rats, rabbits, horses, sheep, lambs, piglets and ferrets.1 Physiologic changes are useful in some settings, such as horses with acute colic.1 Flock animals such as sheep may hide pain by staying bunched up in the flock when an observer approaches.1

Calculation

Worked example: Feline Grimace Scale with one action unit you cannot see.

A cat is 2 hours out of surgery. Ears: 1. Orbital tightening: 2. Muzzle tension: 1. Head position: 1. The whiskers are hidden by a bandage, so that unit is "not possible to score".

  1. Sum of the units you scored: 1 + 2 + 1 + 1 = 5 points.
  2. Maximum possible for the units you scored: 4 units x 2 points/unit = 8 points.
  3. FGS total = 5 points / 8 points = 0.625 (points cancel, leaving a number between 0 and 1).
  4. Compare: 0.625 is above 0.39, so rescue analgesia is indicated. Report to the veterinarian and give the ordered drug.3

The developers' own example is 4/10 = 0.4, which is also above 0.39.3 With all five units scored, a raw total of 4 or more out of 10 is above the cut-off.

CMPS-SF without mobility: a dog on strict cage rest scores 5 on the five remaining items. The maximum is 20, and 5/20 meets the intervention level.2 Writing "5" alone looks like a low score out of 24.

Intervention levels as a share of each scale's maximum Where each scale says "treat" CMPS-SFdog, max 24 CMPS-SFno mobility, max 20 CMPS-Felinecat, max 20 UNESP-Botucatucat, max 30 UFEPS-SFcat, max 12 Feline Grimacecat, max 1.0 6/24 5/20 5/20 > 7/30 4/12 > 0.39
Figure 3. Intervention levels drawn to scale on each scale's own maximum (shaded part = treat zone). Most sit at about a quarter to two fifths of the maximum, so a score that looks small can still mean "treat". Always quote a score with its maximum.
  • Handle painful patients with care. Patients with cancer pain may have pronounced wind-up (heightened) pain and should not be handled without a thorough evaluation.7 Observe first and touch last.
  • Stay in your scope. Technicians score, report and give drugs as ordered. Technicians cannot diagnose, but they frequently identify signs of chronic pain in conversations with owners and during routine checks, and they are well placed to run pain monitoring clinics.11 Laws on technician duties vary between countries.11
  • Document every score with the scale name, score and maximum, time, observer and action taken. Because observers vary, a clear record of who scored and with which scale lets the next shift interpret a change.6
  • Use the official forms. Each scale belongs to its developers. Use the current form or app from the developer, not a copy passed around the hospital (see the figure links below for the FGS and the UNESP-Botucatu scales).
  • Coach owners. For chronic pain, ask the owner to complete the same questionnaire each visit and explain that a rising score is a reason to call. Owner observations are essential for spotting subtle chronic pain.1 For cats after discharge, the FGS developers state that it can be used by cat owners as well as veterinary professionals.15
  • Follow current guidance. The WSAVA Global Guidelines for the Recognition, Assessment and Treatment of Pain were updated in 2022 (published in the Journal of Small Animal Practice in 2023) and include protocols for situations such as castration and ovariohysterectomy, degenerative joint disease, and emergency and critical care.1213

Common mistakes and exam traps

  • "Quiet means comfortable." A quiet cat at the back of the cage may be in pain.1
  • Using heart rate as the pain score. Vital signs are not specific for pain and can be normal in chronic pain.1
  • Forgetting the 20-point CMPS-SF. If mobility is not assessed, the maximum is 20 and the intervention level is 5/20.2
  • Giving the CSU scale a cut-off. The CSU scales run 0 to 4 and have no validated intervention score.26
  • Dividing the FGS by 10 when a unit was not scored. Divide by the maximum for the units you actually scored.3
  • Using an acute hospital scale for osteoarthritis at home. Chronic pain is tracked with owner questionnaires such as the CBPI, LOAD or FMPI.111

Quick review

  1. There is no gold standard for pain in animals; use a validated, species-specific scale.
  2. Glasgow CMPS-SF: 6 categories, act at 6/24 or more, or 5/20 or more without mobility.
  3. Glasgow CMPS-Feline: maximum 20, act at 5/20 or more.
  4. UNESP-Botucatu (cat): act above 7/30; short form act at 4/12 or more.
  5. Feline Grimace Scale: 5 action units scored 0 to 2, total 0 to 1.0, act above 0.39.
  6. FGS total = points scored divided by maximum possible for the units scored.
  7. CSU scales: 0 to 4, teaching tools, no validated intervention score.
  8. Cat scales currently have stronger validation evidence than dog scales.
  9. Vital signs are not specific for pain and may be normal in chronic pain.
  10. Chronic pain: CBPI, LOAD and HCPI for dogs; FMPI and MiPSC for cats; completed by owners.
  11. Observe first, then interact, then touch; re-score after every analgesic dose.
  12. A low score does not rule out pain; report it if pain is still likely.

Test yourself

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

Question 1A dog is 3 hours out of spinal surgery and is on strict cage rest, so the mobility item of the Glasgow CMPS-SF is not assessed. The other five items add up to 5. What should the technician do next?

Show answer

Answer: B. Record 5/20, notify the veterinarian and give rescue analgesia as ordered

Without the mobility item the CMPS-SF maximum is 20, and the intervention level is 5/20 or more, so this dog has reached the level for analgesia. A is wrong because 5 is not out of 24 when mobility is skipped. C is wrong because walking a dog on strict cage rest after spinal surgery breaks the activity order; the scale allows a 20-point score for this reason. D is wrong because the CMPS-SF is designed to be scored out of 20 when mobility cannot be assessed.

Source A systematic review of acute pain scoring instruments and their measurement properties in cats and dogs, Table 5, J Vet Intern Med 2026

Question 2A cat is scored with the Feline Grimace Scale. Ear position 1, orbital tightening 2, muzzle tension 1, head position 0. The whiskers cannot be seen because of a nasal bandage. What is the FGS score and what does it mean?

Show answer

Answer: C. 0.50, which is above the cut-off, so report for rescue analgesia

Add the units you scored: 1 + 2 + 1 + 0 = 4 points. The maximum for 4 scored units is 4 x 2 = 8 points. 4/8 = 0.50, which is above the 0.39 cut-off for rescue analgesia. A and B divide by 10 instead of 8; the whiskers unit is left out of both the sum and the maximum. Even 0.40 would be above 0.39, so neither A nor B is a correct reading. D doubles the score by dividing by 5 units instead of the 8-point maximum.

Source Facial expressions of pain in cats: the development and validation of a Feline Grimace Scale, Methods and Discussion, Sci Rep 2019

Question 3The owner of a 13-year-old cat says the cat no longer jumps onto the bed and uses the stairs slowly. The veterinarian asks you to start tracking the cat's joint pain at home over the next few months. Which tool fits this job best?

Show answer

Answer: D. The Feline Musculoskeletal Pain Index completed by the owner

The FMPI is an owner-completed questionnaire for pain linked to degenerative joint disease and is the most widely studied tool of its kind; its short form has nine mobility and daily activity items. A and C are acute pain scales designed for hospital use. B is an acute pain tool based on facial expression and is not designed to track mobility at home over months.

Source Feline chronic pain management: the importance of a team approach for optimal outcomes, Table of tools, J Feline Med Surg 2025

Question 4A new team member asks why the hospital does not use a set rescue cut-off with the Colorado State University (CSU) acute pain scales. Which explanation is accurate?

Show answer

Answer: A. They began as teaching tools scored 0 to 4 and have no validated cut-off

The CSU scales were created as educational tools, are scored from 0 (normal) to 4 (severe) using behavior, response to palpation and body tension, and neither has a validated intervention score: the canine scale is listed as not validated, and the feline scale has no defined intervention score. B is wrong because they are behavior-based, not vital-sign scales. C is wrong because staff score them in hospital. D is wrong because they are canine and feline scales.

Source Assessment of acute and chronic pain in canine internal medicine: what is missing in our diagnostic toolbox?, Table 1, Front Vet Sci 2025

Question 5Four hours after a mastectomy, a cat is crouched at the back of the cage with half-closed eyes and has not touched its food. Its score is just below the intervention level on the hospital's feline scale. What is the best next step?

Show answer

Answer: B. Report the signs to the veterinarian, since an analgesic trial may be needed

A low score does not rule out pain. If pain is considered likely, analgesia should be given, and the response to an analgesic is the most accurate way to tell whether the patient is in pain. A ignores clear signs. C is wrong because vital signs are not specific for pain. D is wrong because painful cats often sit quietly rather than pace or cry.

Source Recognition and Assessment of Pain in Animals, Merck Veterinary Manual

0 of 5 answered

Practise this topic

Two questions from our VTNE practice bank on this topic.

Question 1A dog recovering from tibial fracture repair is scored with the short form Glasgow Composite Measure Pain Scale (CMPS-SF) and scores 7 out of 24. Which action is most appropriate?

Show answer

Answer: C. Give rescue analgesia, since 6 of 24 or more means pain is uncontrolled

The CMPS-SF is linked to a validated intervention level: a score of 6 or more out of 24 (or 5 or more out of 20 when the mobility section is omitted) indicates that additional analgesia is needed. A score of 7 of 24 is above that threshold, so the technician should notify the veterinarian and give the prescribed rescue analgesia, then reassess. Giving an analgesic and watching the response is the most reliable way to confirm that a patient was in pain.

A score of 7 is not within the comfortable range, so routine monitoring alone would leave the dog in pain. The CMPS-SF scores pain behaviors, not sedation, so a high score is not a reason to reduce analgesia. Withholding all analgesics from a dog already above the intervention level is unethical and would only make the pain worse.

Source The Short Form of the Glasgow Composite Measure Pain Scale in Post-operative Analgesia Studies in Dogs: A Scoping Review (Testa B et al., 2021), Frontiers in Veterinary Science (open access)
Recognition and Assessment of Pain in Animals, Merck Veterinary Manual

Question 2A technician is learning to use the Feline Grimace Scale to assess a cat recovering from a urethral obstruction procedure. Which five action units does this scale assess?

Show answer

Answer: B. Orbital tightening, ear position, muzzle tension, whiskers, head position

The Feline Grimace Scale, developed and validated by Evangelista and colleagues in 2019, scores five facial action units: ear position, orbital tightening, muzzle tension, whiskers change and head position. Each is scored 0 to 2, giving a total of 10, and the study set a cut-off for giving analgesia (a total above 0.39 of 1.0, roughly 4 of 10). It is scored from images of the cat sitting undisturbed, and scores fell after analgesic treatment, showing it detects response to analgesia.

Skin twitching, tongue protrusion, eye color and tail position are not part of the scale. Pupil size, nasal discharge, coat condition and breathing pattern are physiologic or general findings, not facial action units. Lip curl, blink rate and nostril flaring are not scored either, although whisker change and ear position are.

Source Facial expressions of pain in cats: the development and validation of a Feline Grimace Scale (Evangelista MC et al., 2019), Scientific Reports (open access)
2022 AAHA Pain Management Guidelines for Dogs and Cats (Gruen ME et al., 2022), American Animal Hospital Association

Practise all 20 questions on this topic Free account. Or try the free practice quiz.

Figure credits

References

  1. Allweiler S. Recognition and Assessment of Pain in Animals. Merck Veterinary Manual, Professional Version. merckvetmanual.com (accessed 2026-10-30) merckvetmanual.com/therapeutics/pain-assessment-and-management/recognition-and-assessment-of-pain-in-animals
  2. Lee J, Steagall PV. A systematic review of acute pain scoring instruments and their measurement properties in cats and dogs. J Vet Intern Med. 2026. PMC12862644 pmc.ncbi.nlm.nih.gov/articles/PMC12862644/
  3. Evangelista MC, Watanabe R, Leung VSY, et al. Facial expressions of pain in cats: the development and validation of a Feline Grimace Scale. Sci Rep. 2019;9:19128. PMC6911058 pmc.ncbi.nlm.nih.gov/articles/PMC6911058/
  4. Evangelista MC, Benito J, Monteiro BP, et al. Clinical applicability of the Feline Grimace Scale: real-time versus image scoring and the influence of sedation and surgery. PeerJ. 2020;8:e8967. PMC7164424 pmc.ncbi.nlm.nih.gov/articles/PMC7164424/
  5. Belli M, de Oliveira AR, de Lima MT, et al. Clinical validation of the short and long UNESP-Botucatu scales for feline pain assessment. PeerJ. 2021;9:e11225. PMC8048399 pmc.ncbi.nlm.nih.gov/articles/PMC8048399/
  6. Sander AN, Storz S, Xenoulis PG, Heilmann RM. Assessment of acute and chronic pain in canine internal medicine: what is missing in our diagnostic toolbox? Front Vet Sci. 2025. PMC12689315 pmc.ncbi.nlm.nih.gov/articles/PMC12689315/
  7. Allweiler S. Chronic Pain in Animals. Merck Veterinary Manual, Professional Version. merckvetmanual.com (accessed 2026-10-30) merckvetmanual.com/therapeutics/pain-assessment-and-management/chronic-pain-in-animals
  8. Wells JR, Young AL, Crane A, et al. Linguistic validation of the Canine Brief Pain Inventory (CBPI) for global use. Front Vet Sci. 2021;8:769112. PMC8666957 pmc.ncbi.nlm.nih.gov/articles/PMC8666957/
  9. Walton MB, Cowderoy E, Lascelles D, Innes JF. Evaluation of construct and criterion validity for the Liverpool Osteoarthritis in Dogs (LOAD) clinical metrology instrument and comparison to two other instruments. PLoS One. 2013;8(3):e58125. PMC3591443 pmc.ncbi.nlm.nih.gov/articles/PMC3591443/
  10. Innes JF, Morton MA, Lascelles BDX. Minimal clinically-important differences for the Liverpool Osteoarthritis in Dogs (LOAD) and the Canine Orthopedic Index (COI) client-reported outcomes measures. PLoS One. 2023. PMC9894389 pmc.ncbi.nlm.nih.gov/articles/PMC9894389/
  11. Monteiro BP, Taylor S, Dowgray N, Eyre K, Gruen M. Feline chronic pain management: the importance of a team approach for optimal outcomes. J Feline Med Surg. 2025. PMC12605920 pmc.ncbi.nlm.nih.gov/articles/PMC12605920/
  12. World Small Animal Veterinary Association. Pain Guidelines. wsava.org (accessed 2026-10-30) wsava.org/global-guidelines/global-pain-council-guidelines/
  13. World Small Animal Veterinary Association Pain Committee. Pediatric patients pain management protocol. wsava.org (accessed 2026-10-30) wsava.org/wp-content/uploads/2024/08/Pediatric-Pain.pdf
  14. American Association of Veterinary State Boards. Veterinary Technician National Examination (VTNE) Content Outline, approved March 2023. aavsb.org (accessed 2026-10-30) aavsb.org/wp-content/uploads/2025/04/AAVSB-2023-Veterinary-Technician-National-Examination-Content-Outline-2.pdf
  15. Feline Grimace Scale. Assess acute pain in cats with scientific precision. felinegrimacescale.com (accessed 2026-10-30) felinegrimacescale.com/

Spotted an error? Email support@vtneexam.com and we will check it against the sources.