Colorado State University Acute Pain Scale: Canine and Feline Versions Explained
The Colorado State University canine and feline acute pain scales explained: each 0 to 4 score, the body map, when to reassess analgesia and how reliable the scale is.
The Colorado State University (CSU) acute pain scales score a dog or cat from 0 (no pain) to 4 (severe pain) by matching the patient to written descriptions of behaviour, response to palpation and body tension, plus a body diagram. There is a separate form for dogs and for cats. A score of 2 or higher prints the instruction "reassess analgesic plan" on both forms.
Quick Reference
- Authors: PW Hellyer, SR Uhrig and NG Robinson, Colorado State University Veterinary Medical Center, 2006.
- Scale: 0 to 4, with a "no score" option when the animal is asleep.
- Three columns: psychological and behavioural signs, response to palpation, body tension.
- Body diagram: mark areas that are tender, warm or tense.
- Score 2, 3 or 4: reassess the analgesic plan.
What the Colorado State University Acute Pain Scale Is
The CSU acute pain scales are one-page forms created at the Colorado State University Veterinary Medical Center. The canine and feline forms are both credited to PW Hellyer, SR Uhrig and NG Robinson, with a 2006 copyright. Each form shows a row for each score from 0 to 4, and each row has descriptions in three columns. You read across the rows and choose the one that best fits what you see.
The forms also include a simple outline of the animal, right and left side, so you can mark where the patient is tender to palpation, warm or tense. That map is useful for a hand-off to the next shift and for showing a change over time.
The scale is quick to learn, which is one reason it is widely used in clinics and teaching hospitals. It is a descriptive scale. It does not add up item scores the way the Glasgow CMPS-SF does.
CSU Canine Acute Pain Scale: Scores 0 to 4
The table summarises the descriptors on the canine form. Use the printed form in practice, since the wording below is condensed.
| Score | Psychological and behavioural | Response to palpation | Body tension |
|---|---|---|---|
| 0 | Comfortable when resting, happy, content, not bothering the wound, interested in surroundings | Nontender at the wound or elsewhere | Minimal |
| 1 | Content to slightly unsettled or restless, distracted easily by surroundings | Reacts by looking around, flinching or whimpering | Mild |
| 2 | Looks uncomfortable at rest, may whimper, cry, lick or rub the wound when unattended, droopy ears, worried facial expression, reluctant to respond when beckoned | Flinches, whimpers, cries, or guards and pulls away | Mild to moderate. Reassess analgesic plan |
| 3 | Unsettled, crying, groaning, biting or chewing the wound when unattended, guards the site by shifting weight or limping, may be unwilling to move | May be subtle (shifting eyes, faster breathing) in a stoic dog, or dramatic (sharp cry, growl, bite or bite threat, pulling away) | Moderate. Reassess analgesic plan |
| 4 | Constantly groaning or screaming when unattended, may bite or chew the wound but unlikely to move, potentially unresponsive to surroundings, difficult to distract from pain | Cries at non-painful palpation (possible allodynia or wind-up), may react aggressively | Moderate to severe, may be rigid. Reassess analgesic plan |
Note the score 3 description for stoic dogs. A dog that is too painful to move may only shift its eyes or breathe faster when you palpate. A quiet dog is not always a comfortable dog.
CSU Feline Acute Pain Scale: Scores 0 to 4
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The feline form follows the same layout but the descriptions reflect how cats show pain. The form itself notes that early signs are often subtle in the hospital and more likely to be noticed by the owner at home.
| Score | Psychological and behavioural | Response to palpation | Body tension |
|---|---|---|---|
| 0 | Content and quiet when unattended, comfortable at rest, interested in surroundings | Not bothered by palpation | Minimal |
| 1 | Subtle signs, withdrawal or change in routine at home, content or slightly unsettled in hospital, less interested in surroundings | May or may not react at the wound | Mild |
| 2 | Decreased responsiveness, seeks solitude, loss of brightness in eyes, curled up or tucked up with head lower than shoulders, rough or fluffed coat, may groom a painful area intensively, decreased appetite | Responds aggressively or tries to escape when the painful area is approached, tolerates attention elsewhere | Mild to moderate. Reassess analgesic plan |
| 3 | Constantly yowling, growling or hissing when unattended, may bite or chew the wound but unlikely to move if left alone | Growls or hisses at non-painful palpation, reacts aggressively, pulls away from any contact | Moderate. Reassess analgesic plan |
| 4 | Prostrate, potentially unresponsive to or unaware of surroundings, difficult to distract from pain, receptive to care (even fractious cats become more tolerant of contact) | May not respond to palpation, may be rigid to avoid painful movement | Moderate to severe. Reassess analgesic plan |
High-yield point
On the feline form, a normally fractious cat that suddenly becomes easy to handle scores 4, not 0. Tolerance of handling can be a sign of severe pain in cats. Expect this as a VTNE distractor.
How to Score a Patient with the CSU Scale
The form does not prescribe a fixed procedure, so the order below is a practical one that keeps handling from changing the behaviour you are trying to record.
- Check whether the animal is asleep. If it is truly sleeping, record "no score" and reassess when it is awake.
- Observe from outside the cage. Read the psychological and behavioural column while the patient is unattended.
- Approach and interact. Call the patient's name and watch how it responds. A dog that is reluctant to respond when beckoned, or a cat that seeks solitude, is moving up the scale.
- Palpate gently. Start away from the wound, then move toward it. Note the response and the body tension.
- Mark the body diagram. Record areas that are tender, warm or tense.
- Choose the row that fits best. If the columns point to different rows, report what you saw in each column to the veterinarian. At 2 or more, follow the "reassess analgesic plan" prompt.
How Reliable Is the CSU Scale?
The CSU forms are practical, but they have less published validation than the Glasgow scales. A 2019 study in the Journal of Feline Medicine and Surgery tested the CSU feline acute pain scale in 68 cats after ovariohysterectomy. Inter-rater reliability was moderate to good when used by anaesthesiologists and anaesthesia residents. The correlation with the Glasgow CMPS-Feline was positive but weak (0.31), which fell short of the authors' target for validity. The authors concluded that the scale needs further refinement and testing.
For the technician, the practical message is this: the CSU scale is a reasonable structured way to describe and track pain, especially when the same person scores the same patient over time. For cats, a validated tool such as the Glasgow CMPS-Feline or the Feline Grimace Scale gives more evidence behind the number. Our guide to feline pain scales covers both.
CSU Scale vs the Glasgow CMPS-SF
| Feature | CSU acute pain scale | Glasgow CMPS-SF (dog) |
|---|---|---|
| Species | Separate dog and cat forms | Dog only (cats use CMPS-Feline) |
| Format | Choose one row, 0 to 4, plus body map | Six items added together, 0 to 24 |
| Action point | 2 or more: reassess analgesic plan | 6/24 or more, or 5/20 without mobility |
| How the action point was set | Printed on the form | Derived in a multicentre clinical study |
Is There a CSU Chronic Pain Scale?
Yes. A separate Colorado State University Canine Chronic Pain Scale, credited to NG Robinson and SL Shaver in 2008, uses the same 0 to 4 layout with columns for behaviour, posture and response to palpation of the affected joint. It is covered in our guide to canine chronic pain scales, along with the owner questionnaires used for osteoarthritis.
What the VTNE Expects You to Know
Pain Management and Analgesia makes up 10 of the 150 scored VTNE items, according to the AAVSB content outline. For the CSU scales, know the 0 to 4 range, the three assessment columns, the body map, the "no score" rule for a sleeping patient, and that a score of 2 or more means the analgesic plan should be reassessed. Also know the species differences: dogs tend to vocalise, guard and limp, while cats hide, hunch, stop grooming or groom one spot, and lose interest in food. See the pain scoring systems overview for how the CSU scale compares with numeric and visual analogue scales.
Related Resources: Pain Scoring Systems Overview · Pain Management Study Guide · Pain Management Practice Questions · Emergency and Critical Care Study Guide
Frequently Asked Questions
What is the Colorado State University canine acute pain scale?
It is a one-page descriptive scale from the CSU Veterinary Medical Center that rates a dog's pain from 0 to 4 using behaviour, response to palpation, body tension and a body diagram.
What CSU pain score needs more analgesia?
Both the canine and feline forms print "reassess analgesic plan" at scores of 2, 3 and 4. Report the score to the veterinarian and follow the treatment orders.
Is there a Colorado State University pain scale for cats?
Yes. The CSU feline acute pain scale uses the same 0 to 4 layout with cat-specific descriptions, such as seeking solitude, a tucked-up posture, a fluffed coat and reduced appetite.
Is the CSU pain scale validated?
The feline version has been tested. Reliability was moderate to good, but its agreement with the Glasgow CMPS-Feline was weak, and the authors called for more refinement. The Glasgow scales have stronger validation evidence.
What does "no score" mean on the CSU scale?
It means the animal is asleep and cannot be evaluated. Record it and reassess when the patient is awake.
Key Takeaways
- CSU acute pain scales run 0 to 4, with separate dog and cat forms.
- Score behaviour, palpation response and body tension, then mark the body map.
- A score of 2 or more means reassess the analgesic plan.
- A suddenly tolerant cat may be in severe pain.
- The feline CSU form has weaker validation than the Glasgow CMPS-Feline.
Practise Pain Assessment Questions
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- Hellyer PW, Uhrig SR, Robinson NG. Colorado State University Veterinary Medical Center Canine Acute Pain Scale. 2006. Form (PDF) and CSU Veterinary Teaching Hospital page
- Hellyer PW, Uhrig SR, Robinson NG. Colorado State University Veterinary Medical Center Feline Acute Pain Scale. 2006. Form (PDF)
- Shipley H, Guedes A, Graham L, Goudie-DeAngelis E, Wendt-Hornickle E. Preliminary appraisal of the reliability and validity of the Colorado State University Feline Acute Pain Scale. Journal of Feline Medicine and Surgery. 2019;21(4):335-339. doi.org/10.1177/1098612X18777506
- Reid J, Nolan AM, Hughes JML, et al. Development of the short-form Glasgow Composite Measure Pain Scale (CMPS-SF) and derivation of an analgesic intervention score. Animal Welfare. 2007;16(S):97-104. doi.org/10.1017/S096272860003178X
- Gruen ME, Lascelles BDX, Colleran E, et al. 2022 AAHA Pain Management Guidelines for Dogs and Cats. JAAHA. 2022;58(2):55-76. doi.org/10.5326/JAAHA-MS-7292
- AAVSB. VTNE Candidate Information Handbook. aavsb.org