Table 2.
Variable | Criteria | Specificity (%) 1 | Relevance (confidence interval) 2 | Item-total correlation 3 | ||
GA x GC | GAA X GC | GCA x GC | ||||
Positioning in the stall | The horse’s head is at the outside door | 78.3 | 18.6 (4.4-78.9)* | 48.3 (10.0-233.1)* | 0.1 (0–0.4) | 0.4 |
The horse is inside the stall, but looking at the outside door, observing the environment | 19.5 | 0.6 (0.2-2.0) | 0.1 (0.0-0.7) | 1.9 (0.6-6.16) | ||
The horse is eating | 0.9 | NE | NE | NE | ||
The horse is not close to the outside stall door and does not look interested in the environment | 0.9 | NE | NE | NE | ||
Head position | Above the withers or grazing | 95.0 | NE | NE | NE | 0.2 |
At the level of the withers | 3.3 | NE | NE | NE | ||
Below the withers but not eating | 0.0 | NE | NE | NE | ||
Response to opening the door | The horse moves towards the door or is already positioned at the outside door | 15.8 | 1.0 (0.2-3.7) | 1.5 (0.4-6.0) | 1.9 (0.6-6.5) | 0.3 |
The horse looks at the door, but does not move towards the door | 15.8 | 0.7 (0.2-3.3) | 0.3 (0–1.7) | 0.5 (0.1-1.7) | ||
The horse does not respond to opening the door | 1.7 | NE | NE | NE | ||
Response to approach and presence of the observer | Moves towards or looks to the observer | 84.7 | 0.3 (0.1-1.5) | 0.2 (0.1-0.9) | 1.4 (0.3-6.1) | 0.2 |
Moves away from the observer | 2.5 | NE | NE | NE | ||
Does not move | 12.7 | 3.8 (0.8-18.8) | 4.6 (1.0-21.2)* | 0.7 (0.1-3.7) | ||
Appetite for hay | The horse eats hay | 99.1 | NE | NE | NE | 0.2 |
The horse does not eat hay | 0.8 | NE | NE | NE | ||
Response to concentrate food | Moves to the food and eats | 90.7 | NE | NE | NE | 0.2 |
Hesitates to move towards the food, but eats | 8.0 | NE | NE | NE | ||
Shows no interest in food, not eating | 0 | NE | NE | NE | ||
Locomotion | The horse moves freely alone | 84.2 | 47.6 (4.9-464.0)* | 5.8 (1.6-21.3)* | 0.2 (0–0.6) | 0.4 |
The horse does not move, or is reluctant to move | 10.0 | 0 (0–0.2) | 0.2 (0.1-0.7) | 6.2 (1.6-23.2)* | ||
The horse is agitated, restless | 5.8 | NE | NE | NE | ||
Locomotion when led by the evaluator | The horse moves freely when led | 86.5 | 108.2 (4.4- > 999.9)* | 68.1 (4.9-946.5)* | 0 (<0.001-0.1) | 0.4 |
The horse does not move, or is reluctant to move when led | 12.2 | NE | NE | NE | ||
The horse is agitated, restless | 0.0 | NE | NE | NE | ||
Variable | Criteria | Specificity (%) 1 | Relevance (confidence interval) 2 | Item-total correlation 3 | ||
GA x GC | GAA X GC | GCA x GC | ||||
Response to palpation of the painful area (approximately 3 cm besides the wound) | No response or change in relation to pre-procedure palpation response of the surgical wound | 57.1 | 4.1 (1.1-15.)* | 18.8 (4.6-76.0)* | 0.3 (0.1-1.1)* | 0.4 |
Mild reaction to palpation of the surgical wound | 29.4 | 0.1 (0–0.5) | 0.1 (0–0.5) | 1.9 (0.6-5.9)* | ||
Violent reaction to palpation of the surgical wound | 13.4 | 2.1 (0.6-7.8)* | 0.1 (0–1.3)* | 1.7 (0.4-7.5)* | ||
Response to an auditory stimulus (clap hands) | Moves and/or pays attention with ears or head movements | 80.0 | 6.8 (0.5-84.0) | 4.9 (0.7-33.6) | 0.5 (0.1-2.0) | 0.3 |
Calm, no response | 18.6 | NE | NE | NE | ||
No response to auditory stimulus due to prostration | 0.0 | NE | NE | NE | ||
Looking at the flank | The horse does not look at the flank | 84.6 | 46.7 (9.9-219.0)* | 128.9 (21.2-782.7)* | 0.1 (0–0.3)* | 0.4 |
The horse looks at the flank | 15.4 | 0 (0–0.1) | 0 (0–0) | 11.7 (3.1-43.7)* | ||
Kicking at the abdomen | The horse does not kick the abdomen | 95.8 | NE | NE | NE | 0.3 |
The horse kicks at the abdomen | 2.5 | NE | NE | NE | ||
Lifting hind limbs | No lifting of hind limbs | 74.6 | 18.0 (3.9-81.9)* | 96.5 (16.4-566.4)* | 0.1 (0–0.4) | 0.6 |
Lifting hind limbs | 22.0 | 0.2 (0.1-0.8) | 0 (0–0.2) | 4.6 (1.3-16.1)* | ||
Lifting one of the hind limbs and extending the head | 3.4 | NE | NE | NE | ||
Head movement | Head straight ahead most of the time | 87.1 | 91.2 (10.1-822.7)* | 32.4 (6.7-155.7)* | 0.1 (0–0.3) | 0.4 |
Lateral and/or vertical occasional head movements | 12.1 | NE | NE | NE | ||
Lateral and/or vertical continuous head movements | 0.9 | NE | NE | NE | ||
Pawing on the floor (fore limbs) | Quietly standing, no pawing | 89.7 | 17.5 (3.6-84.9)* | 38.9 (6.6-230.1)* | 0.1 (0–0.5) | 0.4 |
Pawing | 9.4 | 0.1 (0–0.4) | 0 (0–0.2) | 4.1 (1.12-14.1)* | ||
Others | Moving the tail sharply and repeatedly | 21.7 | 0.9 (0.2-3.5) | 0.5 (0.1-2.1) | 1.8 (0.5-6.7) | 0.5 |
Moving the tail sharply and repeatedly and lifting the hind limbs | 9.2 | 0 (0–0.2) | 0 (0–0.2) | 2.4 (0.9-6.9) | ||
Partial penis protrusion | 23.2 | 2.3 (0.4-12.5) | 8.5 (1.6-4.2) | 0.4 (0–2.0) | 0.2 | |
Penis protrusion | 47.4 | NE | NE | NE | ||
GA x GC | GAA X GC | GCA x GC | ||||
Heart rate | - | - | - | - | 0.6 | |
Respiratory rate | - | - | - | - | 0.5 | |
Systolic blood pressure | - | - | - | - | 0.4 | |
Digestive sounds | - | - | - | - | 0.3 |
The categories written in bold letters were used for the sum of the total score. NE – not evaluated as there were not sufficient data for statistical analysis (the behaviour was either infrequently or not observed). GA – Anaesthesia only (n = 6). GAA – Pre-emptive analgesia followed by anaesthesia (n = 6). GC – Anaesthesia, castration and postoperative analgesia administered four hours after surgery (n = 6). GCA – Pre-emptive analgesia, followed by anaesthesia and castration (n = 6).
1The specificity of each item was evaluated by investigating if that particular behaviour was present or not at TC, moment without pain, in all observations from all evaluators, in all animals from all groups. Specificity was classified as excellent (0–4.9%), good (5–14.9%), moderate (15–29.9%), or nonspecific (≥30%).
2Relevance was tested based on the possibility of distinguishing the behaviour in T4 in GC compared to the other groups. The item was considered relevant when that item differentiated GC from the other three groups, or when GC was different from animals without pain (GA and GAA). The item was considered irrelevant when there were no differences between GC and the other groups. Asterisks (*) indicate differences between groups.
3Criterion validity for item-total correlation with Pearson correlation test (weak < 0.30; moderate 0.31 – 0.60; strong 0.61 – 0.9; very strong 0.91 -1.0) [8].