TABLE 1 Mean and SD of thermal thresholds determined in six horses at the withers (location A), cranial (location B) and caudal abdominal area (location C), the area over the tuber coxae (location D) and the hind limb dorsal pastern regions (location E) after administration of 0.2 mg/kg morphine and 0.2 mg/kg xylazine diluted to different volumes.
| Time (h) | Location A | Location B | Location C | Location D | Location E | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | |
| 25 mL volume administered | ||||||||||
| 0 | 48.6 | 2.9 | 49.9 | 202 | 47.9 | 1.1 | 47.5 | 2.4 | 47.9 | 3.7 |
| 2 | 49.4 | 1.1 | 49.6 | 2.9 | 47.5 | 0.9 | 51.9 | 3.0 | 55.0 * | 0.6 |
| 4 | 50.7 | 2.9 | 47.9 | 3.7 | 49.8 | 3.2 | 48.6 | 2.9 | 56.0 * | 0.0 |
| 6 | 49.5 | 3.6 | 46.8 | 3.2 | 47.9 | 1.9 | 49.4 | 1.1 | 54.6 * | 1.0 |
| 8 | 49.6 | 4.8 | 47.9 | 1.9 | 48.7 | 2.1 | 50.7 | 2.9 | 54.7 * | 0.8 |
| 10 | 48.0 | 4.5 | 48.7 | 2.1 | 48.8 | 0.7 | 49.5 | 3.6 | 53.9 * | 3.3 |
| 35 mL volume administered | ||||||||||
| 0 | 48.2 | 2.8 | 49.9 | 2.2 | 47.9 | 1.1 | 47.7 | 2.4 | 47.9 | 3.7 |
| 2 | 48.2 | 3.1 | 48.6 | 1.1 | 47.5 | 0.9 | 52.8 * | 2.8 | 55.2 * | 0.4 |
| 4 | 50.0 | 2.7 | 47.0 | 2.7 | 46.8 | 3.2 | 52.9 * | 2.9 | 55.2 * | 0.4 |
| 6 | 49.2 | 4.0 | 47.0 | 3.2 | 47.9 | 1.9 | 52.3 * | 2.3 | 54.9 * | 1.2 |
| 8 | 50.4 | 4.7 | 49.0 | 2.9 | 48.7 | 2.1 | 53.9 * | 1.9 | 54.8 * | 1.0 |
| 10 | 48.5 | 4.6 | 48.0 | 2.2 | 48.0 | 0.7 | 51.2 | 4.5 | 53.9 * | 3.3 |
| 50 mL volume administered | ||||||||||
| 0 | 48.6 | 2.9 | 49.2 | 1.5 | 47.5 | 1.3 | 47.5 | 2.4 | 47.9 | 3.7 |
| 2 | 49.4 | 1.1 | 49.6 | 2.9 | 50.3 | 3.4 | 53.5 * | 1.6 | 55.3 | 0.5 |
| 4 | 50.7 | 2.9 | 47.9 | 3.7 | 51.1 * | 5.3 | 52.3 * | 4.9 | 55.3 * | 0.5 |
| 6 | 49.5 | 3.6 | 46.8 | 3.2 | 51.6 * | 3.3 | 53.6 * | 3.4 | 54.9 * | 1.2 |
| 8 | 49.6 | 4.8 | 47.9 | 1.9 | 52.7 * | 2.6 | 53.2 * | 3.1 | 55.0 * | 1.1 |
| 10 | 48.0 | 4.5 | 48.7 | 2.1 | 50.8 | 2.9 | 54.5 * | 2.9 | 54.9 * | 2.6 |
| 75 mL volume administered | ||||||||||
| 0 | 47.6 | 2.4 | 50.2 | 1.3 | 48.3 | 1.5 | 47.5 | 2.4 | 47.9 | 3.7 |
| 2 | 50.4 | 1.6 | 53.3 * | 3.0 | 54.0 * | 4.0 | 55.5 * | 0.5 | 55.3 * | 0.5 |
| 4 | 50.1 | 2.9 | 51.5 | 5.6 | 54.7 * | 2.3 | 54.5 * | 2.2 | 55.2 * | 0.4 |
| 6 | 48.9 | 3.1 | 50.4 | 6.0 | 54.5 * | 2.7 | 54.3 * | 2.2 | 54.9 * | 1.2 |
| 8 | 46.8 | 2.5 | 51.3 | 4.5 | 54.3 * | 3.1 | 53.9 * | 2.7 | 55.0 * | 2.6 |
| 10 | 47.4 | 4.1 | 52.5 * | 3.7 | 54.3 * | 3.1 | 53.4 * | 4.5 | 54.9 * | 2.6 |
| 100 mL volume administered | ||||||||||
| 0 | 48.1 | 3.0 | 48.5 | 1.4 | 47.9 | 1.1 | 47.5 | 2.4 | 49.0 | 2.3 |
| 2 | 50.8 | 2.5 | 52.9 * | 3.0 | 53.8 * | 4.1 | 55.5 * | 0.5 | 55.3 * | 0.5 |
| 4 | 51.0 * | 3.3 | 52.1 * | 3.3 | 54.5 * | 2.3 | 53.2 * | 5.0 | 55.3 * | 0.5 |
| 6 | 51.0 | 4.0 | 51.9 * | 3.9 | 54.2 * | 2.8 | 54.8 * | 22 | 55.3 * | 0.5 |
| 8 | 51.3 * | 3.4 | 51.5 | 4.3 | 54.2 * | 3.3 | 54.7 * | 2.4 | 55.3 * | 0.5 |
| 10 | 52.2 * | 2.1 | 51.7 | 4.1 | 54.3 * | 3.2 | 54.7 * | 0.5 | 56.0 * | 0.0 |
*
Statistically significant different (P < .05) to the baseline measurements (time 0 hours).