Optimal lameness induction model development using amphotericin B in meat goats.

Lameness continues to be a critical health and welfare concern associated with goat production. Amphotericin B (amp B) is an antimicrobial successful in inducing transient lameness for research purposes previously in livestock animals. The objectives of this study were to (1) identify which of three varying doses of amp B would be most effective in inducing lameness in meat type goats and (2) develop a facial grimace scale for goats. Lameness was produced by an intra-articular injection of amphotericin B into the left hind lateral claw distal interphalangeal joint with either a 5 mg/0.25 mL (high-low, 5 mg of amphotericin B in a volume of 0.25 mL), 5 mg/0.5 mL (high-high, 5 mg of amphotericin B in a volume of 0.5 mL), or a 2.5 mg/0.25 mL (low-low, 2.5 mg of amphotericin B in a volume of 0.25 mL). A saline treatment of 0.5 mL was used as control (0.9% sterile saline solution). Lameness response was analyzed by infrared thermography (IRT) at the induced joint, mechanical-nociception threshold (MNT), visual lameness scoring (VLS), a visual analogue scale (VAS), kinetic gait analysis (KGA), plasma cortisol (CORT), substance P (Sub P), and behavior scoring. The IRT and MNT values differed by timepoint (P ≤ 0.0001). Results from VLS showed the HL treatment was the most effective at inducing lameness (6/6 goats became lame compared to HH 4/6 and LL 2/6). At 24, 48, and 72 h, VAS scores were significantly higher when comparing HL to all other treatment groups (P = 0.0003). Both behavior observers (1 and 2) reported a significant time effect (P = 0.05), with goats exhibiting more facial grimacing at 24 h post-lameness induction. From these data, an optimal dose for a repeatable lameness induction model in goats was aquired. An effective Goat Grimace Scale (GGS) was also developed to evaluate pain responses in goats.

The Application of 3D Landmark-Based Geometric Morphometrics towards Refinement of the Piglet Grimace Scale.

Proper methods of assessment to objectively identify pain are essential for welfare improvements of piglets undergoing surgical castration on commercial farms. The Piglet Grimace Scale (PGS) is used to identify changes in facial expressions caused by acute pain in piglets undergoing tail docking and castration. However, subjective scoring methods are a concern for the validation of the PGS. The objectives of this study were to evaluate and refine the PGS through 3D landmark geometric morphometrics. Male piglets (n = 88) were randomly allocated to one of two treatments: castration and sham-castration. Piglet facial images were taken at four time points (before treatment, immediately post-treatment, 1 h post-treatment, and 4 h post-treatment) using a photogrammetry rig. Images were scored by four raters using five facial action units (FAUs): orbital tightening, ear position, temporal tension, lip contraction, and nose bulge/cheek tension. Three-dimensional facial models were generated and landmarked denoting 3 FAUs (orbital tightening, lip contraction, and nose bulge/cheek tension). Results suggest that orbital tightening and ear position may be reliable FAUs for the PGS. However, neither the PGS nor 3D landmark-based geometric morphometrics were able (both p > 0.10) to reliably identify facial indicators of pain in piglets undergoing castration.

Effect of bupivacaine liposome suspension administered as a local anesthetic block on indicators of pain and distress during and after surgical castration in dairy calves.

Castration is a routine procedure performed on beef and dairy operations in the United States. All methods of castration cause behavioral, physiologic, and neuroendocrine changes associated with pain. The American Veterinary Medical Association and the American Association of Bovine Practitioners recommend that anesthesia and analgesia be administered during castration. The objective of this study was to evaluate the effectiveness of bupivacaine liposome suspension, a novel, long-acting, local anesthetic formulation administered as a nerve block at castration. The authors chose to investigate this novel formulation as an alternative to the current industry standards using lidocaine nerve blocks alone or in combination with meloxicam. Thirty male Holstein calves, 16 to 20 wk of age, were enrolled and randomly assigned to one of the four treatment groups prior to surgical castration: 1) bupivacaine liposome suspension block + oral placebo (BUP), 2) lidocaine block + oral placebo (LID), 3) lidocaine block + oral meloxicam (1 mg/kg) (LID + MEL), and 4) saline block + oral placebo (CON). Biomarkers were collected at -24 h and from 0 to 120 h post-castration and included infrared thermography, pressure mat gait analysis, chute defense and behavior scoring (pain and activity), and blood sampling for serum cortisol and prostaglandin E2 metabolites (PGEMs). Responses were analyzed using repeated measures, with calf nested in treatment as a random effect, and treatment, time, and their interaction designated as fixed effects. The results from pressure mat gait analysis show that the CON had a shorter front limb stance time from baseline (-8.73%; 95% confidence interval [CI]: -24.84% to 7.37%) compared with BUP and LID + MEL (>5.70%; 95% CI: -22.91% to 23.79%) (P < 0.03). The CON tended to have an increase in front limb force from baseline (6.31%; 95% CI: -1.79% to 14.41%) compared with BUP, LID, and LID + MEL (<-5.06%; 95% CI: -14.22% to 0.95%) (P < 0.04). The CON displayed higher counts of hunched standing (2.00; 95% CI: 1.68 to 2.32) compared with LID + MEL (1.43; 95% CI: 1.13 to 1.72) (P = 0.05). The CON had higher cortisol concentrations at 24 h (7.70 ng/mL; 95% CI: 1.52 to 13.87 ng/mL) relative to BUP (3.11 ng/mL; 95% CI: -2.56 to 8.79 ng/mL) (P = 0.002). At 4 and 24 h, LID + MEL had lower PGEM concentrations from baseline (-32.42% and -47.84%; 95% CI: -78.45% to -1.80%) compared with CON (27.86% and 47.63%; 95% CI: 7.49% to 82.98%) (P < 0.02). The administration of bupivacaine liposome suspension as a local anesthetic block at the time of castration was as effective at controlling pain as a multimodal approach of lidocaine and meloxicam.

Castration is a routine procedure performed on beef and dairy operations in the United States. All methods of castration cause pain. The American Veterinary Medical Association and the American Association of Bovine Practitioners recommend that anesthesia and analgesia be administered during castration. The objective of this study was to evaluate the effectiveness of bupivacaine liposome suspension, a novel, long-acting, local anesthetic formulation administered as a nerve block at castration, as an alternative to current industry standards using lidocaine nerve blocks alone or in combination with meloxicam. Evidence provided in the current study demonstrates that pain from surgical castration can last up to 120 h post-castration, indicated by changes in ocular temperature, gait analysis, and prostaglandin metabolite concentrations. These data show that the administration of bupivacaine liposome suspension as a local anesthetic block at the time of castration was as effective at controlling pain as a multimodal approach of lidocaine and meloxicam. A single injection that alleviates both perioperative and postoperative pain would be an attractive option for livestock producers to alleviate pain at the time of castration. Further research is needed to discover effective ways of managing pain for extended durations following painful husbandry procedures.

Effect of bupivacaine liposome suspension administered as a cornual nerve block on indicators of pain and distress during and after cautery dehorning in dairy calves.

Dehorning is performed on a high percentage of dairies worldwide. Concern about the negative effect of dehorning on animal welfare has contributed to the development of new guidelines that require the use of pain management at the time of disbudding in the United States. However, livestock producers are limited in how to address this requirement due to a lack of (1) approved analgesic drugs, (2) analgesic options that control pain for an extended duration, and (3) analgesic formulations that are practical for producers to administer. The objective of this study was to evaluate the effectiveness of bupivacaine liposome suspension, a novel, long-acting, local anesthetic formulation administered as a nerve block at dehorning, compared with current industry standard analgesic approaches using lidocaine nerve blocks alone or in combination with the nonsteroidal anti-inflammatory drug meloxicam. Fifty male Holstein calves, 10 to 14 wk of age, were enrolled and randomly assigned to 1 of 5 treatment groups before cautery dehorning as follows: (1) bupivacaine liposome suspension block, oral placebo (BUP); (2) lidocaine block, oral placebo (LID); (3) lidocaine block, oral meloxicam (1 mg/kg of body weight; LID + MEL); (4) saline block, oral placebo (CON); and (5) saline block, oral placebo, sham dehorn (SHAM). Biomarkers were collected from 0 to 120 h postdehorning and included infrared thermography, mechanical nociceptive threshold (MNT), pressure mat gait analysis, chute defense and behavior scoring, and blood sampling for serum cortisol and prostaglandin E2 metabolites. Responses were analyzed using repeated measures with calf nested in treatment designated as a random effect, and treatment, time, and their interaction designated as fixed effects. At 2 h postdehorning, the BUP group had a higher MNT compared with the CON group. Furthermore, at 24 h postdehorning, the BUP group had a higher MNT compared with the LID group. Gait distance differed significantly between treatment groups; the CON, LID, and LID + MEL groups had an increased gait distance relative to the SHAM group. The CON group exhibited a higher chute defense behavior score during the dehorning procedure compared with all other treatments. Furthermore, the CON group exhibited more ear flicks than the BUP and LID + MEL groups postdehorning. At 4 h and 24 h after dehorning, the LID + MEL group had a lower average prostaglandin E2 metabolites concentration compared with all other treatment groups. These data showed that administration of bupivacaine liposome suspension as a cornual nerve block at the time of dehorning was as effective at controlling pain as a multimodal approach of lidocaine and meloxicam.