Comparison of firocoxib and meloxicam for pain mitigation in goats undergoing surgical castration.

OBJECTIVE: This study sought to determine whether firocoxib (FIRO) or meloxicam (MEL) was effective at providing analgesia after surgical castration in goats. ANIMALS: 18 intact male crossbred goats (6 to 8 months old) were enrolled with a mean weight of 32.6 (± 2.9) kg. METHODS: Surgical castration was done under injectable anesthesia by a licensed veterinarian. Twelve bucks were surgically castrated and given either FIRO (n = 6) or MEL (n = 6). Six bucks served as controls (CNTLs) and were not castrated. Outcome measurements included visual analogue scale, infrared thermography, plasma cortisol, plasma substance P, and kinetic gait analysis. All outcome measurements were obtained at -24, 4, 8, 24, 48, and 72 hours. RESULTS: All 3 treatments were significantly different from each other at the 24- and 48-hour time points, with MEL animals having lower visual analogue scale scores when compared to FIRO animals; CNTL animals exhibited the lowest plasma cortisol levels (3.19 ng/mL; 95% CI, -1.21 to 7.59 ng/mL) followed by FIRO (7.45 ng/mL; 95% CI, 3.10 to 11.80 ng/mL) and MEL (10.24 ng/mL; 95% CI, 5.87 to 14.60 ng/mL). FIRO had an average mean decrease in gait velocity change (-54.17 cm/s; 95% CI, -92.99 to -15.35 cm/s), while MEL had an increase in gait velocity when compared to baseline values (14.54 cm/s; 95% CI, -24.27 to 53.36 cm/s). Control animals had an average mean of -3.06 cm/s (95% CI, -41.88 to 35.75 cm/s). CLINICAL RELEVANCE: Results from this study showed that there were some analgesic effects from administering MEL when compared to bucks that received a placebo treatment (CNTL).

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.

Delivering an Immunocastration Vaccine via a Novel Subcutaneous Implant.

Immunocastration relies on the vaccine-mediated stimulation of an immune response to gonadotropin-releasing hormone (GnRH) in order to interrupt spermatogenesis. This approach offers a less painful alternative to traditional castration approaches but the current, commercially available options require multiple doses of vaccine to maintain sterility. Thus, a series of pilot studies were conducted to determine the feasibility of a single-dose immunocastration vaccine implant. These five studies utilized a total of 44 Holstein bulls to determine the optimal vaccine composition and validate the ability of a stainless-steel subcutaneous implant to deliver a vaccine. Outcome measures included the duration of implant retention, scrotal dimensions and temperature, implant site temperature, anti-GnRH antibodies, and serum testosterone concentration. Over the course of several studies, anti-GnRH antibodies were successfully stimulated by vaccine implants. No significant treatment effects on scrotal dimensions or testosterone were detected over time, but changes in spermatogenesis were detected across treatment groups. Results indicate that a single-dose implantable immunocastration vaccine elicits a humoral immune response and could impact spermatogenesis in bulls. These findings provide opportunities for the refinement of this technology to improve implant retention over longer periods of time. Taken together, this approach will offer producers and veterinarians an alternative to physical castration methods, to improve animal welfare during routine livestock management procedures.

Targeted mutagenesis in Anaplasma marginale to define virulence and vaccine development against bovine anaplasmosis.

Tick-borne Anaplasma species are obligate, intracellular, bacterial pathogens that cause important diseases globally in people, agricultural animals, and dogs. Targeted mutagenesis methods are yet to be developed to define genes essential for these pathogens. In addition, vaccines conferring protection against diseases caused by Anaplasma species are not available. Here, we describe a targeted mutagenesis method for deletion of the phage head-to-tail connector protein (phtcp) gene in Anaplasma marginale. The mutant did not cause disease and exhibited attenuated growth in its natural host (cattle). We then assessed its ability to confer protection against wild-type A. marginale infection challenge. Additionally, we compared vaccine protection with the mutant to that of whole cell A. marginale inactivated antigens as a vaccine (WCAV) candidate. Upon infection challenge, non-vaccinated control cattle developed severe disease, with an average 57% drop in packed cell volume (PCV) between days 26-31 post infection, an 11% peak in erythrocytic infection, and apparent anisocytosis. Conversely, following challenge, all animals receiving the live mutant did not develop clinical signs or anemia, or erythrocyte infection. In contrast, the WCAV vaccinees developed similar disease as the non-vaccinees following A. marginale infection, though the peak erythrocyte infection reduced to 6% and the PCV dropped 43%. This is the first study describing targeted mutagenesis and its application in determining in vivo virulence and vaccine development for an Anaplasma species pathogen. This study will pave the way for similar research in related Anaplasma pathogens impacting multiple hosts.

The effect of breed, sex, and oral meloxicam administration on pain biomarkers following hot-iron branding in Hereford and Angus calves.

Hot-iron branding uses thermal injury to permanently identify cattle causing painful tissue damage. The primary objective was to examine the physiological and behavioral effects of oral meloxicam (MEL), compared to a control, administered at the time of hot-iron branding in Angus and Hereford steers and heifers. The secondary objectives were to investigate breed and sex effects on pain biomarkers. A total of 70 yearlings, consisting of 35 heifers and 35 steers (Angus, Hereford, or Angus × Hereford), were enrolled in the study. Animals were blocked by sex, randomized across weight, and assigned to receive MEL (1 mg/kg) or a placebo (CON). Biomarkers were assessed for 48 h after branding and included infrared thermography (IRT), mechanical nociceptive threshold (MNT), accelerometry and a visual analog scale (VAS), and serum cortisol and prostaglandin E2 metabolites (PGEM). Wound healing was assessed for 12 wk. Hair samples to quantify cortisol levels were taken prior to and 30 d post-branding. Responses were analyzed using repeated measures with calf nested in treatment as a random effect, and treatment, time, treatment by time interaction, breed, and sex as fixed effects. There was a treatment by time interaction for PGEM (P < 0.01) with MEL having lower values than CON at 6, 24, and 48 h (MEL: 18.34 ± 3.52, 19.61 ± 3.48, and 22.24 ± 3.48 pg/mL, respectively; CON: 32.57 ± 3.58, 37.00 ± 3.52, and 33.07 ± 3.48 pg/mL; P < 0.01). MEL showed less of a difference in maximum IRT values between the branded (2.27 ± 0.29 °C) and control site (3.15 ± 0.29 °C; P < 0.01). MEL took fewer lying bouts at 0-12 h (4.91 bouts ± 0.56) compared with CON (6.87 bouts ± 0.55; P < 0.01). Compared with Hereford calves, Angus calves exhibited greater serum but lower hair cortisol, greater PGEM, more lying bouts, and less healed wound scores at 3, 4, and 5 wk. Compared with heifers, steers exhibited lower PGEM, lower branding site and ocular IRT, higher MNT, and lower plasma meloxicam levels. Steers spent more time lying, took more lying bouts and had greater VAS pain, and more healed wound scores at 5 wk than heifers. Meloxicam administration at branding reduced branding and control site temperature differences and reduced lying bouts for the first 12 h. Breed and sex effects were observed across many biomarkers. Changes from baseline values for IRT, MNT, lying time, step count, VAS pain, and wound scoring all support that branding cattle is painful.

Hot-iron branding uses thermal injury to permanently identify cattle causing painful tissue damage. The primary objective was to examine the effects of oral meloxicam (MEL), compared with a control, administered at the time of hot-iron branding in Angus and Hereford steers and heifers. The secondary objectives were to investigate breed and sex effects on pain biomarkers. A total of 70 yearlings, consisting of 35 heifers and 35 steers (Angus, Hereford, or Angus × Hereford), were enrolled. Animals were assigned to receive MEL or a placebo. Changes from baseline values for infrared thermography (IRT), mechanical nociceptive threshold, lying time, step count, visual analog scale score, and wound scoring all support that hot-iron branding cattle is painful and investigation into analgesic strategies is needed. MEL administration reduced IRT differences from the branding and control site and reduced lying bouts. Breed and sex effects were observed across a wide range of biomarkers and should be considered in future pain studies. The practicality of administering a nonsteroidal anti-inflammatory drug once at the time of branding is attractive. However, a multimodal approach using a combination of analgesics or longer acting analgesic option warrants further investigation to alleviate pain and discomfort caused by hot-iron branding.

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.

Assessment of pain associated with bovine respiratory disease and its mitigation with flunixin meglumine in cattle with induced bacterial pneumonia.

Pleuritic chest pain from bacterial pneumonia is often reported in human medicine. However, studies investigating pain associated with bovine respiratory disease (BRD) are lacking. The objectives of this study were to assess if bacterial pneumonia elicits a pain response in calves with experimentally induced BRD and to determine the analgesic effects of transdermally administered flunixin. A total of 26 calves, 6-7 mo of age, with no history of BRD were enrolled into one of three treatment groups: 1) experimentally induced BRD + transdermal flunixin at 3.3 mg/kg twice, 24 h apart (BRD + FTD); 2) experimentally induced BRD + placebo (BRD + PLBO); and 3) sham induction + placebo (CNTL + PLBO). Calves induced with BRD were inoculated with Mannheimia haemolytica via bronchoalveolar lavage. Outcomes were collected from -48 to 192 h post-treatment and included serum cortisol, infrared thermography, mechanical nociceptive threshold, substance P, kinematic gait analysis, visual analog scale (VAS), clinical illness score, computerized lung score, average activity and rumination level, prostaglandin E2 metabolite, plasma serum amyloid A, and rectal temperature. Outcomes were evaluated using either a generalized logistic mixed model for categorical variables or a generalized linear mixed model for continuous variables. Right front force differed by treatment (P = 0.01). The BRD + PLBO had lower mean force applied to the right front limb (85.5 kg) compared with BRD + FTD (96.5 kg; P < 0.01). Average VAS differed by a treatment by time interaction (P = 0.01). The VAS scores differed for BRD + PLBO at -48 (3.49 mm) compared with 168 and 192 h (13.49 and 13.64 mm, respectively) (P < 0.01). Activity for BRD + PLBO was higher at -48 h (27 min/h) compared with 48, 72, 120, and 168 h (≤ 22.24 min/h; P < 0.01). Activity differed by a treatment by time interaction (P = 0.01). Activity for BRD + FTD was higher at -48 and 0 h (28.2 and 28.2 min/h, respectively) compared to 48, 72, 96, and 168 h (≤23.7 min/h; P < 0.01). Results show a combination of reduced activity levels, decreased force on the right front limb, and increased VAS pain scores all support that bacterial pneumonia in cattle is painful. Differences in right front force indicate that flunixin transdermal may attenuate certain pain biomarkers in cattle with BRD. These findings suggest that BRD is painful and analgesic drugs may improve the humane aspects of care for cattle with BRD.

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.

Failure to Eliminate Persistent Anaplasma marginale Infection from Cattle Using Labeled Doses of Chlortetracycline and Oxytetracycline Antimicrobials.

Bovine anaplasmosis, caused by the intracellular rickettsial pathogen Anaplasma marginale, is the most prevalent tick-transmitted disease of cattle worldwide. In the U.S., tetracycline antimicrobials are commonly used to treat and control anaplasmosis. Oxytetracycline, administered by injection, is indicated for treatment of clinical anaplasmosis in beef and dairy cattle and calves. Chlortetracycline, administered orally, is indicated for control of active anaplasmosis infection in beef and nonlactating dairy cattle. Tetracyclines have been demonstrated to be effective for treating active anaplasmosis, but their ability to eliminate A. marginale at currently approved therapeutic doses or dosing regimens remains unclear. In the absence of approved dosing regimens for A. marginale clearance, a study was conducted to determine the effect of approved oxytetracycline and chlortetracycline indications on A. marginale bacteremia. Fifteen animals with persistent anaplasmosis were enrolled and divided into three treatment groups. Group 1 (n = 6) received oral chlortetracycline (1.1 mg/kg bodyweight) administered via hand-fed medicated feed for 60 consecutive days. Group 2 (n = 6) received injectable oxytetracycline administered subcutaneously at 19.8 mg/kg bodyweight three times in 3-week intervals. Group 3 (n = 3) served as an untreated control. After 60 days, bacteremia failed to permanently decrease in response to treatment. This result indicates that clearance of A. marginale is unlikely to be reliably achieved using currently approved tetracycline-based regimens to manage anaplasmosis.

Development of a subcutaneous ear implant to deliver an anaplasmosis vaccine to dairy steers.

Bovine anaplasmosis is the most prevalent tick-transmitted disease of cattle worldwide and a major obstacle to profitable beef production. Use of chlortetracycline-medicated feed to control active anaplasmosis infections during the vector season has raised concerns about the potential emergence of antimicrobial resistance in bacteria that may pose a risk to human health. Furthermore, the absence of effectiveness data for a commercially available, conditionally licensed anaplasmosis vaccine is a major impediment to implementing anaplasmosis control programs. The primary objective of this study was to develop a single-dose vaccine delivery platform to produce long-lasting protective immunity against anaplasmosis infections. Twelve Holstein steers, aged 11 to 12 wk, were administered a novel 3-stage, single-dose vaccine against Anaplasma marginale, a major surface protein 1a. The vaccine consisted of a soluble vaccine administered subcutaneously (s.c.) for immune priming, a vaccine depot of a biodegradable polyanhydride rod with intermediate slow release of the vaccine for boosting immune response, and an immune-isolated vaccine platform for extended antigen release (VPEAR implant) deposited s.c. in the ear. Six calves were randomly assigned to 2 vaccine constructs (n = 3) that featured rods and implants containing a combination of 2 different adjuvants, diethylaminoethyl (DEAE)-Dextran and Quil-A (Group A). The remaining 6 calves were randomly assigned to 2 vaccine constructs (n = 3) that featured rods and implants containing the same adjuvant (either DEAE-Dextran or Quil A) (Group B). Twenty-one months post-implantation, calves were challenged intravenously with A. marginale stabilate and were monitored weekly for signs of fever, decreased packed cell volume (PCV) and bacteremia. Data were analyzed using a mixed-effects model and chi-squared tests (SAS v9.04.01, SAS Institute, Cary, NC). Calves in Group A had higher PCV than calves in Group B (P = 0.006) at day 35 post-infection. Calves in Group A were less likely to require antibiotic intervention compared with calves in Group B (P = 0.014). Results indicate that calves exhibited diminished clinical signs of anaplasmosis when antigen was delivered with a combination of adjuvants as opposed to a single adjuvant. This demonstrates the feasibility of providing long-lasting protection against clinical bovine anaplasmosis infections using a subcutaneous ear implant vaccine construct.