Pre‐emptive meloxicam for postoperative analgesia in piglets undergoing surgical castration

ObjectiveTo investigate the effect of preoperative meloxicam administration on postoperative stress and pain induced by surgical castration in piglets.Study designProspective, blinded, randomized clinical trial.AnimalsOne hundred and eighty male piglets of <1 week of age.MethodsCastration was performed on 150 piglets which had received either an intramuscular injection of 0.4 mg kg^?1 meloxicam or a placebo 10–30 minutes before the procedure. Blood cortisol and ACTH concentrations were determined at 30 minutes post–castration and haptoglobin was measured at 24 hours post–castration. Presence or absence of foreleg movements, hind leg movements, urine or faeces emission, tremors or other body movements were recorded during the castration procedure. Scores for presence or absence of prostration, tremors, tail movements and isolation were recorded at 30 minutes, and at 1, 2, 4 and 24 hours post–castration and combined in a global behaviour score (GBS). Blood samples were taken from a further 30 piglets which did not undergo castration.ResultsMean blood cortisol and ACTH concentrations at 30 minutes post–castration were both significantly lower in the meloxicam group than in the placebo group (p ≤ 0.01). The mean haptoglobin concentration at 24 hours was not significantly reduced (p = 0.178). The distribution of the GBS during castration was similar in both groups. There were significant differences in the GBS after castration at both 2 and 4 hours post–castration with a greater proportion of piglets in the meloxicam group showing no behavioural alterations (82.7%versus 68.0% at both time points). The score distribution was similar in both groups at 30 minutes, 1 and 24 hours after castration.Conclusion and clinical relevanceThis study suggests that pre–emptive administration of meloxicam is able to produce some postoperative analgesia after surgical castration of young piglets.     

Behavioural and cortisol responses of lambs to castration and tailing using different methods

Lambs at 4-5 weeks of age were studied during the first 4 hours after castration and/or tailing using three methods in various commonly used combinations. The methods were: cutting with a knife, application of constricting rubber rings and using a heated docking iron (tailing only). Behaviour was monitored by quantifying the incidences of restlessness (during the first hour only), normal and abnormal standing/walking, and normal and abnormal lying. Plasma cortisol concentrations were also measured in samples taken at intervals during the 4 hours after treatment. With the knife, abnormal standing/walking predominated throughout the fist 4 hours and beyond, and restlessness was virtually absent. Plasma cortisol concentrations in knife-treated lambs remained above pretreatment values for at least 4 hours. With rings, high restlessness was invariably present during the first 30-45 minutes, and much of the associated standing/walking and lying was abnormal, but all behaviours had returned to control values within 4 hours of treatment, as had the plasma cortisol concentrations. There were no correlations between the incidences of abnormal behaviours and the plasma cortisol concentrations during the first 4 hour after any treatment, except that when abnormal behaviour was present the cortisol concentrations were greater than pretreatment values, and vice versa. Thus, the presence/absence of the abnormal behaviours reported here allowed an assessment of the duration of distress after castration and/or tailing. However, as the behavioural responses to castration and/or tailing were broadly procedure-specific, so that the responses to the knife and rings were not apparently part of the one behavioural continuum, it is argued that the relative intensities of distress caused by the two procedures cannot be assessed from behaviour alone. Rather, reference must also be made to established physiological indices of distress such as plasma cortisol concentration. On that basis, the knife treatments apparently caused greater and more protracted distress responses than did the ring or docking iron treatments, and should therefore be avoided. However, ring-treated lambs, especially those castrated or castrated and tailed apparently experienced distress, so that more benign alternatives to the use of rings should also be sought.     

Effect of repeated ketoprofen administration during surgical castration of bulls on cortisol,immunological function,feed intake,growth, and behavior

To determine the effect of repeated ketoprofen (K) administration to surgically castrated bulls on cortisol, acute-phase proteins, immune function, feed intake, growth and behavior, 50 Holstein x Friesian bulls (11 mo old; 300 +/- 3.3 kg) were assigned to one of five treatments: 1) untreated control (C); 2) surgical castration at 0 min (S); 3) S following an i.v. injection of 3 mg/kg of BW of K at -20 min (SK1); 4) S following 1.5 mg/kg of BW of K at -20 and 0 min (SK2); or 5) S following 1.5 mg/kg of BW of K at -20 and 0 min and 3 mg/kg of BW of K at 24 h (SK3). Castration acutely increased plasma cortisol concentrations in S- and K-treated animals compared with C, with no differences in peak and interval to peak cortisol responses among the castration groups. Overall, the integrated cortisol response was greater (P < 0.05) in the castrates than in C, whereas K treatments decreased (P < 0.05) this response compared with S alone, with no differences between K treatments. Plasma haptoglobin and fibrinogen concentrations were increased (P < 0.05) on d 3 in the castration groups compared with C as the result of tissue trauma induced by castration, whereas SK1 and SK2 had lower (P < 0.05) haptoglobin concentrations than S animals. On d 1, concanavalin A-induced interferon-gamma production was suppressed (P < 0.05) in S and SK3 compared with C, SK1, and SK2 animals. Overall from d 1 to 33, DMI were lower (P < 0.05) in S, SK1, and SK3 than in C animals. From d -1 to 35, ADG were lower (P < 0.05) in S, SK2, and SK3 compared with C animals. A higher (P < 0.05) incidence of standing postures and lower incidence of lying postures was observed in S compared with C during the first 6 h after treatment. However, the higher (P = 0.02) incidence of abnormal standing activities observed for S was reversed (P < 0.05) by the K treatments. In conclusion, surgical castration increased plasma cortisol and acute-phase proteins and decreased immune function, feed intake, and growth rate. Ketoprofen effectively reduced the cortisol response to castration, but there was no advantage in treating with two split doses of K (1.5 mg/kg of BW per dose). A repeated K dose 24 h after treatment (3 mg/kg of BW) had no influence on changes in acute-phase proteins and immune response. Systemic analgesia with K is an effective method for alleviating acute inflammatory stress associated with castration.     

The effect of a topical anaesthetic formulation, systemic flunixin and carprofen, singly or in combination, on cortisol and behavioural responses of Merino lambs to mulesing

OBJECTIVE: To determine the pain responses of lambs to mulesing, and the effectiveness of potential analgesic treatments. PROCEDURES: Merino lambs (n=64) were allocated at 5 weeks of age to eight treatment groups: 1) sham mules; 2) conventional mules; 3) topical anaesthetic, incorporating lignocaine, bupivicaine, adrenaline and cetrimide, applied immediately after mulesing; 4) flunixin + topical anaesthetic, with flunixin administered 2.5 mg/kg s.c. 90 min before mulesing; 5) carprofen + topical anaesthetic, with carprofen administered 4 mg/kg s.c. 90 min before mulesing; 6) carprofen, administered as above; 7) flunixin, administered as above; and 8) carprofen + flunixin, administered as above. Plasma cortisol was measured at 0, 0.5, 6, 12 and 24 h relative to mulesing. Animal behaviour, including posture, was recorded for 12 h after mulesing. RESULTS: The conventional mules lambs exhibited large increases in plasma cortisol, reduced lying and increased standing with a hunched back compared with sham mules animals. Topical anaesthetic reduced the cortisol peak to mulesing and hunched standing, and increased lying compared with the conventional mules treatment, but generally did not result in values equivalent to sham mules animals. Carprofen, flunixin, and carprofen + flunixin treatments did not reduce the cortisol response to mulesing but substantially ameliorated some changes in behavioural postures. Flunixin + topical anaesthetic reduced the cortisol peak following mulesing and substantially ameliorated most changes in behavioural postures. Carprofen + topical anaesthetic abolished the cortisol peak following mulesing and substantially ameliorated most changes in behavioural postures. All mulesed animals lost weight in the week after mulesing regardless of analgesic administration, but there were no significant differences in growth rate between any of the eight treatments over the 3 weeks after mulesing. CONCLUSIONS: Analgesics can moderate the pain response of lambs to mulesing. The welfare outcome for lambs of mulesing could be improved by use of a combination of local anaesthetic and long acting non-steroidal anti-inflammatory drug.     

Effects of a topical anaesthetic formulation and systemic carprofen, given singly or in combination, on the cortisol and behavioural responses of Merino lambs to castration

Objective   To determine the effectiveness of a topical anaesthetic formulation (Tri-Solfen) with or without the administration of a non-steroidal anti-inflammatory drug (carprofen) on the pain and distress response associated with ring or surgical castration of ram lambs.
Procedures   Merino ram lambs (n = 78) were allocated to 10 treatment groups: 4 groups of knife-castrated lambs and 4 groups of ring-castrated lambs received carprofen (4 mg/kg SC) and Tri-Solfen; 2 control groups (sham) received carprofen at 0 or 4 mg/kg SC. Measurements included plasma cortisol and haptoglobin concentrations, haematology, and behaviour, including posture.
Results   Knife-castrated lambs had higher peak cortisol and integrated cortisol responses for the first 6 h after treatment and greater concentration s of circulating acute phase proteins than ring-castrated lambs, both of which were significantly different from the sham controls. Tri-Solfen applied to the knife castration wound significantly reduced both the peak plasma cortisol concentration and the integrated cortisol response for the first 6 h and improved lying behaviour in the first 12 h. Carprofen reduced the cortisol response to knife castration at 30 min, but elevated the cortisol responses at 24 and 48 h. Carprofen nearly halved the number of acute pain behaviours associated with ring castration. There were no significant additive or synergistic effects from combining the analgesic treatments. Tri-Solfen applied to the tail wound provided no detectible benefits during ring castration + tail docking.
Conclusions   The physiological and behavioural responses suggest that ring castration has less impact on the lamb than knife castration. The specific analgesic treatments can provide modest amelioration of the pain and discomfort associated with castration. Alternative doses or application methods may enhance their efficacy.     

Physiological and behavioural effects of intradermal injection of sodium lauryl sulfate as an alternative to mulesing in lambs

Objective To assess the effects on physiology and behaviour of intradermal injection of sodium lauryl sulfate (SLS) as an alternative to mulesing. Procedures Three groups of Merino lambs were studied: Control (n = 10), SLS (n = 11) and Mulesed (n = 11). The SLS group received SLS (7% w/v) and benzyl alcohol (20 mg/mL) in phosphate buffer, and the Mulesed group received 6 mL topical local anaesthetic as a wound dressing. Haematology, cortisol, beta-endorphin and haptoglobin concentrations, rectal temperatures, body weight and behaviours were monitored for up to 42 days post treatments. Results SLS treatment induced mild swelling followed by thin scab formation. Fever (>40°C) was observed at 12 and 24 h, cortisol concentration was elevated on days 1 and 2, haptoglobin concentration was highly elevated on days 2–7, white blood cell count was elevated on days 2 and 4 post treatment, but average daily gain was not affected. Fever at 12 h was significantly higher in the SLS than in the Mulesed group, whereas maximum temperature, temperature area under the curve (AUC), occurrence of fever, cortisol profile, cortisol AUC, white blood cell counts and haptoglobin concentrations until day 7 were comparable. The behaviours of normal standing, total standing and total lying were modified for 2 days by SLS treatment, but changes were less marked and of shorter duration than in the Mulesed group. On day 1, the SLS group spent <5% of time in total abnormal behaviours compared with 18% in the Mulesed group. The SLS group tended to spend more time in abnormal behaviours on day 1 than the Controls. Conclusions The behaviour of the SLS group was similar to that of the unmulesed Controls and their physiological responses were intermediate between the Mulesed lambs receiving post-surgical analgesia and the Controls.     

The pharmacokinetics and effects of meloxicam,gabapentin, and flunixin in postweaning dairy calves following dehorning with local anesthesia

Approved analgesic compounds in cattle are not currently available in the United States due to the lack of validated pain assessment methods and marker residue depletion studies. In this study, we compared the pharmacokinetic parameters and effect of preemptive analgesics administered to calves subjected to dehorning with local anesthesia. Holstein steers were randomly assigned to receive one of the following treatments per os (PO) or intravenously (IV) (n = 8/group): meloxicam (1 mg/kg PO), gabapentin (15 mg/kg PO), meloxicam (1 mg/kg), and gabapentin (15 mg/kg) PO, flunixin (2.2 mg/kg IV), or a placebo. Plasma drug, haptoglobin, substance P (SP) concentrations, serum cortisol concentrations, ocular thermography, mechanical nociceptive threshold (MNT), and average daily gain (ADG) were evaluated. Data were analyzed using mixed‐effects models and noncompartmental pharmacokinetic analysis. Meloxicam, gabapentin, and meloxicam with gabapentin at the present doses did not reduce cortisol concentrations. Analgesic‐treated calves had significantly lower plasma SP concentrations and improved ADG compared with controls. Flunixin calves had reduced circulating cortisol compared with controls. Meloxicam‐treated calves showed an increase in MNT at two horn bud sites compared with the other treatments. Analgesics improved ADG and reduced biomarkers of pain, but effects differed by compound and route of administration.     

Effects of the cyclooxygenase inhibitor meloxicam on recovery of ischemia-injured equine jejunum

OBJECTIVE: To determine the effect of meloxicam and flunixin meglumine on recovery of ischemia-injured equine jejunum. ANIMALS: 18 horses. PROCEDURES: Horses received butorphanol tartrate; were treated IV with saline (0.9% NaCl) solution (SS; 12 mL; n = 6), flunixin meglumine (1.1 mg/kg; 6), or meloxicam (0.6 mg/kg; 6) 1 hour before ischemia was induced for 2 hours in a portion of jejunum; and were allowed to recover for 18 hours. Flunixin and SS treatments were repeated after 12 hours; all 3 treatments were administered immediately prior to euthanasia. Selected clinical variables, postoperative pain scores, and meloxicam pharmacokinetic data were evaluated. After euthanasia, assessment of epithelial barrier function, histologic evaluation, and western blot analysis of ischemia-injured and control jejunal mucosa samples from the 3 groups were performed. RESULTS: Meloxicam- or flunixin-treated horses had improved postoperative pain scores and clinical variables, compared with SS-treated horses. Recovery of transepithelial barrier function in ischemia-injured jejunum was inhibited by flunixin but permitted similarly by meloxicam and SS treatments. Eighteen hours after cessation of ischemia, numbers of neutrophils in ischemia-injured tissue were higher in horses treated with meloxicam or flunixin than SS. Plasma meloxicam concentrations were similar to those reported previously, but clearance was slower. Changes in expression of proteins associated with inflammatory responses to ischemic injury and with different drug treatments occurred, suggesting cyclooxygenase-independent effects. CONCLUSIONS AND CLINICAL RELEVANCE: Although further assessment is needed, these data have suggested that IV administration of meloxicam may be a useful alternative to flunixin meglumine for postoperative treatment of horses with colic.     

Influences of carprofen and the experience of the surgeon on post-castration pain in lambs and young sheep

This study evaluated the influences of carprofen and the experience of the surgeon on post‐castration pain in lambs and young sheep castrated in the field. A total of 201, 1–6‐week‐old lambs with a mean body mass of 11.0 ± 2.4 kg (mean ± SD) were castrated after local application of 4 mL lidocaine (2%). Preoperatively lambs were given either 20 mg carprofen SC or an equal volume of saline in a randomized order. A further 34 sheep, aged 6 months, with a mean body mass of 36.0 ± 4.5 kg were castrated after local application of 7 mL lidocaine (2%). Preoperatively sheep received 2 mg kg^?1 carprofen SC or an equal volume of saline in a randomized order. Lidocaine was injected SC in front of, behind and into each spermatic cord. All surgery was performed using the same Burdizzo clamp (jaw 45 mm wide, handles 225 mm) either by students or experienced veterinary surgeons. Pain was assessed preoperatively and at 24, 48 and 72 hours after castration by two independent observers unaware of the treatment group. Observers scored pain using a visual analog scale (100 mm) after applying gentle pressure onto the scrotal region ( Thornton & Waterman‐Pearson 1999 ). Swelling of the scrotal region was scored as ‘severe’, ‘present but not severe’ and ‘not present’. The VAS scores were compared using a Mann–Whitney test, p < 0.05 was considered significant. Swelling was compared using Fisher's exact test. In lambs, no significant differences in pain scores between those treated with carprofen or saline were noted by either observer (p > 0.48) at any of the three assessment times. However, the number of lambs with severe or present swelling of the scrotal region was significantly lower in those receiving carprofen (8% versus 18%, p = 0.028). Lambs castrated by students showed significantly higher pain scores (23% versus 13%, p < 0.001 at 24 hours; 20% versus 13%, p = 0.0062 at 48 hours; 16% versus 10%, p = 0.0088 at 72 hours) and significantly more swelling (18% versus 8%, p = 0.0189) of the scrotal region than those castrated by veterinary surgeons. Young sheep receiving carprofen preoperatively had significantly lower pain scores (12 mm versus 25 mm, p = 0.037) 24 hours after surgery compared to sheep receiving saline. No scrotal swelling was obvious in sheep. Juvenile sheep but not lambs, receiving carprofen preoperatively showed reduced pain scores up to 24 hours after surgery. Carprofen reduced swelling of the scrotum in lambs. Lambs castrated by experienced surgeons scored lower VAS scores at all times and showed less swelling of the scrotal region.     

Effect of ketoprofen,lidocaine local anesthesia,and combined xylazine and lidocaine caudal epidural anesthesia during castration of beef cattle on stress responses,immunity, growth,and behavior

To determine the effects of burdizzo castration alone or in combination with ketoprofen (K), local anesthesia (LA), or caudal epidural anesthesia (EPI) on plasma cortisol, acute-phase proteins, interferon-gamma production, growth, and behavior of beef cattle, 50 Holstein x Friesian bulls (13 mo old, 307 +/- 5.3 kg) were assigned to (n = 10/treatment): 1) control (handled; C); 2) burdizzo castration (B); 3) B following K (3 mg/ kg of BW i.v.; BK); 4) B following LA (8 mL into each testis and 3 mL s.c. along the line where the jaws of the burdizzo were applied with 2% lidocaine HCl; BLA); and 5) B following EPI (0.05 mg/kg of BW of xylazine HCl and 0.4 mg/kg of BW of lidocaine HCl as caudal epidural; BEPI). The area under the cortisol curve against time was lower (P < 0.05) in BK than in B, BLA, or BEPI animals. On d 1 after treatment, plasma haptoglobin concentrations were higher (P < 0.05) in B, BLA, and BEPI than in BK animals. On d 3, haptoglobin and plasma fibrinogen concentrations were higher (P < 0.05) in all castration groups than in C. On d 7, haptoglobin and fibrinogen concentrations remained higher (P < 0.05) in BLA than in B and C animals. On d 1, concanavalin A-induced interferon-gamma production was lower (P < 0.05) in B, BLA, and BEPI than in C, but there was no difference between BK and C animals. From d -1 to 35, ADG was lower (P < 0.05) in B, BLA, and BEPI animals, but not in BK compared with C animals. Overall, there was a higher (P < 0.05) incidence of combined abnormal postures in B than in C, BK and BEPI animals. Although the use of K and EPI decreased (P < 0.05) these postures compared with B alone or B with LA, there was no difference between the K and EPI treatment. In conclusion, burdizzo castration increased plasma cortisol and acute-phase proteins, and suppressed immune function and growth rates. Local anesthesia prolonged the increase in acute-phase proteins. Ketoprofen was more effective than LA or EPI in decreasing cortisol and partially reversed the reduction in ADG following castration. The use of K or EPI was more effective than LA in decreasing pain-associated behavioral responses observed during the first 6 h after treatment. Systemic analgesia with ketoprofen, a non-steroidal antiinflammatory drug, was more effective in reducing inflammatory responses associated with castration than LA or EPI.     

Acute cortisol responses of lambs to castration using a rubber ring and/or a castration clamp with or without local anaesthetic

Changes in plasma cortisol concentrations during the first 4 hours after castration of 6-week-old lambs by one of four methods were measured. The methods were application of a rubber ring above the testes, application of a ring to shorten the scrotum below the testes, use of a castration clamp plus a ring, and use of a castration clamp alone. The efficacy of local anaesthetic in reducing or abolishing the cortisol responses to castration by all these methods except short scrotum was assessed. Local anaesthetic was injected into the neck of the scrotum, both spermatic cords, the scrotal neck plus spermatic cords, or into both testes. The combined clamp plus ring method was used to test whether or not clamp damage to afferent nerves from the testes would reduce the cortisol response to ring castration. The short scrotum method elicited a significantly lower cortisol response than that caused by ring castration. Injection of local anaesthetic into both spermatic cords marginally reduced the cortisol response to ring castration, but the response was virtually abolished by prior scrotal neck, or scrotal neck plus spermatic cords, or intra-testicular local anaesthetic injections. The clamp plus ring method, where each spermatic cord and the associated scrotal tissue were crushed separately for 1, 5 or 10 seconds with no overlap between the two crush lines, did not elicit lower cortisol responses than the ring-only method. Local anaesthetic injected into the scrotal neck virtually abolished, and spermatic cord injections markedly reduced, the cortisol responses to combined clamp plus ring castration. The IO-second clamp application caused a more protracted cortisol response than did ring-only castration, whereas the cortisol responses to 1-second clamp application and to ring-only castration were similar. Local anaesthetic injected into the scrotal neck or spermatic cords did not affect significantly the cortisol response to the IO-second clamp application. The following conclusions were drawn from this work: the testes as well as the scrotum were sources of noxious sensory input after ring application; the clamp plus ring method used here was ineffective in reducing the pain-induced distress (as indicated by cortisol concentrations) caused by ring-only castration; injection of local anaesthetic into the scrotal neck or into the testes prior to ring application blocked most noxious sensory input from both the scrotum and the testes; and on the basis of the present cortisol responses the 10-second clamp applications method could not be recommended in reference to the ring-only method, but the l-second clamp application method might be equally acceptable for castrating 6-week-old-lambs. Of the methods examined, injections of local anaesthetic into the scrotal neck or both testes were the most effective in reducing the pain-induced distress caused by ring-only castration.     

Reduction in pain suffered by lambs at castration

The acute pain produced by bloodless castrators was studied by comparing the behavioural and plasma cortisol changes in groups (n=8) of 3-week-old Dorset cross lambs after castration with a 22 cm (9") Burdizzo, a new power assisted castrator and by a combined method using a Burdizzo and elastrator ring. The time spent in abnormal postures (52-58 min) and the peak cortisol response (110-120 mmol l(-1)) were similar for the three methods, although the powered castrator produced a more sustained response. The Burdizzo method halved the incidence of active behaviours compared with the powered castrator and combined methods (16 versus 30, 32 counts). Intratesticular local anaesthetic administered 2 min before the Burdizzo castrator and combined method, or intramuscular injection of the non-steroidal anti-inflammatory drug diclofenac, 20 min before the application of a Burdizzo, significantly reduced the peak plasma cortisol response to 80 nmol l(-1). Diclofenac also significantly reduced the time spent trembling or in abnormal postures.     

Effects of nonsteroidal anti-inflammatory drugs on long-term pain in calves castrated by use of an external clamping technique following epidural anesthesia

OBJECTIVE: To compare efficacy of flunixin meglumine versus carprofen in controlling pain under field conditions following castration by use of an external clamping technique in calves that received epidural anesthesia. ANIMALS: 40 male 5- to 6-month-old calves. PROCEDURES: Calves were allocated to 4 groups: castrated only (control calves; n=8); castrated 5 minutes after epidural injection of 2% lidocaine (epidural-alone treated calves; 8), castrated after epidural anesthesia and s.c. administration of flunixin meglumine (epidural-flunixin treated calves; 12), and castrated after epidural anesthesia and s.c. administration of carprofen (epidural-carprofen-treated calves; 11 [1 calf not included]). Plasma cortisol concentration was measured before and 6, 24, and 48 hours after castration. Time of arrival at the feed trough at 24 and 48 hours was observed. Calves were observed at 24 and 48 hours for 4 pain-related behaviors. RESULTS: At 6 hours, control calves had significantly higher plasma cortisol concentrations, compared with baseline values and those of epidural-flunixin- and epidural-carprofen-treated calves. At 24 hours, epidural-carprofen-treated calves had significantly lower plasma cortisol concentrations, compared with control calves. At 48 hours, epidural-carprofen-treated calves had plasma cortisol concentrations that were similar to baseline values and significantly lower than epidural-flunixin- and epidural-alone-treated calves. At 24 and 48 hours, epidural-carprofen-treated calves were first to arrive at the feed trough and had fewer pain-related behaviors. CONCLUSIONS AND CLINICAL RELEVANCE: s.c. administration of carprofen in combination with epidural injection of lidocaine may improve the welfare of calves castrated by use of an external clamping technique for up to 48 hours.     

Effect of age at castration on behavioural response to subsequent tail docking in lambs

Objective To investigate the effects of age at castration on the subsequent behavioural response to tail docking. Study design Randomised prospective blinded experimental study. Animals Forty‐five male lambs were admitted to the study at birth. Methods The lambs were allocated into two groups for castration by rubber ring at 1 (1D, n = 20) or 10 (10D, n = 25) days of age. Following castration both groups of lambs were tail‐docked by rubber ring at between 26 and 34 days of age. Their behavioural responses to tail docking were recorded by video for 30 minutes before (n = 11) and 30 minutes after (n = 45) tail docking. Statistical differences were tested using anova with Mann‐Whitney post‐hoc testing. Results Two data sets were removed resulting in n = 19 and = 24 at 1D and 10D, respectively. A significant increase in the incidence of active and abnormal postural behaviour was seen in both groups after tail docking. Three behaviours were significantly different (p < 0.05) between the two groups. These behaviours were rolling, standing unsteadily and the total proportion of time standing with abnormal posture. These behaviours all had greater incidence in the lambs castrated at 1D of age. Conclusions Lambs castrated at 1D appeared to perceive a greater intensity of pain after subsequent tail docking than lambs castrated at 10D. Clinical relevance The timing of a single noxious stimulus in young animals can affect subsequent pain perception.     

Ex vivo COX-1 and COX-2 inhibition in equine blood by phenylbutazone,flunixin meglumine,meloxicam and firocoxib: Informing clinical NSAID selection

Newer cyclo-oxygenase-2 (COX-2) selective nonsteroidal anti-inflammatory drugs (NSAIDs), such as firocoxib, are proposed to reduce inhibition of cyclo-oxygenase-1 (COX-1) and avoid undesirable side effects, while continuing to inhibit inflammation associated with COX-2. However, COX selectivity is typically based on in vitro testing, which may not provide sufficient information critical for treatment selection. This study investigated the pharmacokinetics and ex vivo COX-1 and COX-2 inhibition of phenylbutazone, flunixin meglumine, meloxicam and firocoxib. Horses (n = 3) were administered one of the four drugs, in a randomised cross-over design, with 3-week washout periods. For each drug, three doses were given and sampling performed. Drug plasma concentrations, thromboxane B₂ (TXB₂) and prostaglandin E₂ (PGE₂) were determined. After one dose, TXB₂ and PGE₂ levels were significantly higher in horses administered firocoxib compared to flunixin meglumine. Following the third dose, TXB₂ levels in horses administered firocoxib and meloxicam were significantly higher compared to flunixin meglumine or phenylbutazone; all drugs reduced PGE₂ to a similar degree. The mean plasma half-lives were 5.97 ± 0.47, 4.74 ± 0.14, 8.24 ± 3.74 and 47.42 ± 7.41 h for phenylbutazone, flunixin meglumine, meloxicam and firocoxib, respectively. Firocoxib and meloxicam exhibited significantly less COX-1 inhibition compared to flunixin meglumine and phenylbutazone; all drugs inhibited COX-2. The plasma half-life of firocoxib was longer than the other NSAIDs, including meloxicam. Data from this study have important clinical relevance and should be used to inform practitioners’ drug selection of a COX-1 sparing or traditional NSAID and dose selection and to provide knowledge of the duration for the four NSAIDs studied.     

Post‐anesthetic pulmonary edema in two horses

Case 1 A two‐year old, 462 kg Standard bred horse was anesthetized for arthroscopy and castration. During anesthesia, hyperemia of the mucosal membranes and urticaria were noticed. During 5 hours of anesthesia subcutaneous edema of the eyelids and neck region developed. In the recovery box, the orotracheal (OT) tube was left in situ and secured in place with tape. Following initial attempts to stand, the horse became highly agitated and signs consistent with pulmonary edema developed subsequently. Arterial hypoxemia (PaO₂: 3.7 kPa [28 mmHg]) and hypocapnia (PaCO₂: 3.1 kPa [23 mmHg]) were confirmed. Oxygen and furosemide were administered. The horse was assisted to standing with a sling. Therapy continued with bilateral intra‐nasal oxygen insufflation. Ancillary medical therapy included flunixin meglumine, penicillin, gentamycin and dimethylsulfoxide. Following 7 hours of treatment the arterial oxygen tensions began to increase towards normal values. Case 2 An 11‐year old, 528 kg Paint horse was anesthetized for surgery of a submandibular mass. The 4‐hour anesthetic period was unremarkable. The OT tube was left in situ for the recovery. During recovery, the horse was slightly agitated and stood after three attempts. Clinical signs consistent with pulmonary edema and arterial hypoxemia (PaO₂: 5 kPa [37.5 mmHg]) subsequently developed following extubation. Respiratory signs resolved with medical therapy, including unilateral nasal oxygen insufflation, furosemide, flunixin meglumine and dimethylsulfoxide. The diagnosis of pulmonary edema in these horses was made by clinical signs and arterial blood‐gas analysis. While pulmonary radiographs were not taken to confirm the diagnosis, the clinical signs following anesthesia support the diagnosis in both cases. The etiology of pulmonary edema was most likely multifactorial.     

Hormonal profiles, behavioral responses, and short-term growth performance after castration of pigs at three, six, nine, or twelve days of age

The objective of this study was to determine the effects of castration on short-term growth performance, hormone profiles, and behavior in pigs at 3, 6, 9, or 12 d of age. Ninety intact male pigs were assigned randomly to a treatment age by litter [3, 6, 9, or 12 d of age; n = 9 to 13 pigs per treatment (age) group]. Pigs within a single litter were then assigned to noncastrated (NC) or castrated (CAS) treatment groups according to BW. Pigs were nonsurgically fitted with jugular catheters, and blood samples were drawn immediately before castration (0 h) and at 0.5, 1, 1.5, 2, 24, and 48 h after castration. Body weights were obtained when pigs were catheterized and again at 24 and 48 h after castration. Serum samples were analyzed for cortisol, porcine corticosteroid-binding globulin, and dehydroepiandrosterone sulfate (DHEA-S). No differences were detected in initial BW of pigs, and there was no overall treatment effect on growth performance of pigs at 24 or 48 h posttreatment. A time x treatment interaction was detected (P < 0.01) for serum cortisol concentrations, such that cortisol was greater in CAS pigs than in NC pigs. No overall effect of age at castration was observed on cortisol concentrations. At 24 h after castration, serum cortisol concentrations returned to baseline in all treatment groups; however, at 48 h after castration, overall cortisol concentrations were elevated (P < 0.01) in the 6-, 9-, and 12-d-old pigs in both the CAS and NC groups compared with baseline concentrations. Total cortisol and porcine corticosteroid-binding globulin were used to calculate the free cortisol index (FCI). A time x treatment interaction was observed (P < 0.01) for FCI, such that FCI was greater in CAS males than in NC males. The FCI was also affected by age (P < 0.01). There was a time x treatment x age interaction (P < 0.01) for serum DHEA-S, such that DHEA-S concentrations decreased in CAS animals but increased in NC animals, and DHEA-S concentrations increased with age. During the first 2 h after castration, there was an overall age effect (P = 0.01) on the time that pigs spent standing, such that 3-d-old pigs stood more than 6-, 9-, or 12-d-old pigs. Treatment did not influence the time that pigs spent nursing, lying, standing, or sitting, although there was a trend (P = 0.08) for CAS pigs to be less active than NC pigs. These data indicate that castration is stressful regardless of age; however, the stress associated with handling seems to increase as pigs age.     

The behavioral assessment and alleviation of pain associated with castration in beef calves treated with flunixin meglumine and caudal lidocaine epidural anesthesia with epinephrine

The objectives of this study were 1) to determine the effects of flunixin megulmine in combination with caudal epidural anesthesia as a postoperative analgesic in beef calves following surgical castration, and 2) to consider stride length and pedometry as potential behavioral assessment tools for detecting postcastration pain. Surgical castration was performed in 101 beef calves randomly assigned to 3 treatment subgroups: 1) castration without anesthesia (SURG); 2) castration following lidocaine with epinephrine caudal epidural anesthesia (SURG + EPI); 3) castration following lidocaine with epinephrine caudal epidural anesthesia and flunixin meglumine (SURG + EPI + F). Several outcomes, including pedometer counts, changes in stride length, subjective visual assessment of pain, instantaneous scan sampling of the calves’ postoperative activities, and the amount of movement and vocalization during the castration procedure, were measured to identify and quantify pain. The results indicated that stride length and the number of steps taken by calves after castration appear to be good measures of pain. Significant differences found between treatment groups for stride length and visual assessments suggest that flunixin meglumine can be considered to provide visible pain relief up to 8 hours postcastration.     

Pharmacopuncture Analgesia Using Flunixin Meglumine Injection into the Acupoint GV1 (Ho Hai) After Elective Castration in Horses

The study evaluated the effect of a 1/10 dose of flunixin meglumine administered into the governing vessel 1 (GV1) acupoint in horses that underwent castration. Twenty animals received 0.02 mg/kg detomidine intravenously, followed by 2.2 mg/kg ketamine and 0.1 mg/kg diazepam by the same route, and also a local anesthesia with 30 mL lidocaine. As postoperative analgesia, the animals received 1.1 mg/kg flunixin meglumine IV (FIV) or 0.11 mg/kg flunixin meglumine into the GV1 acupoint (FGV). Behavioral parameters were assessed 12 hours before the procedure (baseline) and at 4, 6, 12, and 24 hours after surgery; physiological parameters were measured at baseline and at 2, 4, 6, 8, 10, 12, 16, and 24 hours after surgery. The groups did not differ regarding pain scores. Heart rate was higher in the FIV group than in the FGV group 2 hours after surgery (46 ± 5.2 bpm vs. 37 ± 8.2 bpm); gut sounds decreased at 2, 4, and 6 hours in both groups. The temperature showed a decrease after 2 hours compared with baseline in the FGV group, and the systolic blood pressure was higher in the FGV group than in the FIV group at 8 hours (158 ± 18.1 mmHg vs. 134 ± 14.5 mmHg), 10 hours (157 ± 15.5 mm Hg vs. 130 ± 11.5 mmHg), and 12 hours (151 ± 18.7 mmHg vs. 134 ± 15.8 mmHg). Pharmacopuncture was as effective as conventional dose and route of flunixin meglumine in horses that underwent elective castration under those conditions.     

Effect of Meloxicam Treatment during Early Pregnancy in Holstein Heifers

We previously reported that administration of flunixin meglumine two times at a critical stage approaching pregnancy recognition associated with maintenance of the corpus luteum (CL) increased early embryo survival and pregnancy rate via an additive antiluteolytic effect with the conceptus [Vet Rec 160 (2007) 404]. In this study, the objective was to determine if a single administration of meloxicam, a non‐steroid anti‐inflammatory drug with a longer half‐life, could be used instead of flunixin meglumine. This would avoid repeated injections in heifers following insemination at a critical stage to increase pregnancy rate due to its inhibitory effect on prostaglandin F_2α synthesis. Eighty‐five, 15‐ to 18‐month‐old Holstein heifers were synchronized, and following insemination (day 0) heifers were assigned to receive subcutaneous meloxicam injection (0.5 mg/kg; n = 37) on the afternoon of day 15 or were untreated as a control (n = 48). Pregnancy rates were defined as the percentage of heifers inseminated that were diagnosed pregnant by ultrasound between days 31 and 38 after artificial insemination. Effect of the treatment on pregnancy rates was analysed by chi‐square test. Meloxicam treatment on day 15 after insemination dramatically decreased pregnancy rates in the heifers (52%; 25 of 48 in the control group vs 24.3%; 9 of 37 in the meloxicam‐treated group; p < 0.01). This result indicates that administration of meloxicam at the time associated with pregnancy recognition processes to maintain the CL was harmful to the pregnancy even though the drug is considered to be safe during pregnancy in cattle.