An investigation of the effects of intratesticular alfaxalone and lidocaine during castration in piglets

Objective

To determine whether intratesticular injection of an alfaxalone–lidocaine combination can induce anesthesia and provide a rapid recovery in piglets undergoing surgical castration.

Comparison of intratesticular injection of zinc gluconate versus surgical castration to sterilize male dogs

OBJECTIVE: To compare castration of dogs by use of intratesticular injection of zinc gluconate with traditional surgical procedures in terms of acceptance by pet owners, ease of use, and short-term outcomes on Isabela Island of the Galápagos Islands. ANIMALS: 161 privately owned male dogs admitted to a neuter program. PROCEDURES: Medical records of male dogs neutered during a 4-week animal control campaign were reviewed to collect information regarding signalment, method of castration, complication rate, and treatment outcomes. RESULTS: Of the 161 dogs admitted for castration, 58 were surgically castrated and 103 were treated with zinc gluconate. Dogs were returned to their owners for observation following castration. Wound dehiscence occurred in 2 skin incisions, representing 3.4% of the 58 dogs that underwent bilateral orchiectomy. Necrotizing zinc-gluconate injection-site reactions occurred in 4 dogs receiving injection volumes near the maximum label dose (0.8 to 1.0 mL), representing 3.9% of the zinc-gluconate procedures. Surgical wound complications were treated by superficial wound debridement and resuturing, in contrast to zinc-gluconate injection-site reactions, which all required orchiectomy and extensive surgical debridement, including scrotal ablation in 2 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Low cost, ease of use, and cultural acceptance of a castration technique that does not require removal of the testes make zinc gluconate a valuable option for large-scale use in dogs, particularly in remote locations lacking sophisticated clinical facilities or skilled surgeons and staff. Further investigation is needed to identify risk factors in dogs for adverse reactions to zinc gluconate and to develop strategies for avoidance.     

Comparison of intraoperative pain responses following intratesticular or mesorchial injection of lidocaine in standing horses undergoing laparoscopic cryptorchidectomy

OBJECTIVE: To compare pain responses in stallions undergoing standing laparoscopic cryptorchidectomy following intratesticular or mesorchial infiltration of lidocaine. DESIGN: Clinical trial. ANIMALS: 20 stallions with 1 or 2 undescended testes. PROCEDURES: Standing horses were administered a nonsteroidal anti-inflammatory drug and a caudal epidural injection of detomidine hydrochloride and underwent laparoscopic cryptorchidectomy. The undescended testis (1/horse) was grasped to determine the preoperative pain response (present vs absent) and assess severity of pain (by use of a visual analog scale [VAS]). The undescended testis or its mesorchium was injected with 2% lidocaine (10 mL); saline (0.9% NaCl) solution (10 mL) was injected in the untreated structure. Presence and severity of pain was determined by 2 individuals as the testis was grasped following infiltration and at the times of ligature placement and transection of the spermatic cord. Serum cortisol concentration was analyzed preoperatively, after ligation, and after transection. Presence or absence of signs of pain, severity of pain, and serum cortisol concentrations were compared within and between treatment groups. RESULTS: Detection of signs of pain and VAS pain scores did not differ between observers at any time point. Perceived pain responses associated with ligature placement differed significantly from preoperative responses. Pain responses and serum cortisol concentrations after intratesticular and mesorchial infiltration of lidocaine did not differ. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that intratesticular or mesorchial infiltration of lidocaine combined with administration of a nonsteroidal anti-inflammatory drug and caudal epidural injection of detomidine provides adequate analgesia in standing stallions undergoing laparoscopic cryptorchidectomy.     

Effect of marbofloxacin on cardiovascular variables in healthy isoflurane-anesthetized dogs

OBJECTIVE: To study the hemodynamic effects of marbofloxacin (MBF) in isoflurane-anesthetized dogs. ANIMALS: 6 healthy 8-month-old Beagles. PROCEDURE: Anesthesia was induced with sodium thiopental and maintained with isoflurane. Cardiovascular variables were monitored throughout anesthesia. Marbofloxacin was administered by an IV bolus at 2 mg/kg, followed 10 minutes later by an infusion at a rate of 40 mg/kg/h for 30 minutes (total dose, 20 mg/kg). Plasma MBF concentrations were measured by high-performance liquid chromatography. RESULTS: The mean peak concentration during MBF infusion was 34.2 +/- 6.4 microg/mL. The IV administration of the MBF bolus did not alter any cardiovascular variable in isoflurane-anesthetized dogs. Significant changes were found during infusion when a cumulative dose of 12 mg/kg had been given. The maximal decreases observed at the end of the infusion were 16% in heart rate, 26% in systolic left ventricular pressure, 33% in systolic aortic pressure, 38% in diastolic aortic pressure, 29% in cardiac output, and 12% in QT interval. All dogs recovered rapidly from anesthesia at the end of the experiment. CONCLUSIONS AND CLINICAL RELEVANCE: MBF may safely be used at 2 mg/kg IV in isoflurane-anesthetized dogs, and significant adverse cardiovascular effects are found only when 6 to 8 times the recommended dose is given.     

Castration of piglets: the analgesic effects of intratesticular and intrafunicular lidocaine injection

OBJECTIVE: The aim of this study was to evaluate the analgesic effect of intratesticular and intrafunicular lidocaine for the surgical castration of piglets and to investigate the degree of nociception induced by lidocaine injection. STUDY DESIGN: Prospective controlled experimental study. ANIMALS: Forty-seven male Norwegian landrace piglets with normal testicular anatomy, aged 22 (+/-2.6 SD) days and weighing 7.4 +/- 1.4 kg. MATERIALS AND METHODS: Anaesthesia was induced and maintained using halothane delivered in oxygen. End-tidal halothane was stabilized at 1.3% for 20 minutes before mean arterial blood pressure (MAP) pulse rate and electroencephalography (EEG) monitoring began. After 5 minutes of data collection, scrotal skin was desensitized with lidocaine before either an intrafunicular (IF) (n = 15) or an intratesticular (IT) (n = 16) lidocaine injection was made. Pigs in the control group (n = 16) did not receive lidocaine. Ten minutes later, a scalpel and an emasculator were used to cut the funiculus spermaticus. The MAP, pulse rate and EEG were monitored continuously for 5 minutes after castration. RESULTS: During castration, MAP increased significantly, while pulse rate and EEG theta power fell significantly more in control, compared with the IT or IF groups. EEG alpha power fell more in the control group than in the IF group. No significant differences were found between the IF and IT groups. EEG, MAP and pulse rate responses to castration in the control group were significantly larger than the response to lidocaine injection. CONCLUSION/CLINICAL RELEVANCE: Injecting lidocaine into the funiculus spermaticus or into the testes is effective in reducing signs of nociception caused by castration. Lidocaine injection is less noxious than castration without local anaesthetic.     

Intratesticular lidocaine reduces the response to surgical castration in dogs

ObjectiveTo investigate whether intratesticular injection of lidocaine pre-surgery would reduce the intraoperative responses to elective castration in dogs.Study designDouble-blinded, randomized, controlled, prospective clinical study.AnimalsForty-two client-owned dogs weighing 2.2–38.4 kg and aged between 4.5 and 56 months.MethodsGroup L dogs received an intratesticular injection of 2% lidocaine (2 mg kg^?1) and Group S an identical volume of saline prior to surgery. Premedication was with acepromazine and morphine intramuscularly. Anaesthesia was induced with propofol intravenously and maintained with isoflurane vaporized in oxygen. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (f_R), end-tidal isoflurane (Fe′ISO) and carbon dioxide concentrations, oxygen saturation and ECG were monitored during surgery. Fe′ISO was maintained at 1.0 ± 0.1%. Supplemental propofol was given in response to gross movement.ResultsGroup L had significantly lower maximum values for both HR and MAP. Group L displayed significantly smaller increases in HR during exteriorization of the first testis than Group S. There was an overall significant difference in MAP between groups during all surgical events (p = 0.041) and time points (p = 0.002). In univariate analysis, Group L showed significantly less changes in MAP during skin incision, exteriorization of the first testis and clamping of both spermatic cords. Group S reached its highest f_R significantly earlier. Group L (eight dogs) required additional propofol 33 ± 18 minutes after the start of surgery and Group S (seven dogs) at 19 ± 17 minutes; this difference was not statistically significant. Seven dogs in Group L and 12 dogs in Group S required rescue analgesia with morphine (GCMPS-SF score ≥6); this difference was not statistically significant. No adverse effects were reported postoperatively.Conclusions and clinical relevanceBased on this study, the authors recommend the use of intratesticular lidocaine for surgical castration in dogs.     

Clinical safety of intratesticular transplantation of allogeneic bone marrow multipotent stromal cells in stallions

Although stem cell therapy is a promising alternative for treatment of degenerative diseases, there are just few reports on the use of stem cells therapy in horse's reproductive system. This study aims to evaluate the effect of intratesticular injection of bone marrow mesenchymal stromal/stem cells (MSCs) in healthy stallions, and its outcome on seminal parameters and fertility. In Experiment 1, 24 stallions were divided into treatment group (TG) and control group (CG). In the TG, an intratesticular application of MSC was performed, and in the CG, only PBS was used. Measurements of testicular volume, surface temperature and Doppler ultrasonography were performed 24 and 48 hr after treatments. Fifteen days after application, the testicles were removed and submitted to histological analysis. In Experiment 2, 3 fertile stallions received similarly treatment with MSCs. Physical examination and sperm analysis were performed weekly during 60 days after treatment, and at the end, semen from one of them was used for artificial inseminations of 6 healthy mares. In Experiment 1, clinical examinations showed no signals of acute inflammation on both groups according to the analysed variables (p > .05). Also, no signal of chronic inflammation was observed on histological evaluation. In Experiment 2, stallions presented no physical alterations or changes in sperm parameters, and a satisfactory fertility rate (83%; 5/6) was observed after AI. The results support the hypothesis that intratesticular application of bone marrow MSCs is a safe procedure, and this could be a promising alternative to treat testicular degenerative conditions.     

Effect of butorphanol administration on cardiovascular parameters in isoflurane-anesthetized horses - a retrospective clinical evaluation.

OBJECTIVE: To determine cardiovascular responses to administration of butorphanol in isoflurane-anesthetized horses. STUDY DESIGN: Retrospective evaluation of anesthetic records. ANIMALS: Seventy-six horses anesthetized for a variety of clinical surgical procedures. METHODS: Anesthetic records of clinical equine patients anesthetized between January 1999 and December 2003 were searched. The records were reviewed for horses in which anesthesia was induced with ketamine and a benzodiazepine and maintained with isoflurane, and horses that received butorphanol intraoperatively. Exclusion criteria included horses in which the rate of infusion of an inotrope or end-tidal isoflurane concentration was changed 10 minutes before or after the butorphanol bolus. The horses were separated into two groups: group 1 horses received butorphanol at intervals as part of a balanced protocol, group 2 horses had > or = 10% increase in heart rate (HR) or blood pressure within 10 minutes prior to butorphanol administration. RESULTS: Eighty-nine butorphanol administration events matched the criteria for inclusion, 49 in group 1 and 40 in group 2. There were no significant changes after butorphanol administration in systolic arterial pressure (SAP), mean arterial pressure (MAP), diastolic arterial pressure (DAP), and heart rate (HR) in group 1, or in end-tidal carbon dioxide concentration or hemoglobin oxygen saturation in either group. There were significant decreases in SAP (p < 0.0001), MAP (p < 0.0005), and DAP (p < 0.0008) after butorphanol administration in group 2. CONCLUSIONS AND CLINICAL RELEVANCE: The results presented here confirm that butorphanol can be administered to horses during isoflurane anesthesia without adverse effects on HR and arterial blood pressure. The results imply that butorphanol can deepen the plane of anesthesia and obtund sympathetic stimulation from a surgical procedure.     

Cardiopulmonary responses to experimentally induced gastric dilatation in isoflurane-anesthetized dogs.

Gastric dilatation was experimentally induced in 6 anesthetized dogs maintained with constant-dose isoflurane in oxygen. An intragastric balloon was used to distend the stomach with a constant 30 mm of Hg pressure for 3.5 hours. The PaCO2 was maintained between 35 and 45 mm of Hg, using intermittent positive-pressure ventilation. Cardiopulmonary measurements prior to stomach distension (baseline) were compared with measurements taken during 0.1, 0.5, 1.0, 1.5, 2.5, and 3.5 hours of stomach distension by analyzing the change from baseline in a randomized-block analysis with each dog as a block. After distending the stomach, cardiac index increased (P less than 0.01) from 1.5 to 3.5 hours. Stroke volume did not change, thus the increase in the cardiac index was attributable to an increase in heart rate. During inflation, increases were observed in systemic arterial, pulmonary arterial, and right atrial pressure. Respiratory frequency was unchanged; however, to maintain PaCO2 constant, it was necessary to progressively increase peak airway pressure. Although PaO2 tended to decrease during gastric dilation, the dogs were never hypoxemic. These results indicate that when our methods are used to maintain a constant anesthetic dose of isoflurane in oxygen, an observed increase in cardiovascular performance is expected. This differs from other studies in anesthetized dogs that have shown reduction in cardiovascular performance following gastric dilatation.     

Assessment of the hemodynamic effects of lidocaine administered IV in isoflurane-anesthetized cats

OBJECTIVE:To determine the hemodynamic effects of lidocaine (administered IV to achieve 6 plasma concentrations) in isoflurane-anesthetized cats. ANIMALS: 6 cats. PROCEDURE: Cats were anesthetized with isoflurane in oxygen (end-tidal isoflurane concentration set at 1.25 times the predetermined individual minimum alveolar concentration). Lidocaine was administered IV to each cat to achieve target pseudo-steady-state plasma concentrations of 0, 3, 5, 7 9, and 11 microg/mL, and isoflurane concentration was reduced to an equipotent concentration. At each plasma lidocaine concentration, cardiovascular and blood gas variables; PCV; and plasma total protein, lactate, lidocaine, and monoethylglycinexylidide concentrations were measured in cats before and during noxious stimulation. Derived variables were calculated. RESULTS: n isoflurane-anesthetized cats, heart rate, cardiac index, stroke index, right ventricular stroke work index, plasma total protein concentration, mixed-venous PO2 and hemoglobin oxygen saturation, arterial and mixed-venous bicarbonate concentrations, and oxygen delivery were significantly lower during lidocaine administration, compared with values determined without lidocaine administration. Mean arterial pressure, central venous pressure, pulmonary artery pressure, systemic and pulmonary vascular resistance indices, PCV, arterial and mixed-venous hemoglobin concentrations, plasma lactate concentration, arterial oxygen concentration, and oxygen extraction ratio were significantly higher during administration of lidocaine, compared with values determined without lidocaine administration. Noxious stimulation did not significantly affect most variables. CONCLUSIONS AND CLINICAL RELEVANCE: In isoflurane-anesthetized cats, although IV administration of lidocaine significantly decreased inhalant requirements, it appeared to be associated with greater cardiovascular depression than an equipotent dose of isoflurane alone. Administration of lidocaine to reduce isoflurane requirements is not recommended in cats.     

Pharmacokinetics of lidocaine and its active metabolite, monoethylglycinexylidide, after intravenous administration of lidocaine to awake and isoflurane-anesthetized cats

OBJECTIVE: To describe the pharmacokinetics of lidocaine and its active metabolite, monoethylglycinexylidide (MEGX), after i.v. administration of a single bolus of lidocaine in cats that were awake in phase 1 and anesthetized with isoflurane in phase 2 of the study. ANIMALS: 8 healthy adult cats. PROCEDURE: During phase 1, cats were administered lidocaine (2 mg/kg, i.v.) as a bolus injection (time 0). During phase 2, cats were anesthetized with isoflurane and maintained at 0.75 times the minimum alveolar concentration of isoflurane for each specific cat. After a 15-minute equilibration period, lidocaine (2 mg/kg, i.v.) was administered as a bolus injection to each cat (time 0). In both phases, plasma concentrations of lidocaine and MEGX were measured at various time points by use of liquid chromatography-mass spectrometry. RESULTS: Anesthesia with isoflurane significantly decreased the volume of the central compartment, clearance, and elimination half-life of lidocaine and significantly increased the extrapolated plasma drug concentration at time 0, compared with values for awake cats. Pharmacokinetics of MEGX were also changed by isoflurane-induced anesthesia because the maximum observed plasma concentration (C(max)), area under the concentration-time curve extrapolated to infinity, and time to C(max) were significantly higher in anesthetized cats, compared with values for awake cats. CONCLUSIONS AND CLINICAL RELEVANCE: Pharmacokinetics of lidocaine and MEGX were substantially altered in cats anesthetized by use of isoflurane. When pharmacokinetic variables are used to determine loading and infusion doses in awake or anesthetized cats, they should be measured in cats that are awake or anesthetized, respectively.     

Neuromuscular and cardiovascular effects of atracurium in isoflurane-anesthetized chickens.

Atracurium besylate, a nondepolarizing neuromuscular blocking agent, was administered to 24 isoflurane-anesthetized domestic chickens. Birds were randomly assigned to 4 groups, and atracurium was administered at dosage of 0.15, 0.25, 0.35 or 0.45 mg/kg of body weight. The time of onset of twitch depression, the amount of maximal twitch depression, and the duration of muscular relaxation were recorded. After return to control twitch height, atracurium was further administered to achieve > 75% twitch depression. When twitch depression reached 75% during noninduced recovery, 0.5 mg of edrophonium/kg was administered to reverse the muscle relaxation. Throughout the experimental period, cardiovascular, arterial blood gas, and acid-base variables were monitored. The effective dosage of atracurium to result in 95% twitch depression in 50% of birds, (ED95/50) was calculated, using probit analysis, to be 0.25 mg/kg, whereas the ED95/95, the dosage of atracurium to result in 95% twitch depression in 95% of birds, was calculated by probit analysis to be 0.46 mg/kg. The total duration of action at dosage of 0.25 mg/kg was 34.5 +/- 5.8 minutes; at the highest dosage (0.45 mg/kg), total duration increased to 47.8 +/- 10.3 minutes. The return to control twitch height was greatly hastened by administration of edrophonium. Small, but statistically significant changes in heart rate and systolic blood pressure, were associated with administration of atracurium and edrophonium. These changes would not be clinically relevant. In this study, atracurium was found to be safe and reliable for induction of muscle relaxation in isoflurane-anesthetized chickens.     

Effect of pre-medication on gastroduodenoscopy in isoflurane-anesthetized cats

The pre‐medicant chosen may influence the ease with which gastroduodenoscopy (GD) is performed. The purpose of this study was to evaluate the relative ease of GD in cats under ketamine and isoflurane anesthesia after IM injection of hydromorphone (H, 0.1 mg kg^?1), hydromorphone plus glycopyrrolate (HG, 0.1 mg kg^?1 (H), 0.01 mg kg^?1 (G)), medetomidine (M, 0.03 mg kg^?1), or butorphanol (B, 0.4 mg kg^?1). Eight cats were assigned randomly to receive each treatment in a cross‐over design with at least 7 days between treatments. Twenty minutes after pre‐medication, medetomidine produced greater (p = 0.001) sedation than the other treatments when assessed, using a subjective ordinal scale. The cats were injected with ketamine (10 mg kg^?1 IM), orotracheally intubated, connected to a pediatric circle breathing system, and allowed to spontaneously breathe isoflurane in oxygen. Once end‐tidal isoflurane concentration was stable at 1.4% for 15 minutes, endoscopy was started. A single endoscopist (REG), who was unaware of the treatment used, performed all endoscopies. The endoscopist scored the difficulty of endoscopy subjectively (0–3). The significance of differences between treatments was evaluated using Friedman's test. Time for entering the stomach was 9.4 (4.7–15.9) (median (minimum–maximum)), 6.6 (5.2–11.7), 8.4 (6.3–16.5), and 7.7 (5.1–14.7) seconds and for entering the duodenum from the stomach was 20.5 (13.8–40.9), 18.2 (10.3–39.8), 20.2 (16.2–119.5), and 22.2 (11.8–83.8) seconds for H, HG, M, and B treatments, respectively. There were no significant differences in the time for, or difficulty of, endoscopy. We conclude that any of these drugs can be used satisfactorily at the doses and combinations tested to pre‐medicate cats prior to general anesthesia for GD.     

Effect of blocking vision and olfaction on sexual responses of haltered or loose stallions

Ten stallions were used in a modified split-plot design involving four treatments and two handling methods. Treatments were: a) vision and olfaction not blocked; b) vision blocked, olfaction not blocked; c) vision not blocked, olfaction blocked; and d) vision and olfaction blocked. The methods of handling were: a) stallions turned loose in teasing area, and b) stallions handled on a lead shank. Stallions teased four estrous mares, four diestrous mares and four geldings. Criteria for evaluation of stallion behavior was duration of investigation (sec), of area as well as various portions of the stimulus animal's anatomy, and other pre-copulatory sexual behaviors (Table 1) in duration and frequency. Except for area investigation and no investigation, there were more frequent or longer responses when vision was not blocked compared to blocked (P<0.05). Events associated with display of flehmen and mounting activity were lower (P<0.05) when vision was blocked. Handling a stallion on a lead shank, while teasing, resulted in 23 longer or more frequent pre-copulatory sexual behaviors than when the stallions were loose. There were more frequent or longer (P<0.05) behavioral responses when stallions were handled on a lead shank and olfaction was not blocked. Events such as duration and number of flehmen responses were lower (P<0.05), and time of no investigation was longer (P<0.001) when olfaction was blocked. There was no difference (P>0.05) in the time spent inyestigating estrous mares, diestrous mares or geldings, except for number of flehmen responses. Number of flehmen responses to estrous mares was higher (P<0.05) than to diestrous mares, while number of flehmen responses to diestrous mares was higher (P<0.001) than to geldings. Blocking olfaction did not decrease frequency or duration of sexual behaviors as much as blocking vision (P<0.05), resulted in decreased (P<0.05) flehmen responses. Blocking vision significantly decreased (P<0.05) teasing behaviors, duration of erection, flehmen, and number of mounts regardless of stimulus animal. Stallions utilized visual stimuli to a greater extent than olfactory stimuli. Handling stallions on a lead shank appeared to enhance expression of precopulatory behavior compared to when the stallions were loose.     

Effect of hyperlipidemia on cardiovascular responses to adrenergic stimulation in piglets.

This study was designed to assess the effect of hyperlipidemia on cardiovascular responses to adrenergic stimulation in a porcine model. Four-week-old piglets (n = 10) were divided into two groups; one fed a control diet and the other was fed an atherogenic diet for 8 weeks. Cardiovascular responses were evaluated to both norepinephrine (NE; 0.5 and 2.5 micrograms/kg) and isoproterenol (ISO; 0.1 and 0.5 microgram/kg) from simultaneous recordings of femoral arterial pressure, heart rate, left intraventricular pressure and left intraventricular dP/dt. It was found that no significant difference in the baseline values of cardiovascular function was observed between the control and hyperlipidemic groups. However, in the hyperlipidemic group as compared with the control group: 1) arterial blood pressure responses to NE were significantly increased (P less than 0.05), 2) cardiac contractile responses to NE and ISO were significantly potentiated (P less than 0.05), and 3) reflex bradycardia in response to increasing arterial blood pressure did not occur. These findings indicate that hyperlipidemia can potentiate the cardiovascular responses to adrenergic stimulation, whereas reflex cardiovascular regulation is somewhat altered by hyperlipidemia. Conceivably, these observations may have relevance to the possible role of the mechanism of the interaction of hyperlipidemia and hypertension in atherogenesis.     

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.     

Intratesticular and subcutaneous lidocaine alters the intraoperative haemodynamic responses and heart rate variability in male cats undergoing castration

ObjectiveTo evaluate the usefulness of intratesticular and subcutaneous lidocaine in alleviating the intraoperative nociceptive response to castration, measured by pulse rate (PR) and mean arterial pressure (MAP), and to test the applicability of heart rate variability (HRV) analysis in assessing this response.Study designRandomized, controlled, observer-blinded experimental trial.AnimalsThirty-nine healthy male cats admitted for castration.MethodsOne group received general anaesthesia and served as control group (GA), while the treatment group (LA) additionally received local anaesthesia (lidocaine 2 mg kg^?1) intratesticularly and subcutaneously. PR and MAP were recorded at anaesthesia baseline (T0), treatment (T1), incision left testicle (T2), traction on spermatic cord (T3), tightening of the autoligature and resection of the cord (T4), incision on the right side (T5), traction on spermatic cord (T6), and tightening of the autoligature and resection of cord (T7). HRV analysis was divided into three 5-minute intervals: baseline (H0), treatment (H1), and surgery (H2).ResultsThere were significant increases in PR and MAP for both groups during surgery from T3 onwards; however, the increase in the treatment group (LA) was significantly lower than for the control group (GA). For HRV analysis, significant differences were found between groups in the following parameters during surgery: TP (total power), VLF (very low frequency), SDNN (standard deviation of NN intervals [=the interval between two consecutive R-waves in the ECG]), and TI (triangular index), which were lower in the LA group. Mean NN was significantly lower in the GA group, whereas LF (low frequency) and LFn (low frequency, normalized value) were lower in the LA group. HF (high frequency) and HFn (high frequency, normalized value) decreased significantly from H1 to H2 in both groups.Conclusions and clinical relevanceThe study showed that the nociceptive response to surgery was alleviated by the use of intratesticular and subcutaneous lidocaine and that HRV analysis is a promising research tool to estimate intraoperative nociception in cats during general anaesthesia.