RESUMO
Large numbers of decapod crustacea are farmed and harvested globally for human consumption. Growing evidence for the capacity of these animals to feel pain, and therefore to suffer, has led to increased concern for their welfare, including at slaughter. In New Zealand, decapod crustacea are protected by animal welfare legislation. There is a requirement that all farmed or commercially caught animals of these species killed for commercial purposes are first rendered insensible. The aim of this study was to evaluate the efficacy of the Crustastun™, a commercially available bench-top electrical stunner, in two commercially important New Zealand crustacean species; the rock lobster (Jasus edwardsii) and koura (freshwater crayfish [Paranephrops zealandicus]). Animals were anaesthetised via intramuscular injection of lidocaine and instrumented to record the electrical activity of the nervous system, prior to being stunned according to the manufacturer's instructions. Stunning efficacy was determined by analysing neural activity and observing behaviour post stunning. All ten P. zealandicus and three J. edwardsii appeared to be killed outright by the stun. Of the remaining J. edwardsii, six exhibited some degree of muscle tone and/or slow unco-ordinated movements of the limbs or mouthparts after stunning, although there was no recovery of spontaneous or evoked movements. One J. edwardsii was unable to be stunned successfully, likely due to its very large size (1.76 kg). None of the successfully stunned animals showed any evidence of return of awareness in the five minutes following stunning. It was concluded that the Crustastun™ is an acceptable method for killing P. zealandicus and for stunning all but the largest J. edwardsii.
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This study was conducted to compare the efficacy of combinations of morphine, dexmedetomidine and maropitant in preventing the changes in electroencephalographic (EEG) indices of nociception in anaesthetized dogs subjected to a noxious electrical stimulus. In a crossover study, eight healthy adult dogs were randomly allocated to four groups: Mor: morphine 0.6 mg/kg; Dex + Mor: morphine 0.3 mg/kg + dexmedetomidine 5 µg/kg; Maro + Mor: morphine 0.3 mg/kg + maropitant 1 mg/kg; and Dex + Maro + Mor: morphine 0.2 mg/kg + dexmedetomidine 3 µg/kg + maropitant 0.7 mg/kg. Following intramuscular administration of test drugs in a minimal anaesthesia model, a supramaximal electrical stimulus (50 V at 50 Hz for 2 s) was applied and the EEG data were recorded. There were significant increases (p < .05) in the poststimulus median frequency (F50) only in groups Mor and Maro + Mor. Dex + Mor group had a significantly lower change in F50 and F95 compared to all other treatment groups. There was no correlation of the changes in EEG frequencies with blood plasma concentration of the drugs during and after noxious stimulation. Combination of dexmedetomidine and morphine was most effective in abolishing the changes in EEG indices in response to a noxious stimulus indicating a supra-additive interaction between these two drugs.
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Dexmedetomidina/farmacologia , Cães , Estimulação Elétrica , Eletroencefalografia/veterinária , Morfina/farmacologia , Quinuclidinas/farmacologia , Analgésicos não Narcóticos/administração & dosagem , Analgésicos não Narcóticos/farmacologia , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/farmacologia , Anestesia Geral/veterinária , Animais , Antieméticos/administração & dosagem , Antieméticos/farmacologia , Estudos Cross-Over , Dexmedetomidina/administração & dosagem , Morfina/administração & dosagem , Quinuclidinas/administração & dosagemRESUMO
OBJECTIVE: To evaluate analgesic efficacies of morphine and butorphanol in lame broiler chickens. STUDY DESIGN: Double blind, randomized, controlled experimental study. ANIMALS: In study 1, 36 lame and 36 sound chickens. In study 2, 48 lame and 48 sound chickens. METHODS: Sound and lame chickens were gait scored and randomly assigned into four groups: sound-drug, sound-placebo, lame-drug, and lame-placebo in study 1. In study 2, an additional lame and sound handling control group was included. Chickens in drug groups were injected with either morphine or butorphanol 2 mg kg-1 intravenously. Chickens in placebo groups were injected with an equal volume of normal saline. All birds underwent an obstacle course (OC) and latency-to-lie (LTL) test before injection and at 30 minutes and 2 hours after injection, to assess their walking ability and their standing ability. The time taken to finish the OC and the standing time in the LTL test were recorded. Friedman tests with Dunn's correction were used to identify significant differences. RESULTS: Lame chickens finished the OC faster (mean ± standard deviation 36 ± 8 c.f. 69 ± 18 seconds) after the injection of butorphanol. Morphine caused sedation with an increase in time taken to finish the OC, even in sound chickens. In the lame handling control and placebo groups the OC times increased and the LTL times decreased with each observation. CONCLUSION: Intravenous butorphanol (2 mg kg-1) may be analgesic in chickens for up to 2 hours. Morphine caused sedation.
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Analgesia/veterinária , Analgésicos Opioides , Butorfanol , Coxeadura Animal/tratamento farmacológico , Morfina , Doenças das Aves Domésticas/tratamento farmacológico , Analgesia/métodos , Animais , Galinhas , Método Duplo-Cego , Coxeadura Animal/fisiopatologia , Doenças das Aves Domésticas/fisiopatologiaRESUMO
OBJECTIVE: To compare electroencephalographic (EEG) responses of pigs to tail docking using clippers or cautery iron, performed at 2 or 20 days of age. STUDY DESIGN: Prospective, randomised controlled experimental study. ANIMALS: A total of 40 Large White x Landrace entire male pigs aged 2 (n=20) or 20 (n=20) days were randomly assigned to undergo tail docking using clippers or cautery iron. METHODS: Anaesthesia was induced and maintained with halothane delivered in oxygen. Following instrumentation, end-tidal halothane concentration was stabilised at 1.0±0.05%, and EEG recording commenced. After a 5 minute baseline period, tail docking was performed and recording continued for additional 10 minutes. EEG data were subjected to Fast Fourier transformation, yielding the summary variables median frequency (F50), 95% spectral edge frequency (F95) and total power (PTOT). Variables recorded during the baseline period were compared with those calculated at consecutive 15 second intervals following tail docking. RESULTS: Following tail docking, F50 decreased briefly but significantly in 2-day-olds, whereas 20-day-olds exhibited a sustained increase in F50 (p<0.05). Immediately after tail docking, F50 was overall lower in 2-day-olds than in 20-day-olds (p<0.05). F95 increased after docking in 20-day-olds docked using clippers (p<0.05) but did not change in 20-day-olds docked using cautery iron or in 2-day-olds docked using either method. Overall, F95 was lower in 2-day-olds than in 20-day-olds from 30 to 60 seconds after docking (p<0.05). PTOT decreased after docking in 20-day-olds (p<0.05) but did not change in 2-day-olds. Overall, PTOT was lower in 2- than in 20-day-olds during baseline and after tail docking (p<0.05). CONCLUSIONS AND CLINICAL RELEVANCE: These data suggest that tail docking using clippers is more acutely painful than docking using cautery iron and that docking within the first days of birth may be less acutely painful than docking at a later age.
Assuntos
Amputação Cirúrgica/veterinária , Eletroencefalografia/veterinária , Sus scrofa/cirurgia , Cauda/cirurgia , Amputação Cirúrgica/instrumentação , Amputação Cirúrgica/métodos , Anestesia Geral/métodos , Anestesia Geral/veterinária , Animais , Encéfalo/fisiologia , MasculinoRESUMO
OBJECTIVE: To evaluate the efficacy of oral meloxicam, topical anaesthetic cream and cautery iron in mitigating acute nociceptive responses of pigs to tail docking. STUDY DESIGN: A prospective, randomized, controlled experimental study. ANIMALS: A total of 40 healthy Large WhitexLandrace pigs aged 21±1 days, weighing 6.1±0.9 kg. METHODS: Pigs were randomly assigned to one of four treatments (n=10 per treatment): CONTROL: docked using clippers without analgesia; MEL: docked using clippers after administration of oral meloxicam; EMLA: docked using clippers after application of topical anaesthetic cream; and CAUT: docked using a cautery iron without analgesia. Anaesthesia was induced and maintained with halothane in oxygen. Following induction, end-tidal halothane was stabilized at 0.95-1.05% and electroencephalograph (EEG) recording commenced. After 5 minutes of baseline data collection, tail docking was performed and recording continued for a further 10 minutes. The EEG summary variables median frequency (F50), 95% spectral edge frequency (F95) and total power (PTOT) were calculated for the baseline period and for consecutive 30-second intervals following docking. RESULTS: Following docking, F50 increased and PTOT decreased significantly in CONTROL and MEL pigs. EMLA pigs exhibited no change in any variable, whilst CAUT pigs exhibited a reduction in PTOT but no change in F50. F50 was higher in control pigs than in EMLA pigs 30-60 seconds after docking (p≤0.01). PTOT was lower in CONTROL than in EMLA pigs 30-90 seconds after docking (p<0.03) and in CAUT pigs 60 seconds after docking (p=0.01). CONCLUSIONS AND CLINICAL RELEVANCE: Prior application of EMLA cream abolished EEG indicators of nociception in pigs docked using clippers. Docking using a cautery iron without analgesia ameliorated EEG indicators of nociception, relative to using clippers without analgesia. Prior administration of EMLA cream or the use of cautery instead of clippers may reduce the acute pain experienced by pigs undergoing tail docking.
Assuntos
Dor Aguda/veterinária , Amputação Cirúrgica/veterinária , Analgésicos , Anestesia Local/veterinária , Anestésicos Locais , Eletroencefalografia/veterinária , Sus scrofa/cirurgia , Cauda/cirurgia , Tiazinas , Tiazóis , Dor Aguda/fisiopatologia , Dor Aguda/prevenção & controle , Administração Oral , Amputação Cirúrgica/instrumentação , Amputação Cirúrgica/métodos , Analgésicos/administração & dosagem , Anestesia Local/métodos , Anestésicos Locais/administração & dosagem , Animais , Anti-Infecciosos Locais , Feminino , Masculino , Meloxicam , Tiazinas/administração & dosagem , Tiazóis/administração & dosagemRESUMO
OBJECTIVE: To investigate the mitigating effects of administration of local anaesthetic or systemic meloxicam on the electroencephalographic (EEG) and cardiovascular responses during surgical castration of Bos indicus bull calves. STUDY DESIGN: Prospective, randomized, experimental study. ANIMALS: Thirty-six 6-8 month-old Bos indicus bull calves, with a mean ± standard deviation weight of 237 ± 19 kg. METHODS: Animals were allocated randomly to three groups of 12 (group L, 260 mg of 2% lidocaine subcutaneously and intratesticularly 5 minutes prior to castration; group M, 0.5 mg kg-1 of meloxicam subcutaneously 30 minutes prior to castration; group C, no preoperative analgesia administered). Anaesthesia was induced and maintained with halothane (0.9-1.1%) in oxygen. Electroencephalogram, heart rate (HR) and mean blood pressure (MAP) were recorded for 300 seconds prior to (baseline, B) and from the start of surgery (first testicle removal, T1). HR and MAP were compared at 10 second intervals for 90 seconds from the start of T1. Median frequency (F50), spectral edge frequency (F95) and total power of the EEG (Ptot) were analysed using area under the curve comparing T1 to B. RESULTS: All EEG variables were significantly different between B and T1 (p ≤ 0.0001). No differences in F50 were found between groups during T1 (p = 0.6491). F95 and Ptot were significantly different between group L and groups C and M during T1 (p = 0.0005 and 0.0163, respectively). There were transient significant changes in HR and MAP in groups L and M compared to group C during the 20-50 second periods. CONCLUSIONS: The EEG changes indicate nociceptive responses in all three groups during surgical castration, greater in group L compared to groups C and M. Both analgesics attenuated the peracute cardiovascular response. Lidocaine and meloxicam administered prior to castration attenuated these responses in Bos indicus bull calves. CLINICAL RELEVANCE: These findings provide support for the preoperative administration of lidocaine and potentially meloxicam for castration in Bos indicus bull calves.
Assuntos
Analgesia/veterinária , Anestesia Local/veterinária , Anestésicos Locais/administração & dosagem , Bovinos/cirurgia , Eletroencefalografia/veterinária , Lidocaína/administração & dosagem , Orquiectomia/veterinária , Tiazinas/administração & dosagem , Tiazóis/administração & dosagem , Analgesia/métodos , Anestesia Local/métodos , Animais , Gasometria/veterinária , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Injeções Subcutâneas/veterinária , Meloxicam , Orquiectomia/efeitos adversosRESUMO
OBJECTIVE: Anaesthetics have differing effects on mammalian electroencephalogram (EEG) but little is known about the effects on avian EEG. This study explored how inhalant anaesthetics affect chicken EEG. STUDY DESIGN: Experimental study. ANIMALS: Twelve female Hyline Brown chickens aged 6-11 weeks. METHODS: Each chicken was anaesthetized with isoflurane, sevoflurane, and methoxyflurane. For each, anaesthesia was adjusted to 1, 1.5 and 2 times Minimum Anaesthetic Concentration (MAC). Total Power (Ptot), Median Frequency (F50), Spectral Edge Frequency (F95) and Burst Suppression Ratio (BSR) were calculated at each volume concentration. BSR data were analyzed using doubly repeated measures anova. Neither isoflurane nor sevoflurane could be included in analysis of F50, F95 and Ptot because of extensive burst suppression; Methoxyflurane data were analyzed using RM anova. RESULTS: There was a significant interaction between anaesthetic and concentration on BSR [F(4,22) = 10.65, p < 0.0001]. For both isoflurane and sevoflurane, BSR increased with concentration. Isoflurane caused less suppression than sevoflurane at 1.5 MAC and at final 1 MAC while methoxyflurane caused virtually no burst suppression. Methoxyflurane concentration had a significant effect on F50 [F(2,20) = 3.83, p = 0.04], F95 [F(2,20) = 4.03, p = 0.03] and Ptot [F(2,20) = 5.22, p = 0.02]. Decreasing methoxyflurane from 2 to 1 MAC increased F50 and F95. Ptot increased when concentration decreased from 1.5 to 1 MAC and tended to be higher at 1 MAC than at 2 MAC. CONCLUSIONS AND CLINICAL RELEVANCE: Isoflurane and sevoflurane suppressed chicken EEG in a dose-dependent manner. Higher concentrations of methoxyflurane caused an increasing degree of synchronization of EEG. Isoflurane and sevoflurane suppressed EEG activity to a greater extent than did methoxyflurane at equivalent MAC multiples. Isoflurane caused less suppression than sevoflurane at intermediate concentrations. These results indicate the similarity between avian and mammalian EEG responses to inhalant anaesthetics and reinforce the difference between MAC and anaesthetic effects on brain activity in birds.
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Anestésicos Inalatórios/farmacologia , Eletroencefalografia/veterinária , Isoflurano/farmacologia , Metoxiflurano/farmacologia , Éteres Metílicos/farmacologia , Anestesia por Inalação/veterinária , Animais , Encéfalo/efeitos dos fármacos , Galinhas , Eletrocardiografia/efeitos dos fármacos , Eletrocardiografia/veterinária , Eletroencefalografia/efeitos dos fármacos , Feminino , Coração/efeitos dos fármacos , SevofluranoRESUMO
OBJECTIVE: To describe the effects of alfaxalone on the canine electroencephalogram (EEG). STUDY DESIGN: Experimental study. ANIMALS: Eight healthy adult Huntaway dogs. METHODS: Anaesthesia was induced with propofol and maintained with halothane (0.85-0.95 end-tidal volume %) in oxygen. Animals were ventilated to maintain stable end-tidal CO(2) and halothane concentrations. Following a 30 minute stabilisation period, alfaxalone (0.5 mg kg(-1) ) was infused intravenously over a 5 minute period. The electroencephalogram was recorded from the beginning of the stabilisation period until 60 minutes following the start of alfaxalone treatment. Data were subjected to fast Fourier transformation, and median frequency, 95% spectral edge frequency and total EEG power were calculated. Two-factorial repeated measures anova (time and EEG channels were factors) was used for statistical analysis (p < 0.05). RESULTS: A shift in the dominant frequency band from beta to delta after alfaxalone treatment and occasional burst suppression were observed. Median frequency decreased significantly below baseline (9.2 ± 1.4 Hz) (mean ± SD) during alfaxalone infusion. The lowest value (4.8 ± 1.2 Hz) was recorded 5 minutes after the start of infusion. Spectral edge frequency also decreased below baseline (26.2 ± 1.5 Hz) and the lowest value (22.6 ± 1.5 Hz) also was detected at 5 minutes after the start of infusion. Total EEG power did not change significantly. In some frequencies EEG power increased soon after the start of alfaxalone infusion, then decreased below baseline later (biphasic pattern). CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone induced biphasic changes on EEG and decreased F(50) and F(95) in halothane anaesthetized dogs.
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Anestesia por Inalação/veterinária , Anestesia Intravenosa/veterinária , Anestésicos/farmacologia , Cães/fisiologia , Eletroencefalografia/veterinária , Pregnanodionas/farmacologia , Anestésicos/administração & dosagem , Anestésicos Inalatórios , Animais , Eletroencefalografia/efeitos dos fármacos , Feminino , Halotano , Masculino , Pregnanodionas/administração & dosagemRESUMO
OBJECTIVE: To report the severe metabolic acidosis identified in a group of 11 healthy mules anaesthetized with halothane for castration. STUDY DESIGN: Data generated from a prospective study. ANIMALS: Eleven mules aged 2.5-8 years, weighing 230-315 kg and 11 horses aged 1.5-3.5 years, weighing 315-480 kg. METHODS: Animals were anaesthetized for castration as part of an electroencephalographic study. Preanaesthetic medication was acepromazine (0.03 mg kg(-1) ) administered through a preplaced jugular venous catheter. Anaesthesia was induced 30-90 minutes later with intravenous thiopental (10 mg kg(-1) ). After orotracheal intubation, anaesthesia was maintained with halothane vaporised in oxygen. The animals' lungs were ventilated to maintain the end-tidal CO(2) concentration between 3.9 and 4.5 kPa (29-34 mmHg). Anaesthetic monitoring included invasive blood pressure measurement via the auricular artery (mules) and submandibular branch of the facial artery (horses). Arterial blood gas samples were drawn from these catheters at three time points during surgery and pH, PaCO(2) , base excess (ecf) and were measured. Values were compared between groups using a Mann-Whitney test. p was taken as <0.05. Results are reported as median (range). RESULTS: PaCO(2) did not differ between groups but pH was significantly lower in mules [7.178 (7.00-7.29)] compared to horses [7.367 (7.24-7.43)] (p=0.0002). values were significantly lower in the mules [16.6 (13.0-22.3) mM] compared to horses [23.7 (20.9-23.7) mM] (p=0.0001), whilst base excess (ecf) was significantly more negative in the mules [-11.4 (-1.27 to -16) mM] compared to horses [-1.3 (-5.8 to +2.4) mM] (p=0.0004). CONCLUSION AND CLINICAL RELEVANCE: This study demonstrated severe metabolic acidosis in healthy mules, which may have prompted intervention with drug therapies in a clinical arena. It is probable that the acidosis existed prior to anaesthesia and caused by diet, but other possible causes are considered.
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Acidose/veterinária , Anestesia Geral/veterinária , Anestésicos Inalatórios/efeitos adversos , Equidae , Halotano/efeitos adversos , Equilíbrio Ácido-Base/efeitos dos fármacos , Acidose/induzido quimicamente , Anestesia Geral/efeitos adversos , Animais , Gasometria/veterinária , Pressão Sanguínea/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Equidae/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Masculino , Monitorização Intraoperatória/veterinária , Orquiectomia/veterináriaRESUMO
Pain causes behavioral, autonomic, and neuroendocrine changes and is a common cause of animal welfare compromise in farm animals. Current societal and ethical concerns demand better agricultural practices and improved welfare for food animals. These guidelines focus on cattle, sheep, and pigs, and present the implications of pain in terms of animal welfare and ethical perspectives, and its challenges and misconceptions. We provide an overview of pain management including assessment and treatment applied to the most common husbandry procedures, and recommendations to improve animal welfare in these species. A cost-benefit analysis of pain mitigation is discussed for food animals as well as the use of pain scoring systems for pain assessment in these species. Several recommendations are provided related to husbandry practices that could mitigate pain and improve farm animal welfare. This includes pain assessment as one of the indicators of animal welfare, the use of artificial intelligence for automated methods and research, and the need for better/appropriate legislation, regulations, and recommendations for pain relief during routine and husbandry procedures.
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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.
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Orquiectomia/veterinária , Ovinos/cirurgia , Cauda/cirurgia , Fatores Etários , Criação de Animais Domésticos , Animais , Comportamento Animal , Masculino , Orquiectomia/psicologia , Medição da Dor/veterinária , Ovinos/psicologiaRESUMO
OBJECTIVE: To evaluate electroencephalographic (EEG) changes during ovariohysterectomy (OVH) in rats anaesthetized with halothane, and modification of the EEG changes by the co-administration of fentanyl, ketamine or thiopental. STUDY DESIGN: Prospective, randomized, blinded controlled study. ANIMALS: Sixty adult female Sprague-Dawley rats. METHODS: Anaesthesia was induced and maintained with halothane [Fe'HAL 0.95 +/- 0.05%]. The electroencephalogram was recorded continuously from the left and right primary somatosensory cortices. Rats were randomly divided into four groups and a rapid IV infusion of physiological saline, thiopental, ketamine or fentanyl was administered. OVH started 10 minutes after drug administration. Blood samples, for assay of plasma drug concentrations, were collected 5 minutes after administration and at the end of surgery. Electroencephalograph descriptors median frequency (F50), spectral edge frequency 95% (F95) and total power (P(tot)), recorded during non-surgical baseline periods, were compared with those recorded during defined surgical periods; skin incision, right and left ovarian pedicle ligation; cervical ligation. Plasma drug concentrations were measured using high performance lipid chromatography. RESULTS: Although a large number of statistical differences in EEG data were observed, these generally represented a reduction in F50 or F95 throughout the experimental recording period and were similar between groups. A significant reduction in P(tot) occurred during ligation of the ovaries and cervix in the control group compared with other recording periods. The co-administration of ketamine, fentanyl and thiopental obtunded the reduction in P(tot). CONCLUSIONS AND CLINICAL RELEVANCE: Electroencephalographic changes, in the control group, mimicked changes reported in other studies using the minimal anaesthesia model. However, the stability in F50 during the surgical period compared with the baseline period indicated that OVH is an unsuitable surgical stimulus to investigate EEG changes with noxious stimulation. This may be attributed to the relatively prolonged duration of this surgical procedure and the primarily visceral afferent sensory innervation of the genital tract.
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Anestésicos Inalatórios , Eletroencefalografia/veterinária , Halotano , Histerectomia/veterinária , Ovariectomia/veterinária , Anestésicos Combinados , Animais , Feminino , Fentanila , Hipnóticos e Sedativos , Ketamina , Ratos , Ratos Sprague-Dawley , TiopentalRESUMO
The objective of this study was to identify risk factors for morbidity and mortality of bobby calves across the whole dairy supply chain in New Zealand. A case-control study was carried out in the 2016 spring calving season. A total of 194 bobby calves, comprising 38 cases (calves that died or were condemned for health or welfare reasons before the point of slaughter) and 156 controls (calves deemed acceptable and presented for slaughter) were included in the study. Case and control calves were selected by veterinarians located at 29 processing premises across New Zealand. Information regarding management of selected calves on-farm, during transport and at the processor was obtained retrospectively via questionnaires administered to supplying farmers, transport operators and processing premises personnel. Associations between management variables and calf mortality (death or condemnation) were examined using multivariable logistic regression models. Factors associated with an increased risk of calf mortality included time in the farm of origin's calving season, duration of travel from farm to the processor and processing slaughter schedule (same day or next day). Every additional week into the farm's calving season increased the odds of mortality by a factor of 1.2 (95%CI 1.06, 1.35). Similarly, each additional hour of travel time increased the odds of mortality by a factor of 1.45 (95% CI 1.18, 1.76). Risk of mortality was significantly greater for calves processed at premises with a next day slaughter schedule than those processed at premises with a same day slaughter schedule (OR 3.82, 95% CI 1.51, 9.67). However, when the data set was limited to those cases that died or were condemned in the yards (i.e. excluding calves that were dead or condemned on arrival) the effect of same day slaughter was not significant. In order to reduce bobby calf mortality and morbidity, transport duration should be kept as short as possible and a same day slaughter schedule applied. While these factors can be regulated, New Zealand's pastoral dairy system means that calves will inevitably be transported for slaughter across several months each spring. Although farm management factors did not apparently influence the risk of mortality in this study, the effect of time in farm's calving season suggests there may be farm-management related factors that change over the season. This requires further investigation.
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Doenças dos Bovinos/mortalidade , Indústria de Laticínios , Animais , Estudos de Casos e Controles , Bovinos , Morbidade , Mortalidade , Nova Zelândia/epidemiologia , Fatores de RiscoRESUMO
OBJECTIVE: To compare the effects of morphine, parecoxib, tramadol and a combination of parecoxib, tramadol and pindolol on nociceptive thresholds in awake animals and their effect on glomerular filtration rate (GFR) in dogs subjected to 30 minutes of anesthesia. ANIMALS: Eight adult mixed breed experimental dogs. STUDY DESIGN: Randomized, controlled trial. METHODS: Dogs received 0.05 mg kg(-1) acepromazine subcutaneously (SC) as anaesthetic pre-medication. Thirty to sixty minutes later, they received either tramadol 3 mg kg(-1) intravenously, (IV), parecoxib (1 mg kg(-1) IV), a combination of tramadol 3 mg kg(-1) (IV), parecoxib 1 mg kg(-1) (IV) and pindolol 5 microg kg(-1) (SC), morphine (0.1 mg kg(-1) (IV) or 0.9% saline (2 mL). Anaesthesia was then induced with IV propofol to effect (2.9 +/- 0.8 mg kg(-1)) and maintained with halothane in oxygen for 30 minutes. Systolic arterial blood pressure was maintained above 90 mmHg with IV fluids and by adjusting the inspired halothane concentration. Post-treatment nociceptive thresholds to mechanical stimuli, expressed as percent of pre-treatment values, were compared between the treatments to assess the analgesic efficacy of the drugs. Plasma iohexol clearance (ICL), a measure of GFR, was estimated both before and 24 hours after induction of anaesthesia to study the drugs' effects on renal perfusion. Nociceptive threshold and GFR data were compared using mixed model analysis in SAS 9.1. RESULTS: Both tramadol and parecoxib produced similar analgesia, which was less than that of morphine. Their combination with pindolol produced analgesia comparable with morphine. None of the test drugs, either alone or in combination, reduced GFR. CONCLUSION: Tramadol and parecoxib (either alone or in combination) can increase nociceptive thresholds in awake dogs and have minimal effects on renal perfusion in normotensive dogs subjected to anaesthesia.
Assuntos
Analgésicos/administração & dosagem , Analgésicos/efeitos adversos , Cães , Taxa de Filtração Glomerular/veterinária , Analgésicos/farmacologia , Anestesia Intravenosa/veterinária , Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/farmacologia , Animais , Taxa de Filtração Glomerular/efeitos dos fármacos , Isoxazóis/administração & dosagem , Isoxazóis/efeitos adversos , Isoxazóis/farmacologia , Morfina/administração & dosagem , Morfina/efeitos adversos , Morfina/farmacologia , Pindolol/administração & dosagem , Pindolol/efeitos adversos , Pindolol/farmacologia , Tramadol/administração & dosagem , Tramadol/efeitos adversos , Tramadol/farmacologiaRESUMO
OBJECTIVES: To characterize changes in the cerebro-cortical response of lambs to rubber-ring castration during the first 6 weeks of postnatal life. ANIMALS: Coopworth-Texel cross ram lambs between 3 hours and 44 days of age. METHODS: The electroencephalogram (EEG) and heart rate responses to rubber ring castration were compared. Anaesthesia was induced via a face mask and maintained with halothane in oxygen (e'(Hal) = 1.2%). Once a stable plane of anaesthesia had been achieved, data collection of EEG and electrocardiogram (ECG) commenced, and the lambs were castrated 15 minutes later, using rubber rings. Heart rate was derived from the ECG and the median frequency (F(50)), spectral edge frequency (F(95)) and total power (p(tot)) were derived from the EEG. RESULTS: Castration-induced changes in F(50) increased from 2 +/- 1.8% in the youngest lambs to a maximum of 33 +/- 8.9% in the 36 +/- 0.5 day-old lambs. Changes in F(95) increased from -7 +/- 3% in the youngest lambs to a maximum of 16 +/- 11% in the 36 +/- 0.5 day-old lambs. Linear regression analysis in lambs up to 10 days of age demonstrated a change in the response with age that was significantly different from zero for F(50) (r(2) = 0.28, p = 0.007) and F(95) (r(2) = 0.38, p = 0.001), but not for p(tot) or heart rate. CONCLUSION: This study identified significant changes in the responsiveness of the lambs' cerebral cortex to the noxious stimulation of castration over the first 7-10 days of postnatal life. The results suggest that mechanisms that suppress responses of the fetus to noxious stimulation may still be active in the first few days after birth. CLINICAL RELEVANCE: This study documents changes in central nociceptive processing which may reflect the ability of neonatal animals to perceive pain.
Assuntos
Envelhecimento/fisiologia , Anestésicos Inalatórios/farmacologia , Eletroencefalografia/efeitos dos fármacos , Halotano/farmacologia , Orquiectomia/veterinária , Ovinos/fisiologia , Anestesia por Inalação/veterinária , Animais , Masculino , Medição da Dor/veterináriaRESUMO
OBJECTIVE: To investigate whether percentage changes in pulse wave transit time (PWTT%Δ) induced by mini-fluid challenges predict fluid responsiveness in mechanically ventilated anesthetized dogs. DESIGN: Prospective experimental trial. SETTING: University teaching hospital. ANIMALS: Twelve Harrier hounds. INTERVENTION: Each dog was anesthetized with propofol and isoflurane after premedication with acepromazine, mechanically ventilated, and had a fluid challenge. This was repeated 4 weeks later. The fluid challenge, 10 mL/kg of colloid administration over 13 minutes, consisted of 3 intermittent mini-fluid challenges (1 mL/kg of each over a minute) with a minute interval, and the remaining colloid administration (7 mL/kg) over 7 minutes. MEASUREMENTS AND MAIN RESULTS: Percentage change in velocity time integral of pulmonary arterial flow by echocardiography was calculated as an indication of change in stroke volume. Fluid responsiveness was defined as percentage change in velocity time integral ≥ 15% after 10 mL/kg colloid. Dogs responded on 14 fluid challenges and did not on 10. After 1, 2, 3, and 10 mL/kg of fluid challenge, PWTT%Δ1, 2, 3, 10 were measured. Receiver operator characteristic (ROC) curves were generated and areas under ROC curve were calculated for PWTT%Δ1, 2, 3 . A gray zone approach was used to identify the clinically inconclusive range. The area under the ROC curve for PWTT%Δ3 was 0.91 (P = 0.001). Cutoff value for PWTT%Δ3 was -2.5% (sensitivity: 86%, specificity: 90%). The gray zone for PWTT%Δ3 was identified as between -2.9% to -1.9% for which fluid responsiveness could not be predicted reliably in 6 out of 24 fluid challenges. CONCLUSIONS: In mechanically ventilated anesthetized dogs given a mini-fluid challenge of 3 mL/kg of colloid, PWTT%Δ could predict fluid responsiveness although the gray zone should be considered.
Assuntos
Cães/fisiologia , Hidratação/veterinária , Hemodinâmica/fisiologia , Análise de Onda de Pulso/veterinária , Respiração Artificial/veterinária , Anestesia/veterinária , Animais , Ecocardiografia/veterinária , Feminino , Humanos , Masculino , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Volume SistólicoRESUMO
BACKGROUND: Nonsteroidal antiinflammatory drugs and N-methyl-D-aspartate (NMDA) receptor antagonists reduce pain hypersensitivity when given by the intrathecal (i.t.) route, but their combined effects have hardly been studied. We assessed the effects of the nonsteroidal antiinflammatory drug ketoprofen and the NMDA receptor channel blocker ketamine, given alone and in combination, on mechanical nociceptive thresholds in sheep implanted with indwelling cervical i.t. catheters. METHODS: Sheep were given, by i.t. catheter, ketoprofen (200-3200 microM; 100 microL) and ketamine (25-400 microM; 100 microL) alone or in combination (837.95-3350.78 microM; 100 microL; 0.955:0.045 proportion). They also received NMDA (2 mM; 100 microL) preceded by the highest concentration of ketoprofen and ketamine alone or in combination. Saline solution (0.9%; 100 microL) and xylazine (1.95 mM; 100 microL) were used as negative and positive controls, respectively. RESULTS: Xylazine significantly increased the area under the nociceptive threshold versus time curve values (AUC) for 30, 60, and 180 min posttreatment. Ketoprofen and ketamine, alone and in combination, produced no significant effect on AUC values. NMDA alone decreased the AUC value for 30 min posttreatment. This pain hypersensitivity was prevented by preadministering ketoprofen and ketamine alone and in combination. CONCLUSIONS: In sheep, i.t. administration of ketoprofen and ketamine, alone or together, produced no hypoalgesia; however, they prevented NMDA-induced mechanical hypersensitivity. Ketoprofen and ketamine may have therapeutic potential in conditions associated with persistent pain.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Ketamina/administração & dosagem , Cetoprofeno/administração & dosagem , N-Metilaspartato/toxicidade , Dor/prevenção & controle , Animais , Feminino , Injeções Espinhais , Ovinos , Xilanos/farmacologiaRESUMO
The reliable assessment and management of avian pain is important in the context of animal welfare. Overtly expressed signs of pain vary substantially between and within species, strains and individuals, limiting the use of behaviour in pain studies. Similarly, physiological indices of pain can also vary and may be confounded by influence from non-painful stimuli. In mammals, changes in the frequency spectrum of the electroencephalogram (EEG) recorded under light anaesthesia (the minimal anaesthesia model; MAM) have been shown to reliably indicate cerebral responses to noxious stimuli in a range of species. The aim of the current study was to determine whether the MAM can be applied to the study of nociception in birds. Ten chickens were lightly anaesthetised with halothane and their EEG recorded using surface electrodes during the application of supramaximal mechanical, thermal and electrical noxious stimuli. Spectral analysis revealed no EEG responses to any of these stimuli. Given that birds possess the neural apparatus to detect and process pain, and that the applied noxious stimuli elicit behavioural signs of pain in conscious chickens, this lack of response probably relates to methodological limitations. Anatomical differences between the avian and mammalian brains, along with a paucity of knowledge regarding specific sites of pain processing in the avian brain, could mean that EEG recorded from the head surface is insensitive to changes in neural activity in the pain processing regions of the avian brain. Future investigations should examine alternative electrode placement sites, based on avian homologues of the mammalian brain regions involved in pain processing.
Assuntos
Galinhas/fisiologia , Eletroencefalografia , Anestesia/veterinária , Animais , Encéfalo/fisiologia , Estimulação Elétrica , Eletrocardiografia , Feminino , Frequência Cardíaca/fisiologia , Dor/patologiaRESUMO
OBJECTIVE: To evaluate whether pulse pressure variation (PPV) and pleth variability index (PVI) are more accurate than central venous pressure (CVP) for predicting fluid responsiveness in mechanically ventilated isoflurane-anesthetized dogs after premedication with acepromazine. DESIGN: Prospective experimental trial. SETTING: University teaching hospital. ANIMALS: Twelve Harrier hound dogs. INTERVENTIONS: Each dog was anesthetized and had a fluid challenge performed. This was repeated 4 weeks later for a total of 24 fluid challenges. After premedication with intramuscular acepromazine, anesthesia was induced with propofol and maintained with isoflurane. The dogs were mechanically ventilated with constant settings. The fluid challenge consisted of 10 mL/kg of 6% hydroxyethyl starch intravenously over 13 minutes. MEASUREMENTS AND MAIN RESULTS: Before and after the fluid challenge, PPV, PVI, CVP, and other hemodynamics were recorded. Change in velocity time integral of pulmonary arterial blood flow by echocardiography was calculated as an indication of change in stroke volume. A fluid responder was defined as an increase in velocity time integral ≥ 15%. Receiver operator characteristic (ROC) curves were used to determine cutoff values. Areas under ROC curve were calculated and compared. Dogs responded on 14 fluid challenges and did not on 10. Cutoff values for PPV and PVI were 11% (sensitivity 79%; specificity 80%) and 9.3% (sensitivity 86%; specificity 70%), respectively. The areas under the ROC curve of PPV [0.85, 95% confidence interval (CI): 0.70-1.00, P = 0.038] and PVI (0.84, 95% CI: 0.68-1.00, P = 0.043) were significantly higher than CVP (0.56, 95% CI: 0.32-0.81). CONCLUSIONS: PPV and PVI predicted fluid responsiveness more accurately than CVP and may be useful to guide fluid administration in mechanically ventilated isoflurane-anesthetized dogs after premedication with acepromazine.
Assuntos
Anestésicos Inalatórios/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Cães/fisiologia , Hemodinâmica/efeitos dos fármacos , Isoflurano/farmacologia , Artéria Pulmonar/fisiologia , Anestesia/veterinária , Anestésicos Inalatórios/administração & dosagem , Animais , Feminino , Hidratação/veterinária , Isoflurano/administração & dosagem , Masculino , Pletismografia/veterinária , Estudos Prospectivos , Artéria Pulmonar/diagnóstico por imagem , Curva ROC , Respiração Artificial/veterinária , Sensibilidade e EspecificidadeRESUMO
Little is known about the effects of inhalant anaesthetics on the avian electroencephalogram (EEG). The effects of halothane on the avian EEG are of interest, as this agent has been widely used to study nociception and analgesia in mammals. The objective of this study was to characterize the effects of halothane anaesthesia on the EEG of the chicken. Twelve female Hyline Brown chickens aged 8-10 weeks were anaesthetized with halothane in oxygen. For each bird, anaesthesia was progressively increased from 1-1.5 to 2 times the Minimum Anesthetic Concentration (MAC), then progressively decreased again. At each concentration, a sample of EEG was recorded after a 10-min stabilization period. The mean Total Power (PTOT ), Median Frequency (F50) and 95% Spectral Edge Frequency (F95) were calculated at each halothane MAC, along with the Burst Suppression Ratio (BSR). Burst suppression was rare and BSR did not differ between halothane concentrations. Increasing halothane concentration from 1 to 2 MAC resulted in a decrease in F50 and increase in PTOT , while F95 increased when MAC was reduced from 1.5 to 1. The results indicate dose-dependent spectral EEG changes consistent with deepening anaesthesia in response to increasing halothane MAC. As burst suppression was rare, even at 1.5 or 2 times MAC, halothane may be a suitable anaesthetic agent for use in future studies exploring EEG activity in anaesthetized birds.