Chez les animaux de laboratoire, même si les anesthésiques par inhalation sont généralement plus sécuritaires que les injectables, leur utilité est souvent restreinte lorsqu’un protocole expérimental exige une autre approche. Des combinaisons d’anesthésiques contenant de la kétamine sont considérées comme l’option de choix pour les anesthésies injectables chez les rats. Le vieillissement entraîne des changements dégénératifs au niveau de la structure et la fonction des organes, modifiant souvent à la pharmacocinétique des drogues. Ce projet porte sur l’évaluation des changements pharmacodynamiques (physiologiques, biochimiques et histologiques) et pharmacocinétiques, lors d’une combinaison anesthésique de kétamine-­‐xylazine chez le rat Sprague-­‐Dawley vieillissant. Une anesthésie à la kétamine-­‐xylazine fut induite chez des rats Sprague-­‐Dawley de différents âges. Afin d’évaluer l’effet du vieillissement sur le métabolisme des deux drogues, des prélèvements sanguins périodiques pour l’analyse de la pharmacocinétique ainsi que des mesures des paramètres physiologiques, biochimiques et une histopathologie furent effectués. Le vieillissement a causé certaines modifications notamment en produisant une diminution de la saturation d’oxygène, une baisse marquée de la fréquence cardiaque et respiratoire, une hypoalbuminémie ainsi qu’une augmentation de la durée d’anesthésie. Les paramètres pharmacocinétiques de la kétamine et de la xylazine furent grandement affectés par le vieillissement causant une augmentation progressive significative de l’aire sous la courbe (AUC) et du temps de demi-­‐vie, ainsi qu’une diminution de la clairance. À la lumière de ces résultats, les doses de kétamine et de xylazine doivent être adaptées chez les rats vieillissants pour permettre une anesthésie de durée raisonnable et un réveil sans complications. / In laboratory animals, even if inhalation anesthetics are generally safer than injecting, their usefulness is often restrained when an experimental design does not allow it. For this reason, ketamine combinations are considered the option of choice for injecting anesthesia in rats. Aging brings degenerative changes in the structure and function of the organs, often affecting the pharmacokinetics of drugs. This project focuses on the evaluation of physiological, pharmacokinetic, biochemical and histological changes during a ketamine-­‐xylazine anesthetic combination in aging Sprague-­‐Dawley rats. Anesthesia with ketamine-­‐xylazine was induced in Sprague-­‐Dawley rats of different ages. To assess the effect of aging on the metabolism of both drugs, periodic blood samples for pharmacokinetic analysis and measurements of physiological, biochemical and histological parameters were performed. Aging have made some changes for example a decrease in oxygen saturation, a sharp drop in heart and respiratory rate, hypoalbuminemia and an increase in the duration of anesthesia. The pharmacokinetic parameters of ketamine and xylazine were greatly affected in older animals, causing a significant increase in the area Under the curve (AUC) and the half-­‐life time, and a decrease in clearance. In the light of these results, dosage of ketamine and xylazine must be adapted in aging rats to allow a short anesthesia and an awakening without complications.

Lorsque l’anesthésie par inhalation ne peut être utilisée chez le rat, la combinaison de kétamine et de xylazine est l’alternative la plus fréquemment utilisée. Les doses administrées peuvent varier selon le protocole expérimental. En présence de fièvre, d’infections ou de processus tumoral accompagné de fièvre, la pharmacocinétique de ces drogues peut être modifiée. Ce projet porte sur l’évaluation des changements physiologiques, hématologiques, biochimiques et pharmacocinétiques chez le rat Sprague Dawley lors d’anesthésie avec le mélange kétamine-xylazine suite à l’administration de trois doses différentes de lipopolysaccharide (LPS). Après l’administration de LPS, une anesthésie à la kétamine-xylazine fut induite chez des rats Sprague Dawley. Des prélèvements sanguins périodiques ainsi que des mesures des paramètres physiologiques furent effectués afin d’évaluer l’effet du LPS sur la pharmacocinétique des deux drogues ainsi que sur les paramètres biochimiques et hématologiques. Les différentes doses de LPS ont causé certaines modifications notamment en produisant une baisse marquée de la saturation en oxygène et de l’albumine sérique, une augmentation de la durée d’anesthésie ainsi que des lésions hépatiques mineures. Les paramètres pharmacocinétiques de la kétamine furent peu altérés par l’administration de LPS tandis qu’une diminution de la clairance et une augmentation de l’aire sous la courbe (AUC) furent observées pour la xylazine dans les groupes ayant reçu les doses moyenne et élevée de LPS. Ces résultats montrent que les doses de xylazine doivent être adaptées en présence de LPS pour permettre une anesthésie de courte durée et des changements physiologiques et biochimiques moindres lorsqu’elle est administrée avec de la kétamine. / When inhalation anesthesia cannot be used in laboratory rats, ketamine-xylazine combination is the most frequent alternate regimen. The administrated doses can vary according to the experimental protocol. During fever episodes, infections or tumoral process, the pharmacokinetics of these drugs can be modified. This project focuses on the evaluation of the physiological, hematological, biochemical and pharmacokinetics changes in Sprague Dawley rats during ketamine-xylazine anesthesia, after administration of three different doses of lipopolysaccharide (LPS). After administration of LPS to Sprague Dawley rats, ketamine-xylazine anesthesia was induced. Periodic blood samplings and monitoring of physiologic parameters were made in order to evaluate the effect of LPS on ketamine-xylazine pharmacokinetics and hematological and biochemical parameters. The different LPS doses caused specific parameter modifications including a marked decrease of oxygen blood saturation and serum albumin, a longer anesthesia duration and minor hepatic lesions. No significant modifications of pharmacokinetics parameters of ketamine were observed. An increase of area under curve (AUC) and a decrease of xylazine clearance were noted in groups who received medium and large doses of LPS. These results show that that xylazine doses need to be adapted in the presence of LPS, to allow a shorter duration anaesthesia and lesser physiological and biochemical changes when administered with ketamine.

Présentement, le diagnostic d’otite moyenne-interne chez le veau est basé sur la présence de signes cliniques appropriés ainsi que les tests diagnostiques tels que la radiographie et la tomodensitométrie. L’objectif de cette étude prospective était d’évaluer les valeurs prédictives de l’examen neurologique, l’examen otoscopique et le test des potentiels auditifs évoqués (PAE) dans le diagnostic d’otite moyenne-interne chez le veau, en utilisant la tomodensitométrie comme test standard. Le deuxième objectif était de définir les valeurs de référence pour le PAE chez le veau normal et d’en décrire les anomalies chez des veaux atteints d’otite moyenne-interne. Dix-sept veaux de race Holstein entre 5-7 semaines d’âge ont été inclus. Tous les veaux ont eu un examen neurologique, un examen otoscopique et une évaluation des PAEs. Les veaux ont été tranquillisés avec de la xylazine intraveineuse (0,05-0,15mg/kg) pour la tomodensitométrie des bulles tympaniques afin d’évaluer pour la présence d’otite moyenne-interne. Selon les résultats de la tomodensitométrie, 11 des 17 veaux étaient atteints avec otite moyenne, 4 de façon unilatérale et 7 bilatéralement. Cinq ondes ont été identifiées de façon constante sur les tracés des PAEs des 6 veaux normaux. Les valeurs positives prédictives pour le PAE, l’examen neurologique et l’examen otoscopique étaient 94,7%, 91,7% et 66,7% respectivement. D’un point de vue clinique, le test le plus fiable dans le diagnostic d’otite moyenne-interne chez le veau est le PAE. Les anomalies ont été observées au PAE avant le développement des signes neurologiques chez certains veaux. / Currently, the antemortem diagnosis of otitis media-interna is based upon the presence of appropriate clinical signs and adjunctive diagnostic imaging including radiography and computed tomography. The purpose of this prospective study was to evaluate predictive values of neurological examination, otoscopic examination and BAER in calves for the diagnosis of otitis media-interna using computed tomography as the gold standard. The second objective was to define BAER reference values in normal calves and to describe BAER abnormalities in calves affected with otitis media-interna. Seventeen Holstein calves between 5 and 7 weeks of age were included. All calves had a neurological examination, otoscopic examination and BAER. Calves were sedated with intravenous xylazine (0.05-0.15 mg/kg [0.02-0.07 mg/lb]) for computed tomography of the tympanic bullae to evaluate for the presence of otitis media-interna. Based upon computed tomographic results, 11 of 17 calves were affected with otitis media, 4 unilaterally and 7 bilaterally. Five waveforms were consistently identified on BAER traces from 6 normal calves. The positive predictive value of BAER, neurological examination and otoscopic examination were 94.7%, 91.7% and 66.7% respectively. Clinically, the most reliable non-invasive diagnostic test to diagnose otitis media-interna in the calf is the BAER. Abnormalities were observed on BAER before the development of neurological deficits in approximately 40% of calves allowing earlier diagnosis.

The endangered Arabian oryx, Oryx leucoryx faces a wide range of issues that potentially have adverse effects on their welfare while they are free-ranging in their natural habitat, housed in captivity for conservation breeding or when they are translocated from the wild to captivity or vice versa. Furthermore, the global increase in the number of captive Arabian oryx (currently more than 95 % of the world population of about 8000 individuals), gives rise to particular concern for their welfare and health within captive conditions. Thorough assessment of the welfare of animals involves physiological and behavioural measures. Methods for assessment of welfare in Arabian oryx have not been established and the present studies aim at establishing physiological tools for assessment of welfare. Therefore, the present studies developed and applied new methods for non-invasive assessment of welfare in the Arabian oryx (using faecal samples), and established reference values for a range of haematological, biochemical and clinical parameters. The potential disturbances in these parameters were investigated after immobilisation and tranquillisation and post- transportation. Two enzyme immuno-assays (EIA I and II) for faecal glucocorticoid metabolites (FGM) were validated by stimulation and suppression of the hypothalamic-pituitary-adrenal axis through injection of synthetic adrenocorticotropic hormone (ACTH) and dexamethasone, respectively. These studies established a lag-time of 14 ± 1 h between secretion of glucocorticoids into the blood stream and excretion of the measured FGM. Faecal incubation at 30°C for 3 days showed that EIA I measured more stable faecal glucocorticoid metabolites than EIA II, and has greater potential for application in field conditions. This method was found to be invaluable for measuring stress and hence assessment of welfare status, and its use is recommended in planning welfare improvements. Measurement of FGM successfully detected the stress of road transportation (630 km for 8-10 h), showing an increase 2 days after transport, followed by recovery to basal FGM levels after re-housing for up to 11 days. Releasing oryx to the wild, in Oman, and tracking for 11 days, after transportation 50-70 km from the captive site (Arabian Oryx Sanctuary, Jaaluni), caused an increase in FGM to the highest levels seen in these studies, and suggests a high level of stress was experienced after release of oryx. Published reference values for haematological, biochemical, hormonal and clinical parameters for Arabian oryx are limited, with little information for non-immobilised and non-tranquillised oryx or consideration of possible age and sex differences. Therefore, reference values and inter-percentile ranges (2.5 and 97.5 percentiles) were established for 32 parameters, in separate groups of male and female adult oryx, without using immobilising or tranquillising chemicals during capture. The haematological parameters investigated were white blood cell count and differentiation (%) of cell types (neutrophils, lymphocytes, monocytes, eosinophils, basophils), number of platelets, red blood cell count, haemoglobin concentration and haematocrit, erythrocyte cell volume, erythrocyte haemoglobin content and concentration, serum osmolality and ions (sodium, potassium, chloride, calcium, magnesium and phosphorus). Biochemical parameters investigated were serum urea, glucose, total protein, albumin and plasma lactate concentrations. Clinical parameters investigated were body temperature, heart and respiratory rates. Hormonal parameters measured were cortisol, free-thyroxine, free-triiodothyronine and insulin concentrations. Near basal values for serum cortisol were measured in Arabian oryx sampled within 2 min, while values were significantly higher in oryx sampled within 5-10 min. The reference values established in these studies are considered valuable tools for diagnosis of disease and physiological alterations in male and female Arabian oryx. To investigate the possible effects of the common practice of immobilisation and tranquillisation on physiological and biochemical status, two restraint chemicals (xylazine and perphenazine enanthate) were evaluated. Xylazine (an immobilising agent) caused changes in many clinical, hormonal, haematological and biochemical parameters; respiratory rate decreased by 74 %, heart rate decreased by 58 %, causing a decrease in red blood cell count, haemoglobin concentration and haematocrit, serum albumin and total protein concentration. Xylazine also induced a decrease in serum insulin, which probably caused the observed increase in serum glucose. Perphenazine enanthate (a long-acting tranquilliser) was found to have no adverse effects on most parameters, which generally remained in the reference ranges. However, a reduction in blood haematocrit and related parameters (red blood cell count and plasma haemoglobin concentration) occurred, 1-3 days after injection. The tranquilliser also plays a role in reducing stress and significantly reduced serum cortisol 2-3 days after injection in oryx held in captivity compared to oryx that received a saline (control) injection. FGM increased significantly one day after injection of perphenazine enanthate and saline, suggesting the animals were initially stressed by the handling and venipuncture, taking into consideration the lag-time from cortisol secretion to appearance of FGM. The baseline concentration of serum cortisol was used in assessing the stress caused by handling before and after transporting Arabian oryx for 630 km (8-10 h) and the acute effects of handling and injections. Increased serum cortisol was always associated with leukocytosis, neutrophilia and lymphopenia. Serum cortisol of non-transported oryx was reduced by the tranquilliser perphenazine enanthate, but transportation of tranquillised Arabian oryx during hot ambient temperature (maximum 42 °C) resulted in fatigue and prevented reaching a clear conclusion of the role of the tranquilliser in reducing transport stress. Non-tranquillised oryx transported at a maximum of 26-30 °C showed a similar level of stress as implied by the level of faecal glucocorticoid metabolites, but without fatigue. However, the tranquilliser induced calmness in Arabian oryx for up to 7 days, which facilitated capture and handling. Therefore, perphenazine enanthate has a potential to be used in the management practices, such as movement and transport of Arabian oryx. This thesis discusses the current and future welfare issues that face Arabian oryx in captivity, upon release and in the wild. Additional methods are proposed for thorough assessment and improvement of welfare to complement the methods established by the present studies.

Orientador: Carlos Augusto Araújo Valadão / Banca: Paulo Sérgio Patto dos Santos / Banca: Anderson Farias / Resumo: Foram avaliados os efeitos cardiovasculares e comportamentais após a administração intravenosa de amitraz ou xilazina em oito gatos. Todos os animais foram submetidos aos três tratamentos, a saber: GXil - 1 mg/kg de xilazina; GAmz - 1 mg/kg de amitraz em diluente lipídico; e GDil - volume de diluente lipídico idêntico ao utilizado nos animais tratados com amitraz, respeitando-se um intervalo mínimo de 15 dias entre eles. Imediatamente antes dos tratamentos, avaliaram-se à pressão arterial sistólica (PAS), temperatura retal (T), freqüência respiratória (f), ritmo, freqüência (FC), índice (IC) e contratilidade cardíaca. Os demais registros foram realizados aos 5, 10, 15, 20, 30, 40, 50 e 60 minutos após os tratamentos. Empregou-se análise de variância (ANOVA) de uma única via e teste de Friedman, ambos seguidos pelo teste de Tukey (p=0,05), respectivamente para os dados paramétricos e não-paramétricos. Tanto o amitraz como a xilazina causaram bloqueios atrioventriculares de 1º grau e redução da FC, frações de ejeção (FE) e de encurtamento (FS), IC, PAS e T. Complexos ventriculares prematuros foram observados após a aplicação de amitraz ou do diluente, e a f aumentou. O amitraz induziu sedação menos intensa do que a xilazina. Conclui-se que ambos induzem bradicardia e BAV de 1º grau, observando-se maior depressão da contratilidade cardíaca para a xilazina. A dose empregada do amitraz produz efeito sedativo em gatos. / Abstract: To evaluate the cardiovascular and behavioral alterations, eight cats were submitted to amitraz or xylazine intravenous injection: GXil - 1 mg/kg of xylazine; GAmz - 1 mg/kg of amitraz; and GDil - diluent in equal volume used on GAmz. The same cats were used after a 15 day interval. Systolic arterial blood pressure (SAP), temperature (T), respiratory (RR) and heart rates (HR), cardiac index (CI), rhythm and contractility (ejection fraction - EF and shortening fraction - SF) were measured before treatments and 5, 10, 15, 20, 30, 40, 50 and 60 minutes after each treatment. One way analysis of variance (ANOVA) and Friedman test, followed by Tukey test (p=0.05), were used to compare parametric and non-parametric data, respectively. Amitraz and xylazine induced first-degree A-V block, decreased HR, EF, SF, CI, SAP and T. Ventricular premature complexes were noted after amitraz or diluent injection, and RR increased. Amitraz induced a lower sedative effect compared to xylazine. It was concluded that both a2-agonists produce bradycardia and first-degree A-V block, but xylazine causes greater cardiac contractility depression. Additionally, amitraz produces a sedative effect in cats. / Mestre

Orientador: Carlos Augusto Araújo Valadão / Banca: Paulo Sérgio Patto dos Santos / Banca: Carmen Esther Grumadas Machado / Resumo: Avaliaram-se, 8 equinos, sob anestesia geral inalatoria com isofluorano (1CAM) e infusao continua de xilazina (0,35mg/kg/h) ou medetomidina (3,5£gg/kg/h), em relacao a frequencia cardiaca, ritmo cardiaco, frequencia respiratoria, pressao arterial, hemogasometria arterial, tonus muscular e temperatura, nos tempos T0 (imediatamente antes do inicio da infusao continua) e T10 ao T60 (intervalos de 10 minutos, apos inicio da infusao continua), alem da qualidade da tranquilizacao, inducao e recuperacao anestesica. Os dados parametricos foram submetidos a analise de variancia para repeticoes multiplas, seguido pelo teste de Student-Newman-Keuls e, entre os grupos, teste-t de Student. Para os dados nao parametricos utilizou-se teste de Friedman e entre os grupos, teste de Mann-Whitney (p-T0,05). Houve reducao da frequencia cardiaca e da temperatura e elevacao da pressao arterial media. A paCO2 (no GM) e a ctCO2 elevaram-se e a paO2 mostrou-se maior no GM que no GX. Os dois farmacos mostraram-se eficientes para tranquilizacao, mas o GM demonstrou melhor miorrelaxamento e qualidade de inducao anestesica que o GX. Da mesma forma, a recuperacao anestesica apresentada pelo GM foi de melhor qualidade, embora mais prolongada. Conclui-se que a infusao continua de doses equipotentes de xilazina e medetomidina, durante anestesia geral inalatoria, com isofluorano, em equinos, promove alteracoes cardiocirculatorias, respiratorias e hemogasometricas discretas e equivalentes. / Abstract: Eight equines under inhalatory general anesthesia with isoflurane (1MAC) and continuous infusion of xylazine (0.35mg/kg/h) or medetomidine (3.5-Êg/kg/h) were evaluated for heart rate and rhythm, respiratory rate, arterial blood pressure, arterial blood gas analysis, muscle relaxation and temperature immediately before the beginning of the continuous infusion (T0) and in intervals of 10 minutes after the beginning of the continuous infusion (T10 to T60) and also for tranquillization, induction and anesthetic recovery quality. The parametric data were evaluated by one way repeated measures ANOVA, followed by Student-Newman-Keuls and between groups Student t-test. Non-parametric data were evaluated by Friedman test and between groups Mann-Whitney test (p.0.05). Heart rate and temperature decreased and mean Heart rate and temperature decreased and mean aaarrrttteeerrriiiaaalll ppprrreeessssssuuurrreee increased. PaCO2 (in GM) and ctCO2 increased and GM showed a higher paO2 than GX. Both drugs were efficient in tranquilization but GM showed better muscle relaxation and induction quality than GX. In the same way, GM presented better anesthetic recovery even though it took more time. We conclude that equipotent doses of continuous infusion of medetomidine and xylazine during inhalatory general anesthesia with isoflurane in equines promote slight and equivalent cardiocirculatory, respiratory and arterial blood gases changes. / Mestre

Orientador: Frederico Ozanam Papa / Resumo: RESUMO A indução farmacológica da ejaculação é uma alternativa utilizada para aumentar a função ejaculatória de garanhões incapazes de ejacularem pelos métodos tradicionais de coleta de sêmen. No entanto, os protocolos desenvolvidos até o presente momento apresentam baixas taxas de sucesso na indução da ejaculação, alta variabilidade de doses, vias de administração e efeitos adversos. A ocitocina é um hormônio que participa ativamente no desencadeamento da ejaculação, no entanto, não existem estudos avaliando sua atuação em protocolos de indução farmacológica da ejaculação. Nesse sentido, o presente estudo teve por objetivos: 1) Comparar a eficiência de diferentes protocolos na indução da ejaculação; 2) A IX - Imipramina (3/mg/kg/v.o) + xilazina (0,66/mg/kg/i.v); IXO - Imipramina (3/mg/kg/v.o) + xilazina (0,66/mg/kg/i.v) + ocitocina (20UI/i.v); D- detomidina (0,02/mg/kg/i.v); DO - detomidina (0,02/mg/kg/i.v) + ocitocina (20 UI/i.v); ID-Imipramina (3mg/kg/ v.o) + detomidina (0,02mg/kg/i.v); IDO-Imipramina (3mg/kg/v.o) + detomidina (0,02mg/kg/i.v) + ocitocina (20 UI/i.v); IO- Imipramina (3mg/kg/v.o) + ocitocina (20 UI/i.v). xiv ocitocina quando adicionada aos protocolos; 3) Comparar os parâmetros seminais de ejaculados coletados em vagina artificial e por indução farmacológica da ejaculação. Foram avaliados os protocolos X - Xilazina (0,66/ valiar a eficiência da mg/kg/i.v); XO - xilazina (0,66/mg/kg/i.v) + ocitocina (20UI/i.v); Nenhum... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The pharmacological induction of ejaculation has been an alternative used to increase ejaculatory function of stallions incapable of ejaculating by the traditional methods of semen collection. However, the protocols developed to date are available in high rate of dose variation, routes of administration, adverse effects and ejaculation rates. In general, pharmacological protocols have shown low success rates in inducing ejaculation. Thus, the aims of the study were: 1) Compare the efficiency of different protocols to induce ex copula ejaculation when detomidine and oxytocin was added to the protocols; 2) Compare seminal parameters between in copula and ex copula ejaculates; We evaluated the nine protocols to ex copula ejaculation: X - xylazine (0.66mg/kg/ i.v); XO - xylazine + oxytocin (20UI/i.v); IX - imipramine (3mg/kg/v.o) + xylazine (0.66mg/kg/i.v); IXO - imipramine (3mg/kg/v.o) + xylazine (0.66 mg/kg/i.v) + oxytocin (20UI); D - detomidine (0.02mg/kg/i.v); DO - detomidine (0.02mg/kg/i.v) + oxytocin (20UI/i.v); ID - imipramine (3mg/kg/v.o) + detomidine (0.02mg/kg/i.v); IDO- imipramine (3mg/kg/v.o) + detomidine (0.02mg/kg/i.v) + oxytocin (20 UI/ i.v); IO- imipramine (3mg/kg/v.o) + oxytocin (20 UI/i.v). Four young stallions (2-3 y old) and 12 sexually mature stallions (6 to 26 y old) were each submitted to 2 treatment trials conducted at 3-day intervals. Induced ejaculates were collected into a plastic bag and compared with in copula ejaculates. None of the 4 young stallions... (Complete abstract click electronic access below) / Mestre

The α₂-adrenergic receptor agonists are widely used in equine practice, especially in antalgic therapy, because they promote profound sedation and moderate visceral analgesia. The opioids are used in horses with some restriction due to the excitatory effects in this specie. The objective of this study was to evaluate the sedative effect, hemodynamic, pulmonary and digestory changes due to the neuroleptoanalgesic association of buprenorphine and different doses of xylazine. Six adults horses of both gender, weighting an average of 400 Kg. The animals were control of themselves, being divided into four groups, control group (CG) saline NaCl 0,9% solution administrated IV, and three other groups with buprenorphine 10 μg/kg associated to three different doses of xylazine, 0,25 mg/kg (BX25), 0,50 mg/kg (BX50) and 0,75 mg/kg (BX75) IV. Sedative effects, gastrointestinal motility, FC, f, SAP, MAP, DAP, blood gas tension analysis and core temperature were evaluated 30 min before, immediately before the administration of any treatment for basal values and after 5, 15 and every 15 min until 120 min post-treatment. Gastrointestinal motility was evaluated by the same period and for 12 hours, every 2 hours. Blood samples were collected at 0, 30 and 60 min. Parametric variables were analyzed with ANOVA, followed by Dunnett test for intra group and Tukey test between groups. For the non-parametric variable (intestinal motility) Wilcoxon test was used. Differences was considered significant when P<0.05. Intense sedative effect was observed in the three groups with the neuroleptoanalgesic association lasting 45 min in BX75 with profound ataxia. Intestinal motility decreased with 5 minutes after administration and remained decreased for 8 hours. Hemodynamic parameters started to increased after 30 min and no changes were observed in respiratory frequency and blood gas samples analysis, only HCO3- showed increase. Synergistic effect was observed, maintaining hemodynamic stability, with minimal pulmonary effects. The hypomotility observed must be considered when the association is used in horses with gastrointestinal disorders. / Os agonistas α₂-adrenérgicos são amplamente empregados na clínica equina, destacando-se na terapia antálgica pela intensa sedação e por produzirem moderada analgesia visceral. Os opióides, apesar de serem utilizados na terapia antálgica de equinos, parecem ainda ter seu uso relativamente restrito, principalmente pela excitação observada quando da utilização destes. O estudo teve como objetivo investigar o efeito sedativo e as alterações hemodinâmicas, pulmonares e digestória decorrentes da utilização da associação neuroleptoanalgésica entre a buprenorfina e diferentes doses de xilazina. Utilizou-se 6 equinos de ambos os sexos, com média de peso de 400kg. Os animais foram divididos em quatro grupos autocontrole, sendo grupo controle, administração de solução fisiológica 0,9% IV, e outros três grupos, com a associação de buprenorfina 10 μg/kg associada a diferentes doses de xilazina, 0,25 mg/kg (BX25), 0,5 mg/kg (BX50) e 0,75 mg/kg (BX75) IV. Avaliouse a atividade sedativa, motilidade intestinal, FC, f, PAS, PAM, PAD, parâmetros hemogasométricos e temperatura corpórea aos 30 min antes, imediatamente antes da administração de qualquer substância para determinação dos valores basais e aos 5min, 15 min, e a cada 15 min até 120 min após o tratamento. A motilidade intestinal foi avaliada pelo mesmo período nos mesmos tempos e a cada duas horas até 12 horas após a administração. Os parâmetros hemogasométricos foram avaliados aos 0, 30 e 60 min. Para as variáveis paramétricas utilizou-se análise de variância para amostras pareadas, com posterior teste de Dunnett. Para comparações entre os grupos, realizou-se análise de variância, seguido de teste de Tukey. Para a variável não-paramétrica, motilidade intestinal, utilizou-se teste de Wilcoxon para amostras pareadas. As diferenças foram consideradas significantes quando P<0,05. Foi observado efeito sedativo significante nos três grupos com a associação neuroleptoanalgésica, perdurando por até 45 min no BX75 com severa ataxia. Observou-se hipomotilidade 5 minutos após a administração perdurando por 480 min. Os parâmetros hemodinâmicos elevaram-se após os 45 min, não sendo observadas alterações na frequência respiratória e nos parâmetros hemogasométricos, ocorrendo aumento somente no HCO3-. Conclui-se que houve efeito sinérgico entre os dois fármacos, mantendo estabilidade hemodinâmica, com mínimas alterações pulmonares. A hipomotilidade promovida pela associação deve ser considerada quando usada em equinos com distúrbios gastrintestinais.

Made available in DSpace on 2014-06-11T19:23:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-10-20Bitstream added on 2014-06-13T20:28:10Z : No. of bitstreams: 1 doria_rgs_me_jabo.pdf: 844929 bytes, checksum: 66ab2b4d51e336752ba5ac561a267860 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Avaliaram-se, 8 equinos, sob anestesia geral inalatoria com isofluorano (1CAM) e infusao continua de xilazina (0,35mg/kg/h) ou medetomidina (3,5£gg/kg/h), em relacao a frequencia cardiaca, ritmo cardiaco, frequencia respiratoria, pressao arterial, hemogasometria arterial, tonus muscular e temperatura, nos tempos T0 (imediatamente antes do inicio da infusao continua) e T10 ao T60 (intervalos de 10 minutos, apos inicio da infusao continua), alem da qualidade da tranquilizacao, inducao e recuperacao anestesica. Os dados parametricos foram submetidos a analise de variancia para repeticoes multiplas, seguido pelo teste de Student-Newman-Keuls e, entre os grupos, teste-t de Student. Para os dados nao parametricos utilizou-se teste de Friedman e entre os grupos, teste de Mann-Whitney (p-T0,05). Houve reducao da frequencia cardiaca e da temperatura e elevacao da pressao arterial media. A paCO2 (no GM) e a ctCO2 elevaram-se e a paO2 mostrou-se maior no GM que no GX. Os dois farmacos mostraram-se eficientes para tranquilizacao, mas o GM demonstrou melhor miorrelaxamento e qualidade de inducao anestesica que o GX. Da mesma forma, a recuperacao anestesica apresentada pelo GM foi de melhor qualidade, embora mais prolongada. Conclui-se que a infusao continua de doses equipotentes de xilazina e medetomidina, durante anestesia geral inalatoria, com isofluorano, em equinos, promove alteracoes cardiocirculatorias, respiratorias e hemogasometricas discretas e equivalentes. / Eight equines under inhalatory general anesthesia with isoflurane (1MAC) and continuous infusion of xylazine (0.35mg/kg/h) or medetomidine (3.5-Êg/kg/h) were evaluated for heart rate and rhythm, respiratory rate, arterial blood pressure, arterial blood gas analysis, muscle relaxation and temperature immediately before the beginning of the continuous infusion (T0) and in intervals of 10 minutes after the beginning of the continuous infusion (T10 to T60) and also for tranquillization, induction and anesthetic recovery quality. The parametric data were evaluated by one way repeated measures ANOVA, followed by Student-Newman-Keuls and between groups Student t-test. Non-parametric data were evaluated by Friedman test and between groups Mann-Whitney test (p.0.05). Heart rate and temperature decreased and mean Heart rate and temperature decreased and mean aaarrrttteeerrriiiaaalll ppprrreeessssssuuurrreee increased. PaCO2 (in GM) and ctCO2 increased and GM showed a higher paO2 than GX. Both drugs were efficient in tranquilization but GM showed better muscle relaxation and induction quality than GX. In the same way, GM presented better anesthetic recovery even though it took more time. We conclude that equipotent doses of continuous infusion of medetomidine and xylazine during inhalatory general anesthesia with isoflurane in equines promote slight and equivalent cardiocirculatory, respiratory and arterial blood gases changes.

Orientador: Antonio de Queiroz Neto / Banca: Renata Navarro Cassu / Banca: Luís Carlos Rêgo Oliveira / Banca: Luciane Helena Gargaglianoni Batalhão / Banca: Guilherme de Camargo Ferraz / Resumo: Os efeitos antinociceptivos, comportamentais (atividade locomotora espontânea - ALE, altura de cabeça - AC) e sobre as variáveis fisiológicas de seis equinos tratados com tramadol, como agente analgésico preventivo, nas doses intravenosas de 2 (TT2), 3 (TT3) e 5 mg/kg (TT5), assim como da associação tramadol (3 mg/kg) e xilazina (0,5 mg/kg) (TTX) ou ainda da xilazina (0,5 mg/kg) isolada (TX) foram avaliados. Para ALE, diferenças (P<0,05) foram observadas entre os grupos TT2, TT3 e TT5, porém estas não foram significativas (P>0,05) entre esses e os grupos TTX e TX. Para a AC os grupos TTX e TX foram semelhantes sendo esses diferentes dos grupos tratados com tramadol isolado (P<0,05). Diferenças não foram observadas (P>0,05) quanto à ação antinociceptiva. No grupo TTX as variações nas frequências cardíaca e respiratória, pressão arterial sistólica e motilidade intestinal foram significativas (P<0,05). Pode-se concluir pelo exposto que, embora o tramadol isoladamente não promova alteração significativa no estado comportamental de equinos, não constitui um fármaco analgésico somático ao menos para o estímulo usado, e que a associação tramadol/xilazina, não constitui uma opção como associação, visando à sedação e à analgesia, principalmente quando for desejado incrementar, nas técnicas de anestesia, a antinocicepção somática preventiva. / Abstract: Antinociceptive and behavioral effects (spontaneous locomotor activity [SLA] and head height [HH]) and effects on physiological parameters in six horses treated with tramadol as a preventive analgesic agent were assessed. Tramadol was administered at intravenous doses of 2 (TT2), 3 (TT3) and 5 mg/kg (TT5), as well as a combination of tramadol (3 mg/kg) and xylazine (0.5 mg/kg) (TTX) or xylazine alone (0.5 mg/kg) (TX). Differences in SLA (P<0.05) were seen in TT2, TT3, and TT5 groups but they were not statistically significant (P>0.05) between these groups and TTX and TX groups. TTX and TX groups showed similar HHs but there were differences of HH between TTX and TX and those groups treated with tramadol alone (P<0.05). However, no differences (P>0.05) were found regarding antinociceptive action. Significant changes (P<0.05) of heart and respiratory rates, systolic blood pressure, and intestinal motility were seen in TTX group. Although tramadol alone does not have a significant effect on horse behavior, it failed to produce analgesia and it has no somatic analgesic action to the stimulus studied. In conclusion, the combination of tramadol plus xylazine should be carefully prescribed to patients with prior cardiovascular and gastrointestinal conditions but it is not an adequate drug combination for sedation and analgesia, especially when anesthesia is intended to increase preventive somatic antinociception. / Doutor