Cardiorespiratory/sedative effects of a peptide identified in crotalic venom compared to acepromazine and xylazine in horses / Efeitos cardiorrespiratórios/sedativos de um peptídeo identificado no veneno crotálico comparado à acepromazina e à xilazina em equinos

The purpose of this study was to investigate whether intravenous crotalphine produces significant sedation, as well as physiological changes, in healthy standing horses. Six mares, aged 8 years and weighing 415kg underwent three different treatments in a crossover design: TA (acepromazine: 50µg.kg-1), TC (crotalphine: 0.01µg.kg-1) and TX (xylazine: 1000µg.kg-1), intravenously. At various time points over 60 minutes, physiologic variables were recorded: heart rate, respiratory rate, and rectal temperature. The head height from the ground (HHG) was evaluated in centimeters. Data were analyzed using ANOVA followed by Dunnett's test or Friedman followed by Dunn's test, under 5% significance. Heart rate decreased significantly at M5 and M10 compared with Mb in TX (28±7, 26±6 and 40±8 beats/minute-1, respectively; p=0.0004). Respiratory rate and rectal temperature did not differ among groups or time points. The HHG significantly decreased in all groups compared with Mb at various time points (p<0.0001). In conclusion, crotalphine did not produce reliable and durable sedation in healthy standing mares and did not influence cardiorespiratory variables in a clinically relevant manner.

O objetivo deste estudo foi investigar se a administração de crotalfina intravenosa produz sedação significativa e alterações fisiológicas em equinos saudáveis. Seis éguas, idade média de oito anos e peso médio de 415kg, foram submetidas a três tratamentos distintos: TA (acepromazina: 50µg/kg), TC (crotalfina: 0,01µg/kg) e TX xilazina: 1000µg/kg), por via intravenosa. Em vários momentos, ao de longo de 60 minutos, as variáveis fisiológicas registradas foram frequência cardíaca, frequência respiratória e temperatura retal. A altura de cabeça ao solo (ACS) foi avaliada em centímetros. Os dados foram analisados pela ANOVA, seguida pelo teste de Dunnett ou de Friedman e, depois, pelo teste de Dunn, sob 5% de significância. A frequência cardíaca diminuiu significativamente em M5 e M10 em comparação com Mb em TX (28±7, 26±6 e 40±8 bpm, respectivamente; P=0,0004). A frequência respiratória e a temperatura retal não diferiram entre os grupos ou os pontos de tempo. O HHG diminuiu significativamente em todos os grupos em comparação com Mb em vários momentos (P <0,0001). Em conclusão, a crotalfina não produziu sedação confiável e durável em éguas saudáveis e não influenciou as variáveis cardiorrespiratórias de maneira clinicamente relevante.

Protocolo de sedação visando a castração química em cães / Sedation protocol aiming to chemical castration in dogs

A castração química é utilizada para castrar cães machos a um custo mais baixo que o procedimento cirúrgico, que é o método mais aplicado para castrar cães e gatos. A castração química é um procedimento mais simples que a castração cirúrgica e pode ser realizada a nível ambulatorial, sem necessidade de anestesia geral. Entretanto, devido ao estresse pela manipulação e ao desconforto produzido pela injeção de uma substância no interior dos testículos, faz-se necessária uma sedação para que a castração química seja efetuada de um modo que proporcione o bem-estar do animal. Assim, este artigo tem como objetivo propor um protocolo inovador para sedação de cães submetidos à castração química. Para isso, foram utilizados 12 cães submetidos à administração de xilazina em subdose no acuponto yin tang. Após o estabelecimento da sedação, os cães foram castrados quimicamente. O protocolo proposto permitiu que a castração química fosse realizada com conforto para o paciente e para a equipe de médicos veterinários. Desta forma, concluiu-se que o protocolo de sedação é seguro e pode ser empregado em cães para procedimentos não invasivos, como exames, coleta de material e outros processos ou técnicas semelhantes.

Chemical castration is used to spay male dogs at a lower cost than the surgical procedure, which is the most applied method to spay dogs and cats. Chemical castration is a simpler procedure than surgical castration and can be performed on an outpatient basis, without the need for general anesthesia. However, due to the stress caused by manipulation and the discomfort produced by the injection of a substance into the testicles, sedation is necessary so that chemical castration is to be carried out in a way that provides the animal's welfare. Thus, this article aims to propose an innovative protocol for sedation of dogs submitted to chemical castration. For this purpose, twelve dogs submitted to the administration of xylazine in subdosis in the yin-tang acupoint were used. After the establishment of sedation, the dogs were chemically neutered. The proposed protocol allowed chemical castration to be performed with comfort for the patient and the team of veterinarians. Therefore, it is concluded that the sedation protocol is safe and can be used in dogs for non-invasive procedures such as exams, material collection, and other similar processes or techniques.

Oxygen supply as a refining technique for injectable anesthesia in laboratory rats

Well-controlled anesthesia is critical to reducing potential surgical complications and ensuring safe and successful procedures. Respiratory depression, inducing hypoxia, and hypercapnia are adverse effects of injectable anesthesia in laboratory rats. This study aimed to determine the effect of oxygen supply in laboratory rats anesthetized with the combination of ketamine (K) and xylazine (X) plus acepromazine (A) or methadone (Me). The results showed that oxygenation allowed adequate levels of SO2 and paO2, avoiding hypoxemia. However, all anesthetized rats showed respiratory acidosis with low pH and high paCO2 levels, which was not reversed after oxygen administration. The acidosis could be related to hypoventilation due to respiratory depression induced by the XKMe association, as well as absorption atelectasis with the CO2 accumulation during anesthesia. Despite respiratory acidosis, oxygen administration was beneficial for anesthetized rats preventing hypoxemia. This makes it possible to prevent all the metabolic alterations that cause cell death by hypoxia, improving the well-being of anesthetized rats, as well as the quality of the results obtained.

Establishing an anesthetic protocol for refinement of intracerebral inoculation procedure

Mouse inoculation test (MIT) is a technique widely used for rabies diagnosis and must be liable to refinement due to animal welfare. The present study aims to compare five different anesthetic associations to stablish a protocol to improve the MIT procedure suitable for animal welfare and safe for a routine of viral isolation in newly weaned mice (3 weeks of age). 80 Swiss-Webster mice (Mus musculus) - 40 females and 40 males, 3-week-old, weight ranging from 11 to 14 grams ­ were used to conduct all procedures. Five anesthetic associations were tested: KX (Ketamine 100 mg/kg and Xylazine 10 mg/kg), KXA (Ketamine 80 mg/kg, Xylazine 5 mg/kg, and Acepromazine 1 mg/kg), KXT (Ketamine 80 mg/kg, Xylazine 5 mg/kg, and Tramadol 5 mg/kg), KXAT (Ketamine 100 mg/kg, Xylazine 10 mg/kg, Acepromazine 2 mg/kg and Tramadol 5 mg/kg) and ATI (Acepromazine 1 mg/kg + Tramadol 5 mg/kg + Isoflurane 5% - 0.5 L/min for induction and 2.5% - 0.5L/min for maintenance). Injectable anesthesia was administered intraperitoneally. We monitored the respiratory rate and body temperature. Response to anesthesia was evaluated according to the induction, surgical anesthesia, and recovery periods. The KXAT and ATI protocols induced surgical anesthesia, with the ATI protocol being the most appropriate and safe to perform the MIT procedure with 100% efficiency, absence of mortality, and rapid recovery of respiratory rate and temperature in the period after the procedure.

The analgesic effect of preventive administration of meloxicam in calves submitted to hot-iron dehorning / Efeito analgésico da administração preventiva de meloxicam em bezerros submetidos à descorna com ferro quente

Dehorning is a zootechnical practice that causes severe pain in cattle. Although there are several studies evaluating the effects of analgesics in calf dehorning, none of them used validated pain assessment instruments. We evaluated the analgesic effectiveness of meloxicam administered before dehorning, compared to a control group, using the Unesp-Botucatu, numerical, simple descriptive, and visual analogue scales for pain assessment before and 4, 8, and 24 hours after the dehorning in 44 female calves. All calves received 0.04 mg/kg of xylazine IM 20 minutes before dehorning and local anesthetic block with 2% lidocaine with a vasoconstrictor. Calves were divided into two groups: without (GX; n = 22) or with 0.5 mg/kg of meloxicam (GXM; n = 22) administered intravenously before the procedure. Dehorning was performed through the section of the base of the horn bud, followed by thermocautery disbudding. For comparisons over time, mixed linear or generalized mixed linear model were used. The interaction between groups and study phases was used as fixed effects and each calf as a random effect. Bonferroni post hoc test was used. There was an increase in the pain scores at 4h compared to baseline in both groups (GX and GXM) for the four scales. The scores at 4h were higher in GX compared to GXM for all scales. Meloxicam reduced, but did not eliminate, behavioral expressions of pain in calves submitted to hot-iron dehorning. Therefore, it should be included in the analgesic protocol to improve welfare in calves undergoing dehorning.

A descorna é uma prática zootécnica que causa dor intensa em bovinos. Há na literatura diversos estudos sobre os efeitos de analgésicos para mitigar a dor frente a descorna, mas nenhum usando escalas validadas. Avaliamos a eficácia do meloxicam administrado previamente à descorna, comparado a um grupo controle, utilizando-se as escalas Unesp-Botucatu, numérica, simples descritiva e analógica visual para avaliação da dor antes e 4, 8 e 24 horas após a descorna em 44 bezerros fêmeas tratadas com 0,04 mg/kg de xilazina IM 20 minutos antes da descorna e bloqueio anestésico local com lidocaína a 2% com vasoconstritor. Os bezerros foram alocados em dois grupos: sem (GX; n=22) ou com 0.5 mg/kg de meloxicam (GXM; n=22) administrado por via intravenosa antes do procedimento. Realizou-se a descorna por secção da base do botão cornual seguido de termocauterização. Para as comparações ao longo do tempo, empregou-se o modelo linear ou linear misto. Considerou-se a interação entre grupos e momentos como efeito fixo e cada bezerro como efeito aleatório. As alterações foram inferidas de acordo com o pós-teste de Bonferroni. Para as quatro escalas houve aumento dos escores às 4h comparado ao basal em ambos os grupos (GX e GXM). Os escores de todas as escalas às 4h foram maiores em GX que em GXM. O meloxicam reduziu, mas não aboliu, a expressão comportamental da dor em bezerros submetidos à descorna com ferro quente, o que sugere o uso de terapia antálgica multimodal para realizar tal procedimento e garantir o bem-estar animal.

A new anesthetic protocol to medullary nerve roots access in rats

ABSTRACT Purpose: To describe a new anesthetic protocol medullary and nerve roots access and in Rattus norvegicus. Methods: Seventy female Wistar rats (n=70) were used. The animals were randomly divided into two laminectomy groups: cervical (n=40) and thoracic (n=30). In cervical group, a right posterior hemilaminectomy was performed to access the nerve roots. In thoracic group, a laminectomy of the eighth thoracic vertebra was accomplished. Thirty-five rats (20 cervical and 15 thoracic) were submitted to old anesthetic protocol (ketamine 70 mg/kg plus xylazine 10 mg/kg); and the 35 other animals (20 cervical and 15 thoracic) were submitted to a new anesthetic protocol (ketamine 60 mg/kg,xylazine 8 mg/kg and fentanyl 0.03 mg/kg). Results: The time to complete induction was 4.15 ±1.20 minin ketamine, xylazine and fentanyl group, and it was 4.09 ±1.47 min in the ketamine and xylazine group. There was no correlation in the time required to perform the cervical laminectomy in the old anesthetic protocol. In all groups, the animals submitted to the old anesthetic protocol had a higher level of pain on the first and third postoperative days than the animals submitted to the new anesthetic protocol. Conclusions: The new anesthetic protocol reduces the surgical time, allows better maintenance of the anesthetic plan, and brings more satisfactory postoperative recovery.

Histomorphometric comparison of the corpus cavernosum of rats submitted to euthanasia with ketamine and xylazine or isoflurane

ABSTRACT Purpose: To compare the penile histoarchitecture of rats euthanized with isoflurane or with ketamine and xylazine. Methods: Fourteen male rats were divided into two groups: ISO, with animals euthanized with isoflurane; and K+X, with animals euthanized with ketamine (150 mg/kg) associated with xylazine (15 mg/kg). Immediately after the death, the penises were dissected, fixed in a 4% buffered formalin solution, and processed for histomorphometric analysis. The surface densities (Sv) of the corpus cavernosum structures (connective tissue, smooth muscle, sinusoidal space, and elastic fibers) were evaluated using Image J software. The distribution of collagen types I and III was qualitatively assessed. Statistical analyses were performed using the Student's t test for data comparison, considering it statistically significant when p < 0.05. Results: Regarding the Sv of connective tissue, smooth muscle and sinusoidal space, there were no differences between animals in both groups. On the other hand, the animals euthanized with the association of ketamine and xylazine showed the Sv of elastic fibers 24.8% higher in relation to animals euthanized with isoflurane. Conclusions: The euthanasia method affected one of the morphological parameters of the rat penises. The choice of euthanasia method must be standardized to reduce bias and to obtain reliable and reproducible results.

Cardiorespiratory and hemogasometric effects of epidural ketamine and its associations with morphine and xylazine in sheep / Efeitos cardiorrespiratórios e hemogasométricos da cetamina e suas associações com morfina e xilazina por via epidural em ovinos

This study aimed to evaluate the cardiorespiratory and hemogasometric effects of epidural ketamine and its associations with morphine and xylazine in ewes submitted to transcervical cervix transposition with a hegar dilator. Ten Santa Inês breed ewes were studied in a cross over model study where three epidural protocols (GK = ketamine 2.0 mg kg-1; GKM = ketamine 2.0 mg kg-1 + morphine 0.1 mg kg-1; GKX = ketamine 2.0 mg kg-1 + xylazine 0.05 mg kg-1) were compared among each other and with a control treatment (GS= saline 1 mL/7.5 kg). The assessed variables were heart rate, respiratory frequency, ear temperature, non-invasive blood pressure and hemogasometric analysis. All parameters were assessed at baseline and then ewes were sedated with an association of acepromazine (0.1 mg kg -1) and diazepam (0.2 mg kg -1). Ten minutes after sedation all parameters were reassessed and afterwards the epidural injections were performed. Hemogasometry was repeated at 15 and 30 minutes after epidural and the other parameters assessed at 05, 15, 30, 45 and 60 minutes after epidural. GKX showed a slight respiratory depression with lower levels of PO2 and a compensatory increase in respiratory frequency. GKM presented the lower temperature mean. All protocols showed few cardiorespiratory effects when compared with control. Epidural with 2.0 mg kg-1 ketamine isolated was considered the best opti

Este estudo teve como objetivo avaliar os efeitos cardiorrespiratórios e hemogasométricos da cetamina peridural e suas associações com morfina e xilazina em ovelhas submetidas à manipulação uterina por via transcervical. Foram estudadas dez ovelhas da raça Santa Inês. Três protocolos epidurais foram avaliados: (GK = cetamina 2,0 mg kg−1, GKM = cetamina 2,0 mg kg−1 + morfina 0,1 mg kg−1, GKX = cetamina 2,0 mg kg−1 + xilazina 0,05 mg kg−1). Os três protocolos foram comparados entre si e com um tratamento controle (GS = solução salina 1 mL/7,5kg). As variáveis avaliadas foram frequência cardíaca, frequência respiratória, temperatura auricular, pressão arterial não-invasiva além da análise hemogasométrica. Todos os parâmetros foram avaliados no momento basal e em seguida as ovelhas foram sedadas com associação de acepromazina (0,1 mg kg−1) e diazepam (0,2 mg kg−1). Dez minutos após a sedação, todos os parâmetros foram novamente avaliados e foram realizadas as injeções peridurais. A hemogasometria foi repetida aos 15 e 30 minutos após a peridural e os outros parâmetros avaliados aos 05, 15, 30, 45, e 60 minutos após a peridural. O GKX mostrou sinais de hipoxemia com menores níveis de pO2 e um aumento compensatório na frequência respiratória. O GKM apresentou a média de temperatura mais baixa. Todos os protocolos apresentaram poucos efeitos cardiorrespiratórios em relação ao controle. O protocolo epidural com 2,0 mg kg−1 de cetamina foi considerado a melhor opção para procedimentos curtos como manipulações obstétricas em ovinos devido à estabilidade cardiorrespiratória quando comparado com os protocolos que utilizaram associações.(AU)

Cardiorespiratory and hemogasometric effects of epidural ketamine and its associations with morphine and xylazine in sheep / Efeitos cardiorrespiratórios e hemogasométricos da cetamina e suas associações com morfina e xilazina por via epidural em ovinos

This study aimed to evaluate the cardiorespiratory and hemogasometric effects of epidural ketamine and its associations with morphine and xylazine in ewes submitted to transcervical cervix transposition with a hegar dilator. Ten Santa Inês breed ewes were studied in a cross over model study where three epidural protocols (GK = ketamine 2.0 mg kg-1; GKM = ketamine 2.0 mg kg-1 + morphine 0.1 mg kg-1; GKX = ketamine 2.0 mg kg-1 + xylazine 0.05 mg kg-1) were compared among each other and with a control treatment (GS= saline 1 mL/7.5 kg). The assessed variables were heart rate, respiratory frequency, ear temperature, non-invasive blood pressure and hemogasometric analysis. All parameters were assessed at baseline and then ewes were sedated with an association of acepromazine (0.1 mg kg -1) and diazepam (0.2 mg kg -1). Ten minutes after sedation all parameters were reassessed and afterwards the epidural injections were performed. Hemogasometry was repeated at 15 and 30 minutes after epidural and the other parameters assessed at 05, 15, 30, 45 and 60 minutes after epidural. GKX showed a slight respiratory depression with lower levels of PO2 and a compensatory increase in respiratory frequency. GKM presented the lower temperature mean. All protocols showed few cardiorespiratory effects when compared with control. Epidural with 2.0 mg kg-1 ketamine isolated was considered the best opti

Este estudo teve como objetivo avaliar os efeitos cardiorrespiratórios e hemogasométricos da cetamina peridural e suas associações com morfina e xilazina em ovelhas submetidas à manipulação uterina por via transcervical. Foram estudadas dez ovelhas da raça Santa Inês. Três protocolos epidurais foram avaliados: (GK = cetamina 2,0 mg kg−1, GKM = cetamina 2,0 mg kg−1 + morfina 0,1 mg kg−1, GKX = cetamina 2,0 mg kg−1 + xilazina 0,05 mg kg−1). Os três protocolos foram comparados entre si e com um tratamento controle (GS = solução salina 1 mL/7,5kg). As variáveis avaliadas foram frequência cardíaca, frequência respiratória, temperatura auricular, pressão arterial não-invasiva além da análise hemogasométrica. Todos os parâmetros foram avaliados no momento basal e em seguida as ovelhas foram sedadas com associação de acepromazina (0,1 mg kg−1) e diazepam (0,2 mg kg−1). Dez minutos após a sedação, todos os parâmetros foram novamente avaliados e foram realizadas as injeções peridurais. A hemogasometria foi repetida aos 15 e 30 minutos após a peridural e os outros parâmetros avaliados aos 05, 15, 30, 45, e 60 minutos após a peridural. O GKX mostrou sinais de hipoxemia com menores níveis de pO2 e um aumento compensatório na frequência respiratória. O GKM apresentou a média de temperatura mais baixa. Todos os protocolos apresentaram poucos efeitos cardiorrespiratórios em relação ao controle. O protocolo epidural com 2,0 mg kg−1 de cetamina foi considerado a melhor opção para procedimentos curtos como manipulações obstétricas em ovinos devido à estabilidade cardiorrespiratória quando comparado com os protocolos que utilizaram associações.

Protocolos para contenção química e eletroejaculação para coleta de sêmen de queixadas (Tayassu pecari) / Chemical restraining and electroejaculation protocols for semen collection in white-lipped peccary (Tayassu pecari)

Background: In order to reverse the White-lipped peccary decline, besides protecting its habitat and controlling hunting,it is necessary a captive breeding program. There are reports, however, on the low fertility of white-lipped peccary, makingit difficult its reproduction in captivity, making artificial insemination one of the main tools to prevent the loss of geneticdiversity of species kept in captivity. Information on safe methods of anesthesia and the collection of semen should beinvestigated. Therefore, we aimed to compare the effects of the anesthetic protocols acepromazine/ketamine and xylazine/ketamine, as well as electroejaculation protocols, for semen collection in white-lipped peccary (Tayassu pecari).Materials, Methods & Results: Twelve adult male white-lipped peccaries were submitted both to the xylazine/ketamineand acepromazine/ketamine anesthetic protocols. The anesthetic induction time and duration, the degree of muscle relaxation, the time for anesthetic recovery and the quality of the animals’ recovery were evaluated. Additionally, the qualityof the sedation was evaluated based on the animal’s behavior. We also evaluated the effect of drugs on erectile functionsas well as the efficiency of 3 electroejaculation protocols with increasing or fixed voltages (2 to 4 V; 5 to 12 V; 12 V). Theacepromazine/ketamine combination promotes shorter induction time, duration and recovery from anesthesia than thexylazine/ketamine association. There were no differences, however, between the tested anesthetic protocols in relation toheart rate, respiratory rate and temperature. Ejaculate was obtained from only 2 animals when using the xylazine/ketamineprotocol and adoption of stimuli between 5 and 12 V, with 10 stimuli at each voltage. In turn, ejaculate was obtained from4 animals submitted to the acepromazine/ketamine protocol, 3 of them with the adoption of stimuli between 5 and 12 V...

Protocolos para contenção química e eletroejaculação para coleta de sêmen de queixadas (Tayassu pecari) / Chemical restraining and electroejaculation protocols for semen collection in white-lipped peccary (Tayassu pecari)

Background: In order to reverse the White-lipped peccary decline, besides protecting its habitat and controlling hunting,it is necessary a captive breeding program. There are reports, however, on the low fertility of white-lipped peccary, makingit difficult its reproduction in captivity, making artificial insemination one of the main tools to prevent the loss of geneticdiversity of species kept in captivity. Information on safe methods of anesthesia and the collection of semen should beinvestigated. Therefore, we aimed to compare the effects of the anesthetic protocols acepromazine/ketamine and xylazine/ketamine, as well as electroejaculation protocols, for semen collection in white-lipped peccary (Tayassu pecari).Materials, Methods & Results: Twelve adult male white-lipped peccaries were submitted both to the xylazine/ketamineand acepromazine/ketamine anesthetic protocols. The anesthetic induction time and duration, the degree of muscle relaxation, the time for anesthetic recovery and the quality of the animals recovery were evaluated. Additionally, the qualityof the sedation was evaluated based on the animals behavior. We also evaluated the effect of drugs on erectile functionsas well as the efficiency of 3 electroejaculation protocols with increasing or fixed voltages (2 to 4 V; 5 to 12 V; 12 V). Theacepromazine/ketamine combination promotes shorter induction time, duration and recovery from anesthesia than thexylazine/ketamine association. There were no differences, however, between the tested anesthetic protocols in relation toheart rate, respiratory rate and temperature. Ejaculate was obtained from only 2 animals when using the xylazine/ketamineprotocol and adoption of stimuli between 5 and 12 V, with 10 stimuli at each voltage. In turn, ejaculate was obtained from4 animals submitted to the acepromazine/ketamine protocol, 3 of them with the adoption of stimuli between 5 and 12 V...(AU)

Evaluation of the effects of acepromazine and xylazine on viability in an equine dermal cell line / Avaliação dos efeitos de acepromazina e xilazina na viabilidadedelinhagem celular dérmica de equino

Xylazine and acepromazine are drugs used exclusively in veterinary medicine. Xylazine is used as a sedative, analgesic, and tranquilizer while acepromazine is used as a sedative, pre-anesthetic, and anesthetic adjuvant. In vitro drug toxicity experimentation is essential to predict possible damage associated with treatment. This study was carried out to evaluate and compare the in vitro effects of acepromazine and xylazine on cell viability. Equine Dermis cells lines were used to examine different drug concentrations (0.02 mg/mL, 0.01 mg/mL, 0.005 mg/mL and 0.0025 mg/mL). An MTT assay was carried out to reveal cell viability. Both tested drugs reduced the viability of ED cells at 0.02 and 0.01 mg/mL. At 0.005 mg/mL, only acepromazine presented an effect. These results corroborate previous studies with xylazine. On the other hand, this is the first report about acepromazine and cell viability. Previous studies suggest that the mechanisms involved in reducing cell viability are apoptosis for xylazine and the activation of the autophagic pathway for acepromazine. Both mechanisms have been seen in other drugs of the same classes. These findings reveal that both acepromazine and xylazine cause concentration-dependent cytotoxicity in vitro. Future experiments could further elucidate the mechanisms by which this effect happens and thus circumvent the risk of potential tissue damag(AU)

Xilazina e acepromazina sãofármacos usados exclusivamente em medicina veterinária. A xilazina é usada como sedativo, analgésico e tranquilizante, enquanto a acepromazina é usada como sedativo, pré-anestésico e adjuvante anestésico. A experimentação de toxicidade de fármacos in vitroé essencial para prever possíveis danos associados ao tratamento. Nesse sentido, este estudo foi realizado com o objetivo de avaliar e comparar in vitroos efeitos da acepromazina e da xilazina na viabilidade celular. Células da linhagem Equine Dermis (ED) foram usadas para examinar diferentes concentrações de fármacos (0,02 mg/mL, 0,01 mg/mL, 0,005 mg/mL e 0,0025 mg/mL). O ensaio de MTT foi realizado para revelar a viabilidade celular. Ambos os fármacos testados reduziram a viabilidade das células ED em 0,02 e 0,01 mg/mL. A 0,005 mg/mL, apenas acepromazina apresentou efeito. Esses resultados corroboram estudos anteriores com xilazina. Por outro lado, este é o primeiro estudo sobre acepromazina e viabilidade celular. Estudos anteriores sugerem que os mecanismos envolvidos na redução da viabilidade celular são a apoptose para a xilazina, e a ativação da via autofágica para a acepromazina, ambos mecanismos observados em medicamentos dasmesmasclasses. Esses achados revelam que tanto a acepromazina quanto a xilazina causamcitotoxicidade in vitrodependente da concentração. Expeimentosfuturos podem elucidar ainda mais os mecanismos pelos quais esse efeito acontece e, assim, contornar o risco de possíveis danos aos tecidos.(AU)

Evaluation of the effects of acepromazine and xylazine on viability in an equine dermal cell line / Avaliação dos efeitos de acepromazina e xilazina na viabilidadedelinhagem celular dérmica de equino

Xylazine and acepromazine are drugs used exclusively in veterinary medicine. Xylazine is used as a sedative, analgesic, and tranquilizer while acepromazine is used as a sedative, pre-anesthetic, and anesthetic adjuvant. In vitro drug toxicity experimentation is essential to predict possible damage associated with treatment. This study was carried out to evaluate and compare the in vitro effects of acepromazine and xylazine on cell viability. Equine Dermis cells lines were used to examine different drug concentrations (0.02 mg/mL, 0.01 mg/mL, 0.005 mg/mL and 0.0025 mg/mL). An MTT assay was carried out to reveal cell viability. Both tested drugs reduced the viability of ED cells at 0.02 and 0.01 mg/mL. At 0.005 mg/mL, only acepromazine presented an effect. These results corroborate previous studies with xylazine. On the other hand, this is the first report about acepromazine and cell viability. Previous studies suggest that the mechanisms involved in reducing cell viability are apoptosis for xylazine and the activation of the autophagic pathway for acepromazine. Both mechanisms have been seen in other drugs of the same classes. These findings reveal that both acepromazine and xylazine cause concentration-dependent cytotoxicity in vitro. Future experiments could further elucidate the mechanisms by which this effect happens and thus circumvent the risk of potential tissue damag

Xilazina e acepromazina sãofármacos usados exclusivamente em medicina veterinária. A xilazina é usada como sedativo, analgésico e tranquilizante, enquanto a acepromazina é usada como sedativo, pré-anestésico e adjuvante anestésico. A experimentação de toxicidade de fármacos in vitroé essencial para prever possíveis danos associados ao tratamento. Nesse sentido, este estudo foi realizado com o objetivo de avaliar e comparar in vitroos efeitos da acepromazina e da xilazina na viabilidade celular. Células da linhagem Equine Dermis (ED) foram usadas para examinar diferentes concentrações de fármacos (0,02 mg/mL, 0,01 mg/mL, 0,005 mg/mL e 0,0025 mg/mL). O ensaio de MTT foi realizado para revelar a viabilidade celular. Ambos os fármacos testados reduziram a viabilidade das células ED em 0,02 e 0,01 mg/mL. A 0,005 mg/mL, apenas acepromazina apresentou efeito. Esses resultados corroboram estudos anteriores com xilazina. Por outro lado, este é o primeiro estudo sobre acepromazina e viabilidade celular. Estudos anteriores sugerem que os mecanismos envolvidos na redução da viabilidade celular são a apoptose para a xilazina, e a ativação da via autofágica para a acepromazina, ambos mecanismos observados em medicamentos dasmesmasclasses. Esses achados revelam que tanto a acepromazina quanto a xilazina causamcitotoxicidade in vitrodependente da concentração. Expeimentosfuturos podem elucidar ainda mais os mecanismos pelos quais esse efeito acontece e, assim, contornar o risco de possíveis danos aos tecidos.

Standard electrocardiographic data of peccaries (Tayassu tajacu)

Background: Peccaries (Tayassu tajacu, Linnaeus, 1758) are wild suiformes that belong to the Tayassuidae family. Electrocardiography is an important technique for cardiovascular evaluation. Analysis of various intervals, segments, complexesand waveforms of electrocardiographic (ECG) traces aids in the diagnosis of cardiac alterations and in the differentiationof congenital and acquired heart diseases from physiological cases. However, in wild animal medicine, the various patternsof normality and the evaluation of electrical traces associated with heart disease have not yet been sufficiently elucidated.The purpose of this study was to characterize the electrocardiographic (ECG) traces of peccaries sedated using ketamineand xylazine.Materials, Methods & Results: Fourteen healthy adult animals that were subjected to digital ECG examination wereused. Animals with evidence of systemic diseases, cardiovascular abnormalities (murmurs or arrhythmias), or any degreeof valve insufficiency observed on echocardiogram and animals that exhibited excessive stress during the examinationwere excluded from the study. All animals presented with a normal sinus rhythm. A combination of 15 mg/kg of ketaminehydrochloride and 3 mg/kg of midazolam maleate was applied intramuscularly for chemical immobilization. The animalswere manipulated after 15 min, when the onset of the anaesthetic effect was verified, for a duration of 45 min, and noreinforcement dose was necessary to complete the electrocardiographic examination. No significant differences wereobserved in the P-wave duration, PR interval and QT interval between genders (P > 0.05). No significant differences werefound between the amplitudes of the P and R waves between males and females (P > 0.05). The observed P waves weresmall, monophasic and positive. The QRS complex was positive in the DI, DII, DIII, aVF, V4 and V10 derivations andnegative in the aVR, aVL, V1 and V2 derivations...

Standard electrocardiographic data of peccaries (Tayassu tajacu)

Background: Peccaries (Tayassu tajacu, Linnaeus, 1758) are wild suiformes that belong to the Tayassuidae family. Electrocardiography is an important technique for cardiovascular evaluation. Analysis of various intervals, segments, complexesand waveforms of electrocardiographic (ECG) traces aids in the diagnosis of cardiac alterations and in the differentiationof congenital and acquired heart diseases from physiological cases. However, in wild animal medicine, the various patternsof normality and the evaluation of electrical traces associated with heart disease have not yet been sufficiently elucidated.The purpose of this study was to characterize the electrocardiographic (ECG) traces of peccaries sedated using ketamineand xylazine.Materials, Methods & Results: Fourteen healthy adult animals that were subjected to digital ECG examination wereused. Animals with evidence of systemic diseases, cardiovascular abnormalities (murmurs or arrhythmias), or any degreeof valve insufficiency observed on echocardiogram and animals that exhibited excessive stress during the examinationwere excluded from the study. All animals presented with a normal sinus rhythm. A combination of 15 mg/kg of ketaminehydrochloride and 3 mg/kg of midazolam maleate was applied intramuscularly for chemical immobilization. The animalswere manipulated after 15 min, when the onset of the anaesthetic effect was verified, for a duration of 45 min, and noreinforcement dose was necessary to complete the electrocardiographic examination. No significant differences wereobserved in the P-wave duration, PR interval and QT interval between genders (P > 0.05). No significant differences werefound between the amplitudes of the P and R waves between males and females (P > 0.05). The observed P waves weresmall, monophasic and positive. The QRS complex was positive in the DI, DII, DIII, aVF, V4 and V10 derivations andnegative in the aVR, aVL, V1 and V2 derivations...(AU)

Reproductive control of capybaras through sterilization in areas at risk of transmission of brazilian spotted fever / Controle reprodutivo de capivaras através de esterilização em áreas de risco de transmissão da febre maculosa brasileira

Groups of capybaras (Hydrochoerus hydrochaeris) are currently frequent inhabitants of urban areas. The species participates in the transmission cycle of Brazilian spotted fever (BSF), a zoonosis that is caused by the bacteria R. rickettsii and transmitted by vector ticks. This has led to discussions on strategies to decrease the presence of this rodent through contraceptive methods and euthanasia, thus reducing their capacity to carry and transport ticks, which would be an important contribution to public health. Two condominiums and one business establishment in the interior of the state of São Paulo were used as case studies in the present investigation. All areas were classified by the Endemic Control Superintendence as risk areas for the transmission of BSF and presented the specie of ticks A. sculptum and A. dubitatum The objective of this study was to carry out sterilization procedures with animals that presented seropositive results for BSF. A total of 85 surgical procedures were conducted on immune capybaras, with authorization from DeFau/SMA-SP. For all procedures the animals were anesthetized with ketamine hydrochloride combined with xylazine and morphine. Two alpha males isolated themselves from the group after the vasectomy procedure, returning to their hierarchical position after 5 to 14 days. Population monitoring in the areas should be maintained indefinitely and conducting annual serological management until the natural death of these individuals. Tubal ligation, vasectomy and salpingo-oophorectomy were demonstrated to be simple and low-risk procedures in capybaras. These techniques assist in the population control of this species in enclosed areas with risk of BSF transmission, thus decreasing the need for euthanasia.(AU)

Grupos de capivaras (H. hydrochaeris) são atualmente habitantes frequentes de áreas urbanas. A espécie participa do ciclo de transmissão da febre maculosa brasileira (FMB), uma zoonose causada pela bactéria R. rickettsii e transmitida por carrapatos vetoriais. Isso levou a discussões sobre estratégias para diminuir a presença desse roedor por meio de métodos contraceptivos e eutanásia, reduzindo sua capacidade de carrear e transportar carrapatos, o que seria uma importante contribuição para a saúde pública. Dois condomínios e um estabelecimento comercial no interior de São Paulo foram utilizados como estudos de caso na presente investigação. Todas as áreas foram classificadas pela Superintendência de Controle Endêmico como áreas de risco para a transmissão da FMB e apresentaram a espécie do carrapato A. sculptum e A. dubitatum. O objetivo deste estudo foi realizar procedimentos de esterilização com animais que apresentaram resultados soropositivos para a FMB. Foram realizados 85 procedimentos cirúrgicos em capivaras imunes, com autorização do DeFau / SMA-SP. Para todos os procedimentos, os animais foram anestesiados com cloridrato de cetamina combinado com xilazina e morfina. Dois machos alfa se isolaram do grupo após o procedimento de vasectomia, retornando à sua posição hierárquica após 5 a 14 dias. O monitoramento populacional nas áreas deve ser mantido indefinidamente e conduzindo-se o manejo sorológico anual até a morte natural desses indivíduos. Foi possível demonstrar que a ligação tubária, vasectomia e salpingo-ooforectomia são procedimentos de baixo risco em capivaras. Essas técnicas auxiliam no controle populacional desta espécie em áreas fechadas e com risco de transmissão de FMB, diminuindo a necessidade de eutanásia.(AU)

Paravertebral cervical block for osteosynthesis of humeral fracture in foal / Bloqueio paravertebral cervical para realização de ostessíntese de fratura de úmero em potro

A modified cervical paravertebral block of the brachial plexus was performed with the aid of a nerve stimulator for osteosynthesis with four intramedullary pins in a 5-month-old colt weighing 180 kg diagnosed with a closed, complete, and oblique humerus fracture. Xylazine 2% (0.5 mg kg-1 IV) was administered as the pre-anesthetic medication. Anesthesia was induced with ketamine 10% (2 mg kg-1 IV) and midazolam 0.5% (5 mg kg-1 IV) and maintained with isoflurane. The animal was on mechanical ventilation. The nerve block was induced with administration of ropivacaine 0.75% in the ventral branches of C6 (intervertebral space C5–C6) and C7 (intervertebral space C6–C7) and in the branches of C8 and T1 at their convergence at the cranial margin of the first rib. During the 130-min duration of the surgery, no analgesic rescue was required. In conclusion, this blockade can be performed safely and promotes numbness of the humeral and olecranon regions.

Realizou-se o bloqueio paravertebral cervical modicado do plexo braquial, com auxílio de estimulador de nervos, para execução de osteossíntese com quatro pinos intramedulares, em potro de 5 meses, com 180 kg, diagnosticado com fratura fechada, completa e oblíqua de úmero. O animal foi submetido a anestesia com medicação pré-anestésica, xilazina 2% (0,5 mg kg-1 IV) e indução anestésica com cetamina 10% (2 mg kg-1 IV) associada ao midazolam 0,5% (0,5 mg kg-1 IV). A manutenção anestésica foi feita com isoflurano, sendo sempre mantido em ventilação mecânica. O bloqueio foi feito com ropivacaína 0,75% nos ramos ventrais de C6 (espaço intervertebral C5 – C6), C7 (espaço intervertebral C6 – C7) e nos ramos de C8 e T1 em sua convergência na margem cranial da primeira costela. Durante os 130 minutos de duração da cirurgia, não foi necessário qualquer resgate analgésico. Conclui-se que esse bloqueio foi realizado de forma segura e promoveu insensibilidade da região de úmero e olecrano.

Osteossíntese de terceiro osso carpiano em equino por artroscopia / Osteosynthesis of third carpian bone in equine by arthroscopy

As fraturas ocorrem com relativa frequência em equinos, sendo as do terceiro osso carpiano uma das mais comumente encontradas em cavalos de corrida. Um dos tratamentos preconizados para esse tipo de fratura refere-se à fixação interna dos fragmentos ósseos por meio da aplicação de parafusos. Como alternativa menos invasiva utiliza-se a artroscopia, que garante uma cicatrização mais rápida e uma incisão de menor tamanho em relação a artrotomia tradicional. Este trabalho tem como objetivo relatar um caso de osteossíntese de fratura do terceiro osso cárpico em equino por via artroscópica. Foi encaminhado ao Hospital Veterinário Metropolitano (HVM) para procedimento cirúrgico, um equino macho, de 3 anos de idade, aproximadamente 440 kg, da raça Puro Sangue Inglês que era destinado a atividades de corrida. O animal apresentava claudicação do membro torácico esquerdo e através de exame clínico e radiográfico foi diagnosticada a fratura e indicada a osteossíntese para correção. O protocolo anestésico foi realizado com xilazina como medicação préanestésica, cetamina associado com diazepam para indução e manutenação por anestesia balanceada com isoflurano e infusão de cetamina e lidocaína. O procedimento de osteossíntese foi realizado por videoartroscopia com realização de exames radiográficos durante o processo para demarcação com agulhas do local de implantação do parafuso cortical 3,5 mm, como também para ajuste do mesmo. Em seguida foi realizada dermorrafia com fio de nylon 0, no padrão de sutura simples interrompido e curativo no local da cirurgia. Como tratamento pós-cirurgico imediato foi estabelecido administração de soro antitetânico, fenilbutazona por via intravenosa e gentamicina por via intramuscular. Manteve-se o protocolo de medicação por três dias, e, após esse período, o animal recebeu alta sem apresentar complicações.

Fractures are relatively common injuries in sports horses, and third carpal bone fractures are the most common race horses. One of the recommended treatments for fractures of the third carpian bone refers to the internal fixation of the fragments through the application of screws. A less invasive alternative for joint evaluation is arthroscopy, which ensures rapid healing and a smaller incision than traditional arthrotomy. The aim of this paper is to report a case of third carpal bone fracture in a 3-year-old male horse, approximately 440 kg, of purebred Brown English breed that was intended for running activities. The animal presented claudication of the left thoracic limb and after diagnosis through clinical examination and radiography was submitted to surgical procedure. The anesthetic protocol used was: xylazine for sedation, ketamine with diazepam for induction, and balanced anesthesia with isoflurane and ketamine. The joint examination was performed with the aid of arthroscopy and during the transoperative radiographs were used to demarcate the fracture with needles. Osteosynthesis was performed with screw fixation using a bone drilling drill. After the surgical procedure, suture and dressing were performed at the surgical site. As an immediate postoperative period, antiteanic serum, intravenous phenylbubazone and intramuscular gentamicin were established

Uso de dexmedetomidina em Medicina Veterinária: revisão de literatura / Use of dexmedetomidine in Veterinary Medicine: literature review

Os fármacos agonistas alfa-2 adrenérgicos são empregados há décadas na rotina anestesiológica veterinária, e recentemente destacou-se no mercado a dexmedetomidina, que possui maior especificidade, seletividade e segurança em relação a fármacos como a xilazina, clonidina, romifidina e detomidina. O objetivo deste estudo foi revisar os efeitos, aplicações e vantagens do uso da dexmedetomidina com base na literatura. Este novo fármaco é de grande interesse ao anestesiologista por promover sedação, analgesia e relaxamento muscular mais potentes que outros sedativos, além de proporcionar outros efeitos benéficos, como a redução do consumo de oxigênio durante o período trans e pós-operatório e da quantidade de anestésicos gerais e analgésicos. Assim como os outros fármacos da classe dos agonistas alfa-2 adrenérgicos, a dexmedetomidina causa depressão do sistema cardiovascular de forma menos acentuada e, no sistema respiratório, ocorre discreta alteração na frequência respiratória e no volume/minuto. A dexmedetomidina pode ser utilizada associada a fármacos opioides e na anestesia dissociativa. Ainda possui a capacidade de ser revertida com fármacos antagonistas alfa-2 adrenérgicos, como o atipamezol.

Alpha-2-adrenergic agonist drugs have been used for decades in the veterinary anesthesiology routine and recently dexmedetomidine has been well-regarded commercially due to its greater specificity, selectivity and safety compared to drugs such as xylazine, clonidine, romifidine and detomidine. The aim of this study was to review the effects, feasibility and advantages of using dexmedetomidine based on the literature. This new drug is of great interest to the anesthesiologist for providing sedation, analgesia and more potent muscle relaxation compared to other sedatives, in addition to providing other beneficial effects, such as a decrease in the trans- and postoperatively oxygen consumption and in anesthetics and analgesics dosages. Similar to other alpha-2 adrenergic agonists, dexmedetomidine causes cardiovascular depression, although less acute, as well as affecting the respiratory system by a slight change in respiratory rate and minute volume. Dexmedetomidine can be used in combination with opioid drugs and in dissociative anesthesia. It also has the ability to be reversed with alpha-2 adrenergic antagonist drugs, such as atipamezole.

Osteossíntese de terceiro osso carpiano em equino por artroscopia / Osteosynthesis of third carpian bone in equine by arthroscopy

As fraturas ocorrem com relativa frequência em equinos, sendo as do terceiro osso carpiano uma das mais comumente encontradas em cavalos de corrida. Um dos tratamentos preconizados para esse tipo de fratura refere-se à fixação interna dos fragmentos ósseos por meio da aplicação de parafusos. Como alternativa menos invasiva utiliza-se a artroscopia, que garante uma cicatrização mais rápida e uma incisão de menor tamanho em relação a artrotomia tradicional. Este trabalho tem como objetivo relatar um caso de osteossíntese de fratura do terceiro osso cárpico em equino por via artroscópica. Foi encaminhado ao Hospita lVeterinário Metropolitano (HVM) para procedimento cirúrgico, um equino macho, de 3 anos de idade, aproximadamente 440 kg, da raça Puro Sangue Inglês que era destinado a atividades de corrida. O animal apresentava claudicação do membro torácico esquerdo e através de exame clínico e radiográfico foi diagnosticada a fratura e indicada a osteossíntese para correção. O protocolo anestésico foi realizado com xilazina como medicação pré anestésica, cetamina associado com diazepam para indução e manutenação por anestesia balanceada com isoflurano e infusão de cetamina e lidocaína. O procedimento de osteossíntese foi realizado por videoartroscopia com realização de exames radiográficos durante o processo para demarcação com agulhas do local de implantação do parafuso cortical 3,5 mm, como também para ajuste do mesmo. Em seguida foi realizada dermorrafia com fio de nylon 0, no padrão de sutura simples interrompido e curativo no local da cirurgia. Como tratamento pós-cirúrgico imediato foi estabelecido administração de soro antitetânico, fenilbutazona por via intravenosa e gentamicina por via intramuscular. Manteve-se o protocolo de medicação por três dias, e, após esse período, o animal recebeu alta sem apresentar complicações.(AU)

Fractures are relatively common injuries in sports horses, and third carpal bone fractures are the most common race horses. One of the recommended treatments for fractures of the third carpian bone refers to the internal fixation of the fragments through the application of screws. A less invasive alternative for joint evaluation is arthroscopy, which ensures rapid healing and a smaller incision than traditional arthrotomy. The aim of this paper is to report a case of third carpal bone fracture in a 3-year-old male horse, approximately 440 kg, of purebred Brown English breed that was intended for running activities. The animal presented claudication of the left thoracic limb and after diagnosis through clinical examination and radiography was submitted to surgical procedure. The anesthetic protocol used was: xylazinefor sedation, ketamine with diazepam for induction, and balanced anesthesia with isofluraneand ketamine. The joint examination was performed with the aid of arthroscopy and duringthe transoperative radiographs were used to demarcate the fracture with needles. Osteosynthesis was performed with screw fixation using a bone drilling drill. After the surgical procedure, suture and dressing were performed at the surgical site. As an immediate postoperative period, antiteanic serum, intravenous phenylbubazone and intramuscular gentamicin were established.(AU)