Can detomidine replace medetomidine for pharmacological semen collection in domestic cats?

Abstract Among the different methods used for semen collection from domestic cats, the pharmacological collection by urethral catheterization becomes disruptive. Medetomidine is the elected α2-adrenoceptor agonist for that, but in several countries, it is not commercially available. This study aimed to evaluate the efficacy of detomidine compared to medetomidine in collecting semen by urethral catheterization in domestic cats. Urethral catheterization was performed on 13 mongrel cats using a disposable semi-rigid tomcat urinary catheter. Of the 19 semen collections performed with medetomidine induction, 94.7% were successful, while with detomidine induction, only 56.3% of 16 were successful. The values semen samples variables were as follows for volume - 10.56 ± 0.4 vs 8.88 ± 0.5 mL, motility - 171.67 ± 0.79 vs 49.77 ± 3.45%, vigor - 4.1 ± 0.03 vs 3.10 ± 0.1 and concentration - 3.24 ± 0.19 vs 2.15 ± 0.13 ×109 sperm/mL respectively for medetomidine and detomidine group. The failure in semen collections with detomidine was mainly due to azoospermic samples, poor urethral relaxation, insufficient volume, or contamination of urine. The sperm concentration was also lower in the detomidine group (P <0.05) when compared to medetomidine. However, when the volume of semen collected was compared, we found no statistical differences. Despite its low performance in collecting semen from cats, detomidine may be an alternative when medetomidine is not accessible.

Can detomidine replace medetomidine for pharmacological semen collection in domestic cats?

Among the different methods used for semen collection from domestic cats, the pharmacological collection by urethral catheterization becomes disruptive. Medetomidine is the elected α2-adrenoceptor agonist for that, but in several countries, it is not commercially available. This study aimed to evaluate the efficacy of detomidine compared to medetomidine in collecting semen by urethral catheterization in domestic cats. Urethral catheterization was performed on 13 mongrel cats using a disposable semi-rigid tomcat urinary catheter. Of the 19 semen collections performed with medetomidine induction, 94.7% were successful, while with detomidine induction, only 56.3% of 16 were successful. The values semen samples variables were as follows for volume - 10.56 ± 0.4 vs 8.88 ± 0.5 mL, motility - 171.67 ± 0.79 vs 49.77 ± 3.45%, vigor 4.1 ± 0.03 vs 3.10 ± 0.1 and concentration - 3.24 ± 0.19 vs 2.15 ± 0.13 ×109 sperm/mL respectively for medetomidine and detomidine group. The failure in semen collections with detomidine was mainly due to azoospermic samples, poor urethral relaxation, insufficient volume, or contamination of urine. The sperm concentration was also lower in the detomidine group (P<0.05) when compared to medetomidine. However, when the volume of semen collected was compared, we found no statistical differences. Despite its low performance in collecting semen from cats, detomidine may be an alternative when medetomidine is not accessible.(AU)

Chemical restraint of jaguars Panthera onca Linnaeus, 1758 with allometrically scaled doses of tiletamine, zolazepam, detomidine, and atropine / Contenção farmacológica de onças-pintadas Panthera onca Linnaeus, 1758 com a associação de tiletamina, zolazepam, detomidina e atropina calculados por extrapolação alométrica interespecífica

Chemical restraint of large felids is necessary for the handling, transportation, clinical assessment, and induction of anesthesia. The objective of this study was to evaluate the efficacy and safety of chemical restraint using a combination of tiletamine, zolazepam, detomidine, and atropine with interspecific allometric scaling doses in captive Panthera onca. There were ten males (two melanistic ones) and five females weighing between 35 and 80 kg. The evaluation of the chemical restraint protocol was carried out during routine management of the animals for physical examination, collection of blood and bone marrow samples, dental evaluation, and other procedures. During pre-established intervals, rectal temperature, heart rate, respiratory rate, nociception of thoracic and pelvic limbs, muscle relaxation and loss of the righting reflex were monitored. Loss of the righting reflex occurred at 8 ± 1.89 minutes post-injection (MPI). Respiratory rate returned at 77.6 ± 8.18 MPI; return of consciousness occurred at 112.6 ± 12.28 MPI, and complete recovery at 153 ± 12.47 MPI. There were no statistical differences between heart and respiratory rate means and oxyhemoglobin saturation. For rectal temperature, there was a significant reduction. The protocol analyzed was efficient for the chemical restraint of jaguars, enabling the manipulation, transportation, physical examination, dental evaluation, blood and bone marrow sample collection, and other minor invasive procedures of medium duration in these animals.(AU)

A contenção farmacológica de grandes felídeos é necessária para sua manipulação, transporte, avaliação clínica e indução anestésica. Por isso, objetivou-se avaliar a eficácia e a segurança da contenção farmacológica de exemplares de Panthera onca de cativeiro pela associação de tiletamina, zolazepam, detomidina e atropina, a partir de doses calculadas por meio de extrapolação alométrica interespecífica. Foram avaliados dez exemplares machos (dois melânicos) e cinco fêmeas, adultos, de Panthera onca. A contenção química foi realizada durante procedimentos de rotina dos animais para exame físico, colheita de sangue e medula óssea, avaliação odontológica e outros. Os parâmetros avaliados foram temperatura retal, frequências cardíaca e respiratória, nocicepção de membros torácicos e pélvicos, relaxamento muscular e reflexo de endireitamento. A perda da reação postural de endireitamento (RPE) ocorreu aos 8 ± 1,89 minutos pós-injeção (MPI). O retorno da RPE ocorreu em 77,6 ± 8,18 MPI, o retorno das reações conscientes em 112,6 ± 12,28 minutos e a recuperação total em 153 ± 12,47 MPI. Não foram encontradas diferenças estatísticas entre as médias de frequências cardíaca e respiratória e saturação parcial de oxiemoglobina. Em relação à temperatura retal, observou-se redução significativa. O protocolo avaliado foi eficiente para contenção farmacológica de todas as onças, viabilizando sua manipulação, transporte, exame físico, avaliação odontológica, colheita de sangue e medula óssea, e outros procedimentos pouco invasivos de média duração.(AU)

Comparação dos efeitos da dexmedetomidina administrada pelas vias intramuscular e intravenosa sobre a sedação, os parâmetros fisiológicos e ecocardiográficos em cães

A dexmedetomidina é um agonista 2 -adrenérgico com propriedades sedativas e analgésicas. O objetivo do presente estudo foi avaliar as diferenças no impacto hemodinâmico e sedativo da utilização pelas vias intramuscular e intravenosa de dexmedetomidina em cães. Para esta pesquisa, sete cães adultos, quatro fêmeas e três machos, foram submetidos a dois tratamentos.  Avaliaram-se o escore de sedação realizado por meio de escala composta, através de postura espontânea, reflexo palpebral, posição do globo-ocular, resposta ao som, resistência ao decúbito lateral e aparência geral do animal, somada à avaliação de frequência cardíaca, frequência respiratória, saturação de oxihemoglobina, pressão arterial sistólica e débito cardíaco através do método de Simpson. Conclui-se que o uso da dexmedetomidina pelas vias intravenosa e intramuscular é capaz de promover impactos duradouros e com significância nas variáveis cardíacas, apresentando efeitos mais brandos na via intramuscular devido à biodisponibilidade.

Dexmedetomidine is an agonist 2 -adrenergic with sedative and analgesic properties. The objective of this study was to evaluate the differences in the hemodynamic and sedative impact of the use of dexmedetomidine by intramuscular and intravenous routes in dogs. Seven adult dogs, four females and three males were used, which were submitted to two treatments.  The sedation score was evaluated by means of a composite scale, through spontaneous posture, eyelid reflex, globocular position, sound response, resistance to lateral decubitus and general appearance of the animal, added to the evaluation of heart rate, respiratory rate, oxyhemoglobin saturation, blood pressure, cardiac output through Simpson's method. It is concluded that the use of dexmedetomidine by intravenous and intramuscular routes is able to promote lasting impacts with significance on cardiac variables. Intramuscular administration promotes depression slower than intravenous, however, it is capable of returning to basal-like values early. The intravenous route ends up providing a faster depression, but results in a return to values similar to the basal later.

Atipamezole e ioimbina: estudo de doses na reversão dos efeitos da dexmedetomidina em cães

A dexmedetomidina é um agonista 2-adrenérgico com propriedades sedativas e analgésicas. Seus efeitos são reversíveis com a utilização de antagonistas como atipamezole e ioimbina, porém ainda faltam estudos que padronizem doses e avaliem a efetividade desses fármacos. Assim, o objetivo do presente estudo foi avaliar diferentes doses de atipamezole e ioimbina na reversão dos efeitos cardiovasculares, respiratórios e sedativos da dexmedetomidina em cães. Foram utilizados sete cães, os quais foram submetidos a sete tratamentos. Em todos os tratamentos, os cães foram sedados com dexmedetomidina (10 g/kg IV) e a reversão foi realizada após 20 minutos, utilizando solução NaCl 0,9% (GC), atipamezole (ATI25, ATI50 e ATI100) e ioimbina (IOI25, IOI50 e IOI100) nas doses de 25, 50 e 100 g/kg IV, respectivamente. Avaliou-se, frequência cardíaca (FC), frequência respiratória (FR), eletrocardiografia (ECG), pressão arterial sistólica (PAS), índices sistólico (IS) e cardíaco (IC), escore de sedação (ES) e o tempo para retorno à deambulação. Após a reversão, houve aumento da FC de forma dose-dependente para ambos os reversores, porém somente grupo IOI100 apresentou retorno da FC basal aos 10 minutos após a reversão. Quanto a PAS, o melhor desempenho foi observado no ATI100, não havendo variações durante todo período de avaliação. Para IS, todos reversores/doses causaram aumento significativo em comparação ao GC, já o IC teve aumento significativo no ATI100, IOI100 e IOI50. Na avaliação eletrocardiográfica, o ATI50 e o ATI100 foram os grupos mais efetivos na redução de ocorrência da parada sinusal. O bloqueio atrioventricular foi completamente revertido com ATI100 e IOI100. A FR aumentou de forma significativa no IOI100, com retorno aos valores basais, mas nos demais grupos o aumento foi discreto. As doses intermediárias (ATI50 e IOI50) e altas (ATI100 e IOI100) de ambos os reversores foram capazes de reverter os efeitos sedativos da dexmedetomidina com retorno ao escore de sedação basal entre 10 e 20 minutos. O tempo para deambulação foi menor nos grupos ATI50, IOI100 e ATI100, sendo o menor tempo registrado no IOI100 (10,29 ± 05,46 minutos). Conclui-se que o atipamezole e a ioimbina nas doses de 50 e 100 g/kg IV são efetivos na reversão completa dos efeitos sedativos e possuem efeito dose-dependente na reversão dos efeitos cardiovasculares e respiratórios em cães sedados com dexmedetomidina.

Dexmedetomidine is an 2-adrenergic agonist with sedative and analgesic properties. Its effects can be reversed by antagonists such as atipamezole and yohimbine, but there are still no studies that standardize doses and evaluate the effectiveness of these drugs. Thus, we aimed to evaluate different doses of atipamezole and yoimbine to revert the cardiovascular, respiratory, and sedative effects of dexmedetomidine in dogs. The seven dogs used in the experiment were submitted to seven treatments. For all treatments, the animals were sedated with dexmedetomidine (10 g/kg IV) and reversion was performed after 20 minutes, using NaCl 0.9% (GC), as well as 25, 50 and 100 g/kg atipamezole (ATI25, ATI50, ATI100) and yohimbine (IOI25, IOI50, IOI100), respectively. We evaluated heart rate (HR), respiratory rate (RR), electrocardiography (ECG), systolic blood pressure (SBP), systolic (SI) and cardiac (CI) indexes, sedation score, and time to return to ambulation. After reversion, HR was increased in a dose-dependent manner for both reversers, but only IOI100 returned to baseline 10 minutes after reversal. Regarding SBP, the best performance was observed in ATI100, with no variations during the evaluation period. All antagonists/doses increased SI in comparison to GC, whereas IC had a significant increase in ATI100, IOI100, and IOI50. In the ECG evaluation, ATI50 and ATI100 were the most effective groups in reducing the occurrence of sinus arrest. The atrio-ventricular block was completely reversed with ATI100 and IOI100. The RR increased significantly in IOI100, with return to the baseline values, but was discrete for the other treatments. The intermediate (ATI50 and IOI50) and high (ATI100 and IOI100) doses of both antagonists were able to revert the sedative effects of dexmedetomidine with return to the baseline sedation score between 10 and 20 minutes. The time to ambulation was lower in ATI50, IOI100, and ATI100 groups, with the shortest time recorded in IOI100 (10.29 ± 05.46 minutes). In conclusion, 50 and 100 g/kg IV atipamezole and yohimbine are effective in completely reversing the sedative effects of dexmedetomidine and have a dose-dependent effect on the reversion of cardiovascular and respiratory effects in dogs sedated with dexmedetomidine.

Effects of detomidine constant rate infusion on blood glucose and lactate in sevofl urane anesthetized horses / Effects of detomidine constant rate infusion on blood glucose and lactate in sevoflurane anesthetized horses

Background: The drugs that promote sedation, analgesia, and anesthesia, as inhalatory agents, phenothiazines, benzodiazepines, alpha-2 adrenergic agonists, and opioids, can promote different kinds of side effects. The concept of a balanced anesthesia in equine was developed in order to minimize adverse effects inherent to anesthesia, creating a combination of lower doses of these drugs in comparison with the doses of each one used alone. Alpha-2-adrenoceptor agonists such as xylazine, detomidine, and others, are drugs used for standing sedation, analgesia, and reduction of volatile anesthetic requirement in the equine as well as an agent used to maintenance of arterial blood pressure during anesthesia. Alpha-2 agonists works stimulating receptors of autonomic neurons inducing reduction of heart rate, cardiac output and vascular resistance, hypertension, behavioral changes, and inhibition of insulin secretion. This reduction in insulin levels increases blood glucose concentration in horses due to its lower utilization in insulin-dependent tissues, as muscular and adipose tissues. Muscular tissue is capable to maintain a constant lactate production even in a well oxygenated environment in order to maintain its cellular activity, especially in cases when glucose is not available. To evaluate the effect on blood glucose and lactate, horses were submitted to one hour of detomidine c

Background: The drugs that promote sedation, analgesia, and anesthesia, as inhalatory agents, phenothiazines, benzodiazepines, alpha-2 adrenergic agonists, and opioids, can promote different kinds of side effects. The concept of a balanced anesthesia in equine was developed in order to minimize adverse effects inherent to anesthesia, creating a combination of lower doses of these drugs in comparison with the doses of each one used alone. Alpha-2-adrenoceptor agonists such as xylazine, detomidine, and others, are drugs used for standing sedation, analgesia, and reduction of volatile anesthetic requirement in the equine as well as an agent used to maintenance of arterial blood pressure during anesthesia. Alpha-2 agonists works stimulating receptors of autonomic neurons inducing reduction of heart rate, cardiac output and vascular resistance, hypertension, behavioral changes, and inhibition of insulin secretion. This reduction in insulin levels increases blood glucose concentration in horses due to its lower utilization in insulin-dependent tissues, as muscular and adipose tissues. Muscular tissue is capable to maintain a constant lactate production even in a well oxygenated environment in order to maintain its cellular activity, especially in cases when glucose is not available. To evaluate the effect on blood glucose and lactate, horses were submitted to one hour of detomidine c

Effects of detomidine constant rate infusion on blood glucose and lactate in devoflurane anesthetized horses

Background: The drugs that promote sedation, analgesia, and anesthesia, as inhalatory agents, phenothiazines, benzodiazepines, alpha-2 adrenergic agonists, and opioids, can promote different kinds of side effects. The concept of a balanced anesthesia in equine was developed in order to minimize adverse effects inherent to anesthesia, creating a combination of lower doses of these drugs in comparison with the doses of each one used alone. Alpha-2-adrenoceptor agonists such as xylazine, detomidine, and others, are drugs used for standing sedation, analgesia, and reduction of volatile anesthetic requirement in the equine as well as an agent used to maintenance of arterial blood pressure during anesthesia. Alpha-2 agonists works stimulating receptors of autonomic neurons inducing reduction of heart rate, cardiac output and vascular resistance, hypertension, behavioral changes, and inhibition of insulin secretion. This reduction in insulin levels increases blood glucose concentration in horses due to its lower utilization in insulin-dependent tissues, as muscular and adipose tissues. Muscular tissue is capable to maintain a constant lactate production even in a well oxygenated environment in order to maintain its cellular activity, especially in cases when glucose is not available. To evaluate the effect on blood glucose and lactate, horses were submitted to one hour of detomidine constant rate infusion during sevoflurane inhalatory anesthesia with controlled ventilation, in order to assess blood concentration of glucose and lactate. Materials, Methods & Results: Four adult horses were studied. Detomidine 20 µg.kg-¹ was used as premedication followed by an association of ketamine and diazepam intravenously as anesthetic induction. After intubation, sevoflurane was vaporized at approximately 2.3 V%. Mechanical ventilation was established. After stabilization, an intravenous continuous rate infusion (CRI) of detomidine 5 µg.kg.h-¹ was started. Venous blood samples were collected before premedication, prior to detomidine continuous infusion, 20, 40, and 60 min after beginning of infusion, in order to determination of glucose and lactate serum concentrations. After 60 min of detomidine infusion, the horses were allowed to recovery. There was statistical significant hyperglycemia in the horses under CRI of detomidine. There was no significant increase in blood lactate, despite of the hyperlactatemia in some animals. Discussion: Detomidine CRI of 5 µg.kg.h-¹ does increase blood glucose levels over normal values but not to levels that could be toxic to tissues, mainly CNS. With low levels of serum insulin, body tissues, mainly muscular and adipose tissues, are unable to capture this available blood glucose and these cells depend on lactate metabolism. The lactate serum concentrations below normal range observed in studied horses suggest that all lactate produced by the tissues is being utilized in the energetic metabolism. In according to many authors, lactate is produced and utilized for mitochondrias as energetic source even in fully oxygenated tissues, which seems to be what happened in this experiment. The present study helps to understand energetic metabolism in horses under general inhaled anesthesia with detomidine CRI, a selective alpha-2-adrenoceptor agonist. In order to better evaluate energetic metabolism during inhaled anesthesia under detomidine influence, other studies are suggested, as prolonged anesthesia duration to evaluate a longer adrenergic stimulus induced by detomidine. Besides, other investigations with detomidine CRI in horses submitted to surgical procedures could provide different responses in energetic metabolism.

Anestesia peridural com lidocaína isolada ou associada à clonidina: efeito cardiorrespiratório e analgésico em cães

Satisfactory analgesia has been related with epidural 2 adrenoceptor agonists in combination with local anesthetics. The aim of this study was to compare the analgesic and cardiopulmonary effects of lidocaine or lidocaine-clonidine epidural injections in healthy dogs. Dogs were randomly assigned to two groups of six animals each. The L group received lidocaine (5mg kg-1 L) and the C group lidocaine plus clonidine (10µg kg-1 C). Preanaesthetic medication was carried out with acepromazine (0.05mg kg-1 IV). Anaesthesia was induced and maintained with isoflurane by facial mask for epidural injection. Heart rate (HH), electrocardiography (ECG), respiratory rate (RR), systolic arterial blood pressure (SAP), rectal temperature (RT), blood gases, duration of anesthesia and sensitive block level were investigated. Statistical analysis was performed with ANOVA, Tukey test and paired t test. There was a decrease of HR at 15, 30 and 45 minutes after epidural injection in C group when compared with L group. Cardiac dysrhythmias did not observe in both treatments. The variables, SAP, RR, RT and blood gases did not differ between treatments. Duration of anesthesia was 71±13 and 75±26 minutes to L and C treatment, respectively, without difference between groups. The maximal extension of sensitive block was the fourth lumbar vertebra and the tenth thoracic vertebra in L and C treatment, respectively. In conclusion, the addition of clonidine to lidocaine in epidural anesthesia allowed more cranial sensory block in relation to the isolated use of local anesthetic, however, it produced bradycardia and did not prolong the duration of anesthesia.

Analgesia satisfatória tem sido relatada com a administração peridural de agonistas adrenérgicos em associação aos anestésicos locais. Objetivou-se, com este trabalho, avaliar o efeito analgésico e cardiorrespiratório da lidocaína isolada ou associada à clonidina via peridural lombossacra em cães. Seis cães foram submetidos a dois tratamentos, com intervalo mínimo de 15 dias entre cada avaliação. No tratamento L, foi empregada lidocaína 2% com vasoconstrictor (5mg kg-1) e, no tratamento C, a clonidina (10µg kg-1) foi associada à lidocaína, de modo a perfazer um volume final de 0,25ml kg-1. Os animais foram tranquilizados com acepromazina (0,05mg kg-1 IV) e mantidos sob anestesia com isofluorano em máscara facial durante a punção do espaço peridural. Foram mensuradas: frequência cardíaca (FC), parâmetros eletrocardiográficos (ECG), frequência respiratória (f), pressão arterial sistólica (PAS), gases sanguíneos, temperatura retal (T), duração e extensão do bloqueio anestésico. A estatística foi realizada com análise de variância, teste de Tukey e teste t pareado (P 0,05). A FC foi inferior aos 15, 30 e 45 minutos após a anestesia peridural, no tratamento C, em relação ao L. Arritmias não foram observadas em nenhum dos tratamentos. A PAS, a f, a T e os gases sanguíneos não diferiam entre os grupos. A duração do bloqueio anestésico não variou entre os tratamentos, sendo de 71±13 e 75±26 minutos, nos tratamentos L e C, respectivamente. Com relação à extensão do bloqueio, a altura máxima atingida foi a quarta vértebra lombar e a décima vértebra torácica, nos tratamentos L e C, respectivamente. Conclui-se que a associação da clonidina à lidocaína promoveu bloqueio anestésico mais cranial, quando comparado ao uso isolado do anestésico local, porém induziu bradicardia, além de não prolongar a duração do bloqueio anestésico.

Anestesia peridural com lidocaína isolada ou associada à clonidina: efeito cardiorrespiratório e analgésico em cães

Satisfactory analgesia has been related with epidural 2 adrenoceptor agonists in combination with local anesthetics. The aim of this study was to compare the analgesic and cardiopulmonary effects of lidocaine or lidocaine-clonidine epidural injections in healthy dogs. Dogs were randomly assigned to two groups of six animals each. The L group received lidocaine (5mg kg-1 L) and the C group lidocaine plus clonidine (10µg kg-1 C). Preanaesthetic medication was carried out with acepromazine (0.05mg kg-1 IV). Anaesthesia was induced and maintained with isoflurane by facial mask for epidural injection. Heart rate (HH), electrocardiography (ECG), respiratory rate (RR), systolic arterial blood pressure (SAP), rectal temperature (RT), blood gases, duration of anesthesia and sensitive block level were investigated. Statistical analysis was performed with ANOVA, Tukey test and paired t test. There was a decrease of HR at 15, 30 and 45 minutes after epidural injection in C group when compared with L group. Cardiac dysrhythmias did not observe in both treatments. The variables, SAP, RR, RT and blood gases did not differ between treatments. Duration of anesthesia was 71±13 and 75±26 minutes to L and C treatment, respectively, without difference between groups. The maximal extension of sensitive block was the fourth lumbar vertebra and the tenth thoracic vertebra in L and C treatment, respectively. In conclusion, the addition of clonidine to lidocaine in epidural anesthesia allowed more cranial sensory block in relation to the isolated use of local anesthetic, however, it produced bradycardia and did not prolong the duration of anesthesia.

Analgesia satisfatória tem sido relatada com a administração peridural de agonistas adrenérgicos em associação aos anestésicos locais. Objetivou-se, com este trabalho, avaliar o efeito analgésico e cardiorrespiratório da lidocaína isolada ou associada à clonidina via peridural lombossacra em cães. Seis cães foram submetidos a dois tratamentos, com intervalo mínimo de 15 dias entre cada avaliação. No tratamento L, foi empregada lidocaína 2% com vasoconstrictor (5mg kg-1) e, no tratamento C, a clonidina (10µg kg-1) foi associada à lidocaína, de modo a perfazer um volume final de 0,25ml kg-1. Os animais foram tranquilizados com acepromazina (0,05mg kg-1 IV) e mantidos sob anestesia com isofluorano em máscara facial durante a punção do espaço peridural. Foram mensuradas: frequência cardíaca (FC), parâmetros eletrocardiográficos (ECG), frequência respiratória (f), pressão arterial sistólica (PAS), gases sanguíneos, temperatura retal (T), duração e extensão do bloqueio anestésico. A estatística foi realizada com análise de variância, teste de Tukey e teste t pareado (P 0,05). A FC foi inferior aos 15, 30 e 45 minutos após a anestesia peridural, no tratamento C, em relação ao L. Arritmias não foram observadas em nenhum dos tratamentos. A PAS, a f, a T e os gases sanguíneos não diferiam entre os grupos. A duração do bloqueio anestésico não variou entre os tratamentos, sendo de 71±13 e 75±26 minutos, nos tratamentos L e C, respectivamente. Com relação à extensão do bloqueio, a altura máxima atingida foi a quarta vértebra lombar e a décima vértebra torácica, nos tratamentos L e C, respectivamente. Conclui-se que a associação da clonidina à lidocaína promoveu bloqueio anestésico mais cranial, quando comparado ao uso isolado do anestésico local, porém induziu bradicardia, além de não prolongar a duração do bloqueio anestésico.

Comparison of the effects of romifidine and an emulsion of amitraz on sedation and spontaneous locomotor activity of horses / Comparação dos efeitos da romifidina e de uma emulsão de amitraz na sedação e na atividade locomotora espontânea de eqüinos

Amitraz (AM) and romifidine (RMF), two alpha-2 adrenoceptor agonists, produce sedative effect and decrease spontaneous locomotor activity (SLA) of horses. The behavioral effects and sedation after intravenous injection of RMF (0.06mg/kg) or AM 0.1mg/kg (AM 0.1) or AM 0.4mg/kg (AM 0.4) were compared in horses. RMF caused head ptosis (HP) until 45 min. The lower AM dose induced HP from 45 to 60 minutes and from 120 to 150 minutes, and the higher dose induced HP until 180 minutes. Data concerning changes in SLA were not conclusive. RMF or AM 0.4 caused a greater sedation than AM 0.1 until 20 min. After 20 minutes, the sedation caused by AM 0.4 was greater than that of RMF or AM 0.1. Romifidine caused consistent sedation until 45 minutes. The amitraz emulsion produced a dose-dependent sedation until 180 minutes. Comparing to romifidine, the emulsion of amitraz induced a more substantial sedation. At dosages and dilution applied, amitraz is an effective sedative for horses.(AU)

Os agonistas de receptores adrenérgicos do tipo alfa-2 amitraz (AM) e romifidina (RMF) produzem efeito sedativo e reduzem a atividade locomotora espontânea (ALE) em eqüinos. Compararam-se os efeitos sedativos e comportamentais da injeção intravenosa de RMF (0,06mg/kg) ou AM 0,1mg/kg (AM 0,1) ou 0,4mg/kg (AM 0,4) em cavalos. RMF provocou ptose de cabeça (PC) por 45 minutos. O amitraz provocou PC entre 45 e 60 e entre 120 e 150 minutos com a dose menor, e por 180 minutos com a dose maior. Os dados relacionados à ALE não foram conclusivos. RMF ou AM 0,4 causaram sedação mais intensa que AM 0,1 até 20 minutos. Após 20 minutos, a sedação provocada pelo AM 0,4 foi mais intensa que para a RMF ou o AM 0,1. A romifidina causou sedação por 45 minutos. A emulsão de amitraz provocou sedação dose-dependente por 180 minutos. Em relação à romifidina, o amitraz produziu uma sedação mais consistente. Nas doses e na diluição aplicada, o amitraz é eficaz como sedativo para cavalos.(AU)

Effects of detomidine constant rate infusion on blood glucose and lactate in sevofl urane anesthetized horses / Effects of detomidine constant rate infusion on blood glucose and lactate in sevoflurane anesthetized horses

Background: The drugs that promote sedation, analgesia, and anesthesia, as inhalatory agents, phenothiazines, benzodiazepines, alpha-2 adrenergic agonists, and opioids, can promote different kinds of side effects. The concept of a balanced anesthesia in equine was developed in order to minimize adverse effects inherent to anesthesia, creating a combination of lower doses of these drugs in comparison with the doses of each one used alone. Alpha-2-adrenoceptor agonists such as xylazine, detomidine, and others, are drugs used for standing sedation, analgesia, and reduction of volatile anesthetic requirement in the equine as well as an agent used to maintenance of arterial blood pressure during anesthesia. Alpha-2 agonists works stimulating receptors of autonomic neurons inducing reduction of heart rate, cardiac output and vascular resistance, hypertension, behavioral changes, and inhibition of insulin secretion. This reduction in insulin levels increases blood glucose concentration in horses due to its lower utilization in insulin-dependent tissues, as muscular and adipose tissues. Muscular tissue is capable to maintain a constant lactate production even in a well oxygenated environment in order to maintain its cellular activity, especially in cases when glucose is not available. To evaluate the effect on blood glucose and lactate, horses were submitted to one hour of detomidine c

Background: The drugs that promote sedation, analgesia, and anesthesia, as inhalatory agents, phenothiazines, benzodiazepines, alpha-2 adrenergic agonists, and opioids, can promote different kinds of side effects. The concept of a balanced anesthesia in equine was developed in order to minimize adverse effects inherent to anesthesia, creating a combination of lower doses of these drugs in comparison with the doses of each one used alone. Alpha-2-adrenoceptor agonists such as xylazine, detomidine, and others, are drugs used for standing sedation, analgesia, and reduction of volatile anesthetic requirement in the equine as well as an agent used to maintenance of arterial blood pressure during anesthesia. Alpha-2 agonists works stimulating receptors of autonomic neurons inducing reduction of heart rate, cardiac output and vascular resistance, hypertension, behavioral changes, and inhibition of insulin secretion. This reduction in insulin levels increases blood glucose concentration in horses due to its lower utilization in insulin-dependent tissues, as muscular and adipose tissues. Muscular tissue is capable to maintain a constant lactate production even in a well oxygenated environment in order to maintain its cellular activity, especially in cases when glucose is not available. To evaluate the effect on blood glucose and lactate, horses were submitted to one hour of detomidine c

Chemical restraint of jaguars Panthera onca Linnaeus, 1758 with allometrically scaled doses of tiletamine, zolazepam, detomidine, and atropine / Contenção farmacológica de onças-pintadas Panthera onca Linnaeus, 1758 com a associação de tiletamina, zolazepam, detomidina e atropina calculados por extrapolação alométrica interespecífica

Chemical restraint of large felids is necessary for the handling, transportation, clinical assessment, and induction of anesthesia. The objective of this study was to evaluate the efficacy and safety of chemical restraint using a combination of tiletamine, zolazepam, detomidine, and atropine with interspecific allometric scaling doses in captive Panthera onca. There were ten males (two melanistic ones) and five females weighing between 35 and 80 kg. The evaluation of the chemical restraint protocol was carried out during routine management of the animals for physical examination, collection of blood and bone marrow samples, dental evaluation, and other procedures. During pre-established intervals, rectal temperature, heart rate, respiratory rate, nociception of thoracic and pelvic limbs, muscle relaxation and loss of the righting reflex were monitored. Loss of the righting reflex occurred at 8 ± 1.89 minutes post-injection (MPI). Respiratory rate returned at 77.6 ± 8.18 MPI; return of consciousness occurred at 112.6 ± 12.28 MPI, and complete recovery at 153 ± 12.47 MPI. There were no statistical differences between heart and respiratory rate means and oxyhemoglobin saturation. For rectal temperature, there was a significant reduction. The protocol analyzed was efficient for the chemical restraint of jaguars, enabling the manipulation, transportation, physical examination, dental evaluation, blood and bone marrow sample collection, and other minor invasive procedures of medium duration in these animals.

A contenção farmacológica de grandes felídeos é necessária para sua manipulação, transporte, avaliação clínica e indução anestésica. Por isso, objetivou-se avaliar a eficácia e a segurança da contenção farmacológica de exemplares de Panthera onca de cativeiro pela associação de tiletamina, zolazepam, detomidina e atropina, a partir de doses calculadas por meio de extrapolação alométrica interespecífica. Foram avaliados dez exemplares machos (dois melânicos) e cinco fêmeas, adultos, de Panthera onca. A contenção química foi realizada durante procedimentos de rotina dos animais para exame físico, colheita de sangue e medula óssea, avaliação odontológica e outros. Os parâmetros avaliados foram temperatura retal, frequências cardíaca e respiratória, nocicepção de membros torácicos e pélvicos, relaxamento muscular e reflexo de endireitamento. A perda da reação postural de endireitamento (RPE) ocorreu aos 8 ± 1,89 minutos pós-injeção (MPI). O retorno da RPE ocorreu em 77,6 ± 8,18 MPI, o retorno das reações conscientes em 112,6 ± 12,28 minutos e a recuperação total em 153 ± 12,47 MPI. Não foram encontradas diferenças estatísticas entre as médias de frequências cardíaca e respiratória e saturação parcial de oxiemoglobina. Em relação à temperatura retal, observou-se redução significativa. O protocolo avaliado foi eficiente para contenção farmacológica de todas as onças, viabilizando sua manipulação, transporte, exame físico, avaliação odontológica, colheita de sangue e medula óssea, e outros procedimentos pouco invasivos de média duração.