Influence of social stress on value of minimal anesthetic concentration of isuflurano in guan (Penelope obscura) captured in wildlife

Abstract

This study aimed to determine and evaluate whether there are differences in values of MAC in wildlife captured guan (Penelope obscura) under different conditions of social stress. This study used 27 bird species guan (P. obscura), divided into two groups: animals kept in the same enclosure (Collective Group) and animals kept in individual cages (Individual Group). The research was conducted at the Advanced Research Base of IBAMA, Painel/SC, and at the Clinical Veterinary Hospital of the “Universidade do Estado de Santa Catarina”, Lages/SC. The birds were captured using network trap with manual disarmament and transported to the Veterinary Hospital in cages. The animals were fasted for 2 to 6 hours before the procedure; anesthetic induction was performed with isoflurane for instrumentation. The isoflurane CAM was placed in the target value 1.3v% in the first animal of each group, and waited 15 minutes for the nociceptive (electric) stimulus, in the value of 50 hertz and 50mA, held in faradic form (3 consecutive simple stimuli, followed by 2 continuous stimuli). The stimulus was performed on the lateral side of the left pelvic limb in the tibiotarsal region, and the electrodes were fixed with a 22G needle at a distance of 5cm between them. The bird’s responses to the stimulus were considered positive (wing movements, head or vocalization) or negative (not presented movements of wings, head or vocalization) and the MAC value of the animal was recorded. Negative responses reduced next birds’ MAC value by about 10%, and MAC positive responses increased by about 10%. Statistical analysis was done by methods up and down and analyze quantal for MAC and paired t-test for equivalent or t-test for variances not equal variances for the physiological variables. At the end of the experiment, the birds were reintroduced in the same capture area. The MAC value of isoflurane in the Collective Group was 1.4v% and the Individual Group 1.9v% to 0.903atm. It is observed that guan (P. obscura) in the Collective Group showed lesser anesthetic resistance to isoflurane than the birds in the Individual Group, showing that some levels of social stress can influence the MAC values of the isoflurane.

>b<Determinação da concentração expirada de isofluorano frente a estímulo nociceptivo supramáximo em mico-leão-da-cara-dourada (>i<Leontopithecus chrysomelas>/i<)>/b<

“…No entanto, de acordo com a literatura consultada, não há relatos de concentrações expiradas ou de CAM para nenhuma espécie de mico-leão e algumas referências específicas e manuais acabam sugerindo valores de indução e manutenção muito acima destes valores (AYALA-BURBANO et al, 2017; BRAZ et al, 2019), sendo imprescindível a realização de um monitoramento intensivo em todas as fases da anestesia, principalmente no que se refere à frequência e qualidade respiratória e à hipotensão arterial que podem resultar em riscos graves aos animais. O método up-and-down foi utilizado para a determinação da concentração alveolar mínima (CAM) em outras espécies como cão e gato (BARLETTA; QUANDT; HOFMEISTER, 2016), galinha (Gallus gallus domesticus) (DA ROCHA et al, 2017) e jacu -Penelope obscura(LUNARDELI et al, 2019). No entanto, no estudo em questão, as limitações técnicas relacionadas à manutenção de uma ventilação completamente controlada sem escapes, dificuldade no controle da temperatura corporal e ausência de dados de hemogasometria impedem a caracterização desta determinação, sendo então trabalhado o resultado da concentração expirada média, conforme descrito na metodologia, e seus efeitos nos parâmetros fisiológicos.…”