Thoracic and heart biometrics of non-anesthetized agouti (Dasyprocta primnolopha Wagler, 1831) measured on radiographic images

Abstract

The agouti is a species intensively hunted throughout the Amazon and the semi-arid regions of northeastern Brazil. Considering the current trend in conservation management of wild species, the aim of this study was to determine the morphometric reference to the heart of agouti raised in captivity, based on thoracic and cardiac measurements in these animals. Thirty adult agoutis, 1 to 3 years of age, without clinical signs of cardiac disease were selected. The animals were physically restrained and radiographies in laterolateral (LL) and ventrodorsal (VD) recumbence were produced. The following measures were taken: the apicobasilar length of the heart (at the most cranial height of the Carina region to the heart apex) (AB), maximum width of the heart perpendicular to AB (CD), heart inclination angle (AIC), trachea inclination angle (AIT), distance from the right heart wall (DPTd), distance from the left heart wall (DPTe) and vertical depth of the thorax, and the ventral face of the vertebral column to the dorsal border of the sternum at the level of the trachea bifurcation (H). The ratios between AB/CD, AB/H and CD/H were also analyzed. To calculate the vertebral heart scale (VHS), the AB and CD measurements were laid over the thoracic vertebra starting at T4. Radiographic evaluation showed values consistent with those reported in small animals and some wild and exotic species. The main biometric values in the chest cavity and heart of agouti are arranged as follows: (1) The ratios between AB/H ratio and CD/H were not sensitive for identifying heart increases (p>0.05), while the ratio AB/CD was more sensitive in this identification (p<0.05); (2) AIC: 21.2±6.4 o (mean between male and famale); (3) AIT for males and females: 9.93±3.23° and 8.4±3.94°; (4) DPTd and DPTe for males: 0.97±0.40cm and 0.7±0.30cm; (5) DPTd and DPTe for females: 1.12±0.42cm and 01.02±0.43cm; (6) VHS for males and females: 7.75±0.48v e 7.61±0.34v; (7) The caudal vena cava (CVC) was visualized dorsal-cranially and located right of the midline. The data obtained allowed the acquisition of the first reference values for biometry of the heart of agoutis, contributing to better understanding of cardiac morphology and identification of cardiomyopathy in these animals. Os principais valores biométricos mensurados na cavidade torácica e cardíaca da cutia, estão dispostas da seguinte forma: (1) As relações entre AB/H e CD/H não foram sensíveis para identificar aumento do coração (p> 0,05), enquanto a proporção AB/CD foi mais sensível nesta identificação (p <0,05); (2) AIC: 21,2 ± 6.4 o (média entre machos e fêmeas); (3) AIT para machos e fêmeas: 9.93 ± 3.23° and 8.4±3.94°; (4) DPTd e DPTe para os machos: 0,97 ± 0,40 cm e 0,7 ± 0,30, (5) DPTd e DPTe para as fêmeas: 1,12 ± 0,42 e 01,02 ± 0,43; (6) VHS para machos e fêmeas: 7.75±0.48v e 7.61±0.34v; (7) A veia cava caudal (CVC) foi visualizada dorso-cranialmente e localizada à direita da linha média.Os dados obtidos permitiram a obtenção dos primeiros valores de referência para a biometria do coração de ...

Electrocardiographic Pattern of Agoutis (Dasyprocta prymnolopha) Chemically Contained by the Association of Ketamine and Xylazine

“…The P wave presented morphology and values, both in duration and in amplitude, very close to the parameters found for animals of the same species not anesthetized [7]. The amplitude of this wave showed no difference between the genders, whereas the duration showed statistical difference.…”

“…The values found for heart rate (HR) of anesthetized agoutis with Ketamine and Xylazine (113.25 ± 29.40 bpm for males and 124.60 ± 24.32 bpm for females) were lower than those found for this same non-anesthetized species (193.42 ± 25.39 bpm) [7]. These results suggest that such a difference may be related to stress during the physical restraint of nonanesthetized animals, leading to sinus tachycardia [13], or to the cardiovascular effects of Xylazine in sedated animals, which provoke a depression of the vasomotor center, increase of the vagal tone and of the baroreceptors activity, resulting in bradycardia [31,44].…”

“…Previous studies have demonstrated that the agoutis can be handled without previous chemical restraint for the performance of electrocardiographic exams, as it is a fast execution technique [7]. Wild animals, in general, need the implantation of anesthetic protocols, with the purpose of reducing stress during clinical-surgical and handling procedures, to avoid accidents with the animals and the people who handle them [4].…”

“…The amplitude of this wave showed no difference between the genders, whereas the duration showed statistical difference. There are no reports of this difference between genders in non-anesthetized agoutis [7]. Changes in the duration of the P wave may be related to variations in the size of animals of the same species as the dogs, where there is a diversity of races, differing in the size of the heart, thus affecting the time that the electrical impulse takes to depolarize the atria, resulting in the duration variations of this wave [13,18].…”

“…The agouti (Dasyprocta prymnolopha, Wagler, 1831) is a small mammal rodent found in almost all Brazilian territory [19], which has been shown to be an important animal model for scientific studies, including those for cardiovascular evaluation [7,32].…”