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Background : Research has increasingly focused on wild animals, and this requires the use of chemical restraints that are safe for both the species and the team involved. Dextroketamine is the levorotatory ketamine isomer that has been used on domestic species as an alternative that is more potent and safer than the racemic form. Midazolam is a benzodiazepine that induces muscle relaxation and minimal cardiorespiratory changes. The purpose of this study was to determine whether a combination of dextroketamine and midazolam can be safely used for the chemical restraint of agoutis ( Dasyprocta prymnolopha ), and the effects of this protocol on physiological and anesthetic parameters. Materials, Methods & Results : This study was carried out under conditions similar to those found for wild animals in captivity or in zoos. A pre-evaluation was also made to compare the baseline values of this study with those of other studies on the same species. Nine healthy adult agoutis were used, weighing between 1.5 kg and 2 kg. All the parameters were evaluated and recorded before the drugs were applied, and this was considered the baseline moment (M0). The dextroketamine and midazolam combination was then administered intramuscularly, in the same syringe, in dosages of 15 mg/kg and 0.5 mg/kg, respectively. Successive evaluations were made every 10 min over a period of 40 min (M10, M20, M30 and M40). The latency stage of anesthesia, effective stage and recovery stage were observed. Heart rate (HR) and breathing frequency ( f ), body temperature (BT), systolic blood pressure (SBP), peripheral oxygen saturation (SpO 2 ) and electrocardiogram were recorded. HR and SBP showed no significant difference between moments. Breathing frequency ( f ) showed a significant decline at M10 and M20 when compared to baseline values ( P < 0.05). BT decreased from the moment the drugs were administered until the end of the experimental period, with a significant difference between M0 and M40, and M10 and M40 ( P < 0.05). SpO 2 decreased significantly at M10 and M20 when compared to baseline values ( P < 0.01). There was no significant difference in the duration and amplitude of the P wave or in the duration of the QRS complex, QT interval and amplitude of the R wave. Regarding the PR interval, there was a significant difference only at M40 when compared to baseline values ( P < 0.05). No arrhythmia was observed. An evaluation of the effects of anesthesia indicated that the animals had an average latency stage of 2 min, an effective stage of 87 min, and an average recovery stage of 111 min. Adverse effects observed during the anesthetic recovery period consisted of tearing, salivation, tongue protrusion, vocalization and chewing reflex. Discussion : The results indicated that the association of anesthetic drugs under study caused minimal changes in the animals’ physiological parameters, except for the breathing frequency ( f ), which declined considerably, resulting in a reduction in SpO 2 , which was compensated during the study. In addition, there was a rapid onset of restraint and a satisfactory duration. Thus, from the cardiorespiratory standpoint, the combination of dextroketamine and midazolam in the doses used provides a safe anesthetic protocol for agoutis ( Dasyprocta prymnolopha ) and can be used for the chemical restraint of these animals for the performance of non-invasive and short-term procedures.

Background : Veterinary Ophthalmology provides complementary information for the diagnosis of ocular pathologies. Studies in wild species are essential. Among the diagnostic techniques in ophthalmology, two-dimensional ultrasonography stands out. The agouti is a rodent belonging to the Dasyproctidae family that has been widely used as an experimental model. For these animals, sight is one of the crucial senses for their survival. The aim of this study was to evaluate the effectiveness of the two-dimensional ocular ultrasound technique to obtain anatomical measurements and the external ophthalmic artery resistivity index, presumably normal in the species Dasyprocta prymnolopha . Materials, Methods & Results: Forty eye bulbs of 20 adult rodents of the species were evaluated by ultrasonography. In these animals, B-mode echobiometry was performed using the transpalpebral approach and the hemodynamic study of the external ophthalmic artery using the color Doppler technique. All examinations were initiated by the left eye bulb and all measurements were performed by only one examiner. The collected data related to echobiometry were analyzed using Bioest 5.0 for Windows. Initially, normality was tested using the Shapiro-Wilk test for each parameter, then the paired t -test was performed, comparing right and left eyes, and a significance level of 5% ( P < 0.05) was adopted. Based on the methodology used, the following values were obtained for the right and left eyeballs, respectively: anterior chamber thickness - mean of 1.28 ± 0.3 mm and 1.22 ± 0.1 mm; lens thickness - 8.27 ± 0.9 mm and 8.11 ± 0.9 mm; vitreous chamber thickness - 5.35 ± 0.48 mm and 5.30 ± 0.47 mm and axial length - 12.7 ± 0.9 mm and 13 ± 0.68 mm. The mean external ophthalmic artery resistivity values were 0.4305 ± 0.0390 and 0.4258 ± 0.0387 (right and left eye, respectively), characterizing a low resistance. There was no statistical difference between the right and left eyeballs in any of the studied parameters. Discussion : The use of the convex transducer was feasible, promoting adequate contact with the ocular surface and images of satisfactory quality for obtaining measurements, similar to what was observed in studies evaluating the ocular biometry of primates and dogs. The anterior chamber thickness values in this experiment did not differ statistically between the antimers, as well as observed for dogs. The data obtained for lens thickness did not differ statistically for antimers, like those obtained for other rodent species evaluated with the same methodology. The mean values of vitreous chamber thickness were like those observed in chinchillas but correspond to about half of that obtained for capybaras. In this study, the external ophthalmic artery was characterized in all animals, but obtaining the spectral tracing was difficult due to its fine caliber. In wild animals, and especially in wild rodents, there are few data reporting the resistivity of the ophthalmic artery, and there is a lack of studies, which can be explained by the behavioral characteristics of defense and by the high susceptibility to stress in capture, since the performing the technique requires, as in other procedures, the use of chemical containment. Keywords: Doppler flow, ultrasound, eye, agouti.

Background: The agouti (Dasyprocta prymnolopha, Wagler, 1831) is a wild rodent widely found throughout America which has stood out as a good animal model for scientific investigations. The aim of this study was to study the cardiovascular function of chemically contained agoutis, by performing echocardiographic examinations and measuring Strain and Strain Rate by Speckle Tracking to obtain reference values for the species and verify the applicability of these animals as models for the study of cardiovascular changes in humans.Materials, Methods & Results: It was selected 16 animals, sedated by the combination of ketamine hydrochloride and xylazine and submitted to transthoracic echocardiography. To obtain the standard measurements, B, M and Doppler mode images were taken. The analysis of the radial and longitudinal myocardial deformation of the left ventricle was carried out. The right parasternal window was used for access to the short cardiac axis and the left for access to the long axis. Six radial profiles of strain (ST) and Strain rate (SR) values were obtained, corresponding to the mean of the values for each segment. A total of 18 myocardial segments were analyzed for each specimen and the mean values were used to compose the statistical analysis. The comparison of the means between the genders did not show statistical difference, being the other statistical treatments based on the total sample of 16 animals. The variables that showed statistically significant correlation coefficients in relation to weight were: LA, LA/AO, HR, AVmax, E’ wave, E/IVRT (P > 0.05). HR showed a positive correlation with IVSd (r = 0.51), EPSS (r = 0.55) and E’ wave (r = 0.68); negative with IVRT (r = - 0.41), A wave (r = - 0.54), AVmax (r = - 0.53) and Pmax (r = - 0.65).Discussion: Although presumptively normal echocardiographic values were reported for not anesthetized agoutis, this was the first study to show the measurement of these variables for chemically contained agoutis, in addition to the use of Strain and strain rate by speckle tracking in the assessment of cardiac function. The sudden exposure of an external stimulus (environmental or physical) to which the body is not adapted can trigger an acute stress, and its effects may interfere significantly in the measurement of hemodynamic variables, justifying the need for chemical containment. The values found for the thickness of agoutis cardiac walls and chambers obtained in M mode, both in systole and in diastole, when compared with mammals of different size, confirm the positive linear correlation between body weight and cardiac dimensions for the various evaluated parameters. The velocity obtained by the Strain radial for the apical systolic peak was slightly lower than that obtained for the basal systolic peak, while the opposite was observed for the circumferential Strain, which showed apical peak greater than the basal peak, also to the found for human beings. The values obtained for circumferential, radial and longitudinal strain for agoutis were within the ranges of normality observed in healthy domestic animals and humans.