Presumed normal hemodynamic values of the arteries in the final third period of gestation in bitches

Background: Doppler ultrasonography enables the investigation of vascular blood flow indexes in gestational assessment,being able to detect vascular resistances that can affect fetal and maternal circulation, such as cases of placental insufficiency, associated with fetal cerebral oxygenation deficit and fetal distress. The study aims to assume hemodynamicallynormal values in the final third of gestation in bitches, of the umbilical, uteroplacental, middle cerebral and internal carotidarteries, correlating the obtained Doppler velocimetric indexes, for the assessment of the feto-placental circulation, andprediction of fetal viability indexes, fetal centralization and probable date of delivery.Materials, Methods & Results: Thirty healthy bitches were examined in the final third of gestation (40-60 days). Thesewere evaluated by Doppler ultrasonography at 2 times (T): T1: between 40-50 days; T2: between 51-60 of gestation.At each time point, the peak systolic velocities (PSV) and end-diastolic velocities (EDV) used to obtain the pulsatility(IP) and resistivity (IR) indexes of the umbilical, uteroplacental, middle cerebral and internal carotid arteries of fetuseswere evaluated. Also, the systole/diastole (S/D) ratio of these vessels was evaluated. The data obtained were subjected toanalysis of variance and Tukey test, using a P value equal to 5%. A significant difference was observed between velocitiesand Doppler velocimetric indexes between the 2 phases of the gestational final third in all studied vessels. There was anincrease in the values of PSV and EDV and a decrease in the indexes, as the probable date of delivery approached. Theanalysis of the umbilical cord IR showed an increase from P1 to P2 (P < 0.05), while the IP decreased at the same time.For all studied variables there was a statistically significant difference (P < 0.05). In the uteroplacental...(AU)

Presumed normal hemodynamic values of the arteries in the final third period of gestation in bitches

Background: Doppler ultrasonography enables the investigation of vascular blood flow indexes in gestational assessment,being able to detect vascular resistances that can affect fetal and maternal circulation, such as cases of placental insufficiency, associated with fetal cerebral oxygenation deficit and fetal distress. The study aims to assume hemodynamicallynormal values in the final third of gestation in bitches, of the umbilical, uteroplacental, middle cerebral and internal carotidarteries, correlating the obtained Doppler velocimetric indexes, for the assessment of the feto-placental circulation, andprediction of fetal viability indexes, fetal centralization and probable date of delivery.Materials, Methods & Results: Thirty healthy bitches were examined in the final third of gestation (40-60 days). Thesewere evaluated by Doppler ultrasonography at 2 times (T): T1: between 40-50 days; T2: between 51-60 of gestation.At each time point, the peak systolic velocities (PSV) and end-diastolic velocities (EDV) used to obtain the pulsatility(IP) and resistivity (IR) indexes of the umbilical, uteroplacental, middle cerebral and internal carotid arteries of fetuseswere evaluated. Also, the systole/diastole (S/D) ratio of these vessels was evaluated. The data obtained were subjected toanalysis of variance and Tukey test, using a P value equal to 5%. A significant difference was observed between velocitiesand Doppler velocimetric indexes between the 2 phases of the gestational final third in all studied vessels. There was anincrease in the values of PSV and EDV and a decrease in the indexes, as the probable date of delivery approached. Theanalysis of the umbilical cord IR showed an increase from P1 to P2 (P < 0.05), while the IP decreased at the same time.For all studied variables there was a statistically significant difference (P < 0.05). In the uteroplacental...

Fetal distress during the last third of pregnancy in bitches - evaluation by Doppler ultrasound imaging

Background: Diagnostic ultrasound has revolutionized obstetric practice. Doppler techniques provided in vivo studies of the fetus-placental and uterus-placental circulations, in an increasingly precise manner. The assessment of fetal well-being is essential in obstetric practice, however, in veterinary medicine, there is a deficit of ultrasound parameters related to fetal distress. The main of this research was to determine the hemodynamic characteristics and behavior, through Doppler ultrasonography, of maternal-fetal vessels during the final third of gestation in bitches with fetuses under stress, as well as correlating them with each other and with fetal distress. Materials, Methods & Results: An observational, prospective study was carried out, in which 30 healthy bitches were examined, during the last third of pregnancy, with fetuses under fetal distress. Fetuses were evaluated in 2 stages: (1st): 50-54 days and (2nd): 55-60 days of gestation. All fetuses were calmly assessed, one by one, and fetal heart rate (FHR) was measured 5 times, for at least 3 min, to identify and confirm fetal distress. At least 3 fetuses were evaluated in each bitch and each measurement was performed in triplicate, setting a hemodynamic mean for each value evaluated. The flow pattern in the middle cerebral artery (MCA), internal carotid artery (ICA) and umbilical artery (UA) was evaluated. The analyzed vessel was initially visualized in B mode, followed by evaluation by color and spectral Doppler. The variables observed were: peak systolic velocity (PSV), end diastolic velocity (EDV) and the resistivity (RI) and pulsatility (PI) index, as well as the systole/diastole ratio (S/D). The analysis of RI and PI of the umbilical artery showed a statistically significant difference between the mean values found for the times studied, increasing from time 1 to time 2. For middle cerebral and internal carotid arteries, PI, RI and the relationship systole/diastole (S/D), showed a statistically significant difference between the mean values found for the times studied, decreasing from time 1 to time 2. Discussion: Fetal heart rate (HR) findings are considered normal above 200 beats per minute (bpm), only if preceded by acceleration and deceleration. This fact confirms the presence of fetal stress, by this parameter, for the fetuses in the present study. Corroborating the picture of fetal distress, another study concluded that HR tends to increase up to 20 days before delivery, a fact that did not occur in the study in question, where animals in the same gestational period were evaluated. Recent research has concluded that an elevated umbilical artery PI at 28 weeks of gestation, in the absence of fetal growth restriction or prematurity, is associated with some adverse cognitive findings in 12-year-olds children. In the present study, a progressive increase in this index was observed throughout the final third of pregnancy. Although the pups were not monitored after birth, this data serves as a warning for veterinarians, and can be useful in the assessment and diagnosis of possible postnatal nervous alterations. Like what was found in the present study, a study reported that from the 4th week to birth, the PSV of the umbilical artery (UA) increased almost linearly, with high significance. For the middle cerebral arteries, the PI showed a statistically significant difference between the mean values found for the times studied, however, decreasing throughout the final third of pregnancy.

Ocular echobiometry and resistivity Index of external ophthalmic artery in agoutis (Dasyprocta prymnolopha)

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. 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. 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. (AU)

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...

B-Mode and Doppler ocular ultrasound evaluation in healthy and positive dogs for visceral canine leishmaniasis

Background: The use of ultrasound examination in the evaluation of ophthalmopathies has been gaining more and more space within the ophthalmologic clinical routine. The hemodynamic study of ocular vascularization may anticipate future changes, aiding in the adequate establishment of therapeutic conduits. The objective of this study was to evaluate the structures of the ocular bulb and to perform the hemodynamic evaluation of the flow of the external ophthalmic artery of dogs with canine visceral leishmaniasis (CVL) correlating with healthy animals. Materials, Methods & Results: For this purpose, 100 animals were used, of these 70 positive for CVL and 30 healthy animals, submitted to B-mode and Doppler ultrasound examination. Two-dimensional evaluation included identification of ocular changes and biometry of the following segments: axial length (M1), anterior chamber depth (M2), lens thickness (M3), lens length (M4), glass chamber depth (M5), optical disc length (M6) and optic nerve length (M7). The Doppler velocimetric evaluation included the identification and hemodynamic evaluation of the external ophthalmic artery, being measured: systolic peak velocity (SPV), final diastolic velocity (FDV), resistivity index (RI) and pulsatility index (PI). Ophthalmopathies were frequent in animals with leishmaniasis in both right (91.42%) and left (29.14%) eyes, with identification of capsular cataract, lens dislocation, retinal detachment and lens rupture. No significant statistical difference (P > 0.05) was observed when comparing the biometric values between the right and left eyes of the animals with CVL, as well as for the measurements between healthy and CVL animals. Hemodynamic indexes of the flow of the external ophthalmic artery presented narrow limits for the right and left eyes of the positive animals, not statistically...

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)

Standard strain and strain rate by two-dimensional speckle tracking in agoutis (Dasyprocta prymnolopha) anesthetized with ketamine and xylazine

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).[...]

Standard strain and strain rate by two-dimensional speckle tracking in agoutis (Dasyprocta prymnolopha) anesthetized with ketamine and xylazine

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).[...](AU)

Electrocardiographic pattern of agoutis (Dasyprocta prymnolopha) chemically contained by the association of ketamine and xylazine

Background: The agouti (Dasyprocta prymnolopha, Wagler, 1831) is an existing wild rodent in almost all of Brazil, usedas a biological model in several scientific studies. Veterinary cardiology has showed great advances in the diagnostic areadue to the possibility of cardiac evaluation by non-invasive methods. For the practice of scientific or handling proceduresin wild animals, chemical containment is essential. Thus, it is important to know the effect of anesthetic protocols on thecardiovascular system, observed through complementary tests, such as the electrocardiogram. The objective of this studywas to describe the computerized electrocardiographic tracing of agoutis chemically contained by the association of Ketamineand Xylazine.Materials, Methods & Results: Eighteen male and female clinically healthy animals, aged among 2 years, submitted todigital electrocardiographic examination, were used. The device used to obtain the tracing was the veterinary electrocardiograph(Electrocardiogram Acquisition Module for Computer) - Brazilian Electronic Technology (TEB). The analysiswas always made from derivation II (DII). Chemical containment was performed by the combination of Ketamine andXylazine, intramuscularly. The results showed that the heart rate for males was on average 113.25 bpm, while for femalesthe value of 124.60 bpm was observed, and there was no significant difference between the genders (P > 0.05). The meanweight of males was 2.31 kg and for females 2.28 kg; there was no statistical difference for this variable (P > 0.05). Forthe QRS duration of 46.14 ± 5.05 ms (males) and 44.66 ± 5.94 ms (females) and PR interval of 79.94 ± 12.01ms (males)and 84.29 ± 12.37ms (females), there was no statistical difference (P > 0.05). The amplitude of the R wave of 0.42 ± 0.31mV (males) and 0.36 ± 0.22 mV (females) showed no statistical difference (P > 0.05). The T wave showed itself bothnegative (10 animals) [...]

Electrocardiographic pattern of agoutis (Dasyprocta prymnolopha) chemically contained by the association of ketamine and xylazine

Background: The agouti (Dasyprocta prymnolopha, Wagler, 1831) is an existing wild rodent in almost all of Brazil, usedas a biological model in several scientific studies. Veterinary cardiology has showed great advances in the diagnostic areadue to the possibility of cardiac evaluation by non-invasive methods. For the practice of scientific or handling proceduresin wild animals, chemical containment is essential. Thus, it is important to know the effect of anesthetic protocols on thecardiovascular system, observed through complementary tests, such as the electrocardiogram. The objective of this studywas to describe the computerized electrocardiographic tracing of agoutis chemically contained by the association of Ketamineand Xylazine.Materials, Methods & Results: Eighteen male and female clinically healthy animals, aged among 2 years, submitted todigital electrocardiographic examination, were used. The device used to obtain the tracing was the veterinary electrocardiograph(Electrocardiogram Acquisition Module for Computer) - Brazilian Electronic Technology (TEB). The analysiswas always made from derivation II (DII). Chemical containment was performed by the combination of Ketamine andXylazine, intramuscularly. The results showed that the heart rate for males was on average 113.25 bpm, while for femalesthe value of 124.60 bpm was observed, and there was no significant difference between the genders (P > 0.05). The meanweight of males was 2.31 kg and for females 2.28 kg; there was no statistical difference for this variable (P > 0.05). Forthe QRS duration of 46.14 ± 5.05 ms (males) and 44.66 ± 5.94 ms (females) and PR interval of 79.94 ± 12.01ms (males)and 84.29 ± 12.37ms (females), there was no statistical difference (P > 0.05). The amplitude of the R wave of 0.42 ± 0.31mV (males) and 0.36 ± 0.22 mV (females) showed no statistical difference (P > 0.05). The T wave showed itself bothnegative (10 animals) [...](AU)