Ruthnéa Aparecida Lázaro Muzzi

Echocardiographic indices in normal German shepherd dogs

Sixty clinically normal German shepherd dogs, 31 males and 29 females, ranging in age from 1 and 5 years and with a body weight ranging from 22 to 37.2 kg, were examined by the two-dimensional mode, M-mode, and Doppler echocardiography. In Doppler mode, the mitral valve flows were obtained, where the aim was to determine the velocity peaks and ratios of the E and A waves and the mitral E wave deceleration time. The velocity peaks were obtained for the tricuspid, pulmonary and aortic valves. On the left ventricular outflow tract flow, the time velocity integral and aortic cross-sectional area was used to calculate the cardiac output. A statistically significant correlation with the body weight was found for the systolic left atrial and diastolic aortic diameter on two-dimensional mode. On M-mode, there was a significant correlation between the body weight and the systolic left atrium and diastolic aortic dimension, systolic and diastolic left ventricular, septal and posterior wall dimensions. Doppler echocardiography showed that there was no significant correlation between the body weight and the mitral, tricuspid, pulmonary and aortic valves flows. These results demonstrate that it is important to know the normal echocardiographic values for German shepherd dogs because there are some characteristics peculiar to this particular breed. The data obtained is expected to be helpful for studies on small animal cardiology.

Heart rate variability parameters of myxomatous mitral valve disease in dogs with and without heart failure obtained using 24-hour Holter electrocardiography

Time-domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24-hour period, a four-hour period during sleep, and a four-hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five-minute segments during 24-hour Holter) and pNN50 (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24-hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24-hour evaluation period (P < 0.05). There were high correlations (canonical analysis) between Holter and echocardiography examinations when considering pNN50, SDANN, and LA/AO (left atrial to aortic root ratio) (r = 0.92; P < 0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN50 are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.

Estudo eletrocardiográfico de eqüinos da raça Mangalarga Marchador

For the electrocardiographic evaluation of Mangalarga Marchador breed horses, 60 electrocardiograms were recorded from clinically healthy equines aging from one to 28-year-old, being 39 females and 21 males. The heart rate tended to decrease with age and the amplitude of P wave increased with the growth of the animals. The duration of the QRS complex and the amplitude of S wave were greater in males than in females.

Fisioterapia após substituição artroscópica do ligamento cruzado cranial em cães: I - avaliação clínica, radiográfica e ultrassonográfica

The reconstruction of experimentally ruptured cranial cruciate ligament (CCL) under arthroscopic guidance and the effects of an early postoperative rehabilitation program by clinical, radiographic, and ultrasonographic exams were evaluated. Sixteen male mongrel dogs weighing from 19.2 to 26.3kg had the CCL experimentally ruptured and the stifle joint was stabilized by the use of an intracapsular arthroscopical technique with fascia lata as an autogenous graft. Eight dogs were included in a postoperative physiotherapy group and the other eight in a temporary immobilization group. From serial clinical, radiographic, and ultrasonographic examinations, no differences between groups were observed, although all dogs had showed signs of degenerative joint disease. Limb function was determined after surgery using force platform analysis, and the animals from physiotherapy group had significantly better results during rehabilitation period. It can be concluded that arthroscopic surgery for reconstruction of the cranial cruciate ligament is an efficient method to be used in dogs, in spite of not preventing the degenerative joint disease, and the physiotherapy has beneficial effects on early limb function during the rehabilitation period.

Alterations in the large peripheral circulation in dogs with heart failure.

The femoral artery is responsible for perfusion of a large muscular region that can be involved in the exercise intolerance shown by dogs with spontaneous heart failure. The objective of the present study was to evaluate blood flow in the femoral artery by transcutaneous duplex Doppler ultrasonography (TDU) in 50 healthy dogs and 50 dogs with spontaneous heart failure. The group of dogs with heart disease was divided according to the functional class of the heart failure. The TDU measurements were: peak systolic velocity (PSV), early retrograde (EDV) and end diastolic velocities (EnDV), mean velocity (MV), pulsatility index (PI), resistivity index (RI) and femoral flow volume (FFV). In healthy dogs, PSV and FFV were significantly higher than in dogs with heart disease. FFV was reduced mainly in patients with moderate and severe heart failure. TDU allowed for non-invasive detection and quantification of pathological alterations in peripheral hemodynamics.

Avaliação do ritmo cardíaco em cães da raça Boxer saudáveis pela eletrocardiografia contínua (Holter)

The cardiac rhythm in a 24-hour period of 12 dogs of the Boxer breed, clinically healthy, males and females, of different ages was evaluated. No differences between males and females in the minimum, medium and maximum cardiac rates were observed (P>0.05). The females showed larger number of ventricular premature complex than the males. The major disorder in the cardiac rhythm was the ventricular premature complex. Several dogs showed the R over T phenomenon. Episodes of ventricular bigeminy and trigeminy were also observed.

Heart rate variability and arrhythmias evaluated with Holter in dogs with degenerative mitral valve disease

As cardiopatias cursam com alteracoes do controle autonomico do coracao, resultando em taquicardia e consequente diminuicao na variabilidade da frequencia cardiaca (VFC). O objetivo deste estudo foi avaliar se o desenvolvimento de insuficiencia cardiaca secundaria a degeneracao valvar mitral (DVM) leva a alteracoes no controle autonomico do coracao, as quais podem ser determinadas pela eletrocardiografia continua (Holter). Caes foram distribuidos em grupos experimentais apos avaliacao clinica e ecocardiografica da seguinte maneira: controle (saudaveis; n=6), DVM sem insuficiencia cardiaca (n=8) e DVM com insuficiencia cardiaca (n=13). Arritmias e VFC foram determinadas pelo Holter. Animais portadores de DVM, quando comparados ao controle, apresentaram diminuicao significativa da potencia total, a qual e representativa de toda a VFC. Somente caes doentes e com insuficiencia cardiaca apresentaram incidencia elevada de arritmias supraventriculares, frequencia cardiaca aumentada, pequena quantidade de pausas superiores a 2,0s entre batimentos consecutivos, permanencia por mais tempo em taquicardia do que em bradicardia, diminuido indice de alta frequencia (indicativo de controle parassimpatico) e elevado indice de baixa frequencia (indicativo de controle simpatico e parassimpatico), quando comparados ao controle (p<0,05). Assim, conclui-se que, em caes portadores de DVM, as variaveis obtidas com o Holter apresentam-se alteradas devido ao desenvolvimento de insuficiencia cardiaca.

Comparison of two different methods for evaluating boar semen morphology

El objetivo de este estudio fue comparar el uso y la eficacia de dos tecnicas para evaluacion de la morfologia espermatica del semen porcino. La preparacion humeda con una solucion de formaldehido-citrato 2,94% y otra con el uso del colorante Rosa de Bengala. Se evaluaron 58 eyaculados de ocho verracos de alto desempeno, con edad entre 20 y 25 meses. Despues de la recogida del semen, la morfologia espermatica fue evaluada por dos tecnicas: la preparacion humeda convencional (solucion de formaldehido-citrato 2,94%) observada en microscopio de contraste de fase (1.000X de magnificacion) y la tecnica que utiliza un frotis preparado a partir del colorante Rosa de Bengala, analizado bajo un microscopio optico (400X de magnificacion). Se observo que el porcentaje de cambios de la cabeza, acrosoma, pieza intermedia y el total de cambios morfologicos no fueron diferentes (P > 0,05) entre los dos metodos. Se obtuvo un mayor numero de defectos de la cola (P < 0,05) con el uso de la tecnica de tincion con el colorante Rosa de Bengala en comparacion con la tecnica convencional. Esto se explica por el manejo en la preparacion del frotis que puede conducir a una mayor probabilidad de romper la cola, lo que conduce a la visualizacion de la anomalia cola rota. Se puede concluir que el uso del colorante Rosa de Bengala es un metodo eficaz para la evaluacion de la morfologia del semen porcino, senalando que importantes cuidados deben ser tomados, especialmente en la preparacion del frotis para que no ocurran cambios en los resultados, principalmente en los cambios de la cola.

Evaluation of aging on muscle blood flow in conscious healthy dogs by duplex Doppler ultrasonography

According to a study conducted on a population of 9,248 subjects, cardiac diseases are the second most prevalent cause of death in the dog. During the last decades, a common scenario has been the increase on life expectancy of dogs. The exact relationship between the negative modifications of cardiovascular function and the development of specific cardiovascular diseases is difficult to ascertain, and also, the effect of age per se on vascular impedance is important. It may result in limited cardiovascular reserve under conditions of increase demand in senescent animals. To evaluate the effect of age on the peripheral vasculature specifically, the objective of this study was to compare parameters of the regional blood flow as well as compliance and resistance indexes in the femoral arterial system of younger and older conscious healthy dogs by duplex Doppler ultrasonography. The data were collected from 16 mixed-breed dogs divided into two groups: young and old healthy dogs. In all dogs Doppler spectra blood flow patterns of the femoral artery were triphasic. Significant differences were not found between the parameters measured for young and old groups. Despite this, the average value of femoral flow volume in the older group was approximately 50% lower than the younger group. This finding could play an important role in limiting exercise response with age. In order to validate these speculations, further studies should be performed in aged dogs.

Índices ecoDopplercardiográficos de função ventricular esquerda em cães das raças Boxer e Schnauzer Miniatura

The index of myocardial performance (IMP) and others ecoDopplercardiographic indexes of ventricular function were evaluated in dogs of two different breeds and somatotypes. Twenty-four Miniature Schnauzer dogs averaging 8.4±1.6kg and 24 Boxer dogs averaging 25.1±2.6kg were used. IPM, ejection phase indexes, pre-ejection period, pre-ejection period/ejection time relation, and E wave deceleration time of mitral inflow showed correlation to body weight with significant differences between the breeds. Body weight was considered the main breed characteristic responsible for the observed differences. Ejection time (r=-0.51), pre-ejection time (r=-0.44), and isovolumetric relaxation time (r=-0.38) presented correlation with heart rate. The use of pre-ejection period/ejection time relation and ejection time correct by heart rate diminishes the influence of heart rate on the parameters.