Leonardo Augusto Lopes 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.

Ultra-sonografia bidimensional convencional, de alta resolução e tridimensional no acompanhamento da gestação em cadela

Gestational period in a bitch, after natural mating with a normal dog, was evaluated by two-dimensional conventional, high-resolution two-dimensional and three-dimensional ultrasonography. High-resolution two-dimensional ultrasonography show better image and provides early diagnosis of pregnancy (15 days) in comparison to conventional one (20 days). Three-dimensional ultrasonography was use to evaluate fetal morphology during late gestation period, however its application is still limited.

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.

Electrocardiographic study in the American Quarter Horse breed

An evaluation of the electrocardiographic profile of 50 clinically healthy Quarter Horses, with ages ranging from six months to 28 years old, 34 females and 16 males, was performed. Heart rate has not decreased with age, and duration of the QRS complex increased with the growth of the animal. The amplitude of the S and T1 waves were higher in male subjects than in female Quarter Horses.

Técnica de fistulação e canulação do rúmen em bovinos e ovinos

A surgical technique for rumen fistulation and cannulation was developed for animal nutritional studies. The surgical method was used to cannulated 25 adult cows and eight lambs. The permanent fistula was made in the middle of the left paralumbar fossa in a one-stage operation. It was performed the spreading of the abdominal muscle layers and the sutures from the rumen to the peritoneum and to the skin, and the rubber cannula was inserted into the rumen wall. No severe complication was observed in ruminal cannulation, but minor leakages were observed in some animals. The cannulas had a long functional life and permited convenient sampling of digesta.

Diagnóstico ecodopplercardiográfico da fibrose crônica da válvula mitral em cão

A ten year-old male Poodle dog, weighing 3kg, was referred to the Veterinary Hospital of UFMG due to nocturnal coughing, exercise intolerance, weakness and weight loss. Physical examination revealed pale mucous membranes, prolonged capillary refill time, holosystolic regurgitant murmur at left apex and signs of congestive heart failure. M-mode, two-dimensional, and Doppler echocardiography revealed mitral chronic valvular disease

Comparison of the proximal tibial angles between Labrador Retrievers and other dog breeds with and without cranial cruciate ligament rupture

The influence of the proximal tibia conformation in the rupture of the cranial cruciate ligament (CCL) in dogs is still controversial, especially in Labrador Retrievers. The aim of this study was to compare the angles of the proximal tibia between Labrador Retrievers and other large breeds of dogs, both groups with and without CCL rupture. Radiographic images of 64 stifle joints were obtained and divided into four groups of 16 images. Group 1 consisted of Labrador dogs without orthopedic disorders, group 2 consisted of Labrador dogs with CCL rupture, group 3 consisted of dogs of various large breeds without orthopedic disorders, and group 4 consisted of dogs of various large breeds with CCL rupture. The radiographs were performed in mediolateral projection with the stifle joint positioned at an approximate angle of 135°. The tibial plateau angle showed an overall average of 22.17°±4.20°, and there was no statistically significant difference between the groups. The patellar ligament angle in relation to the tibial plateau had a mean of 103°±4.20°, and there was a significant difference between groups 1 and 4. The patellar ligament angle in relation to the common tangent at the tibiofemoral contact point showed an average of 99.06°±6.08°, and there was no difference between the groups. The patellar ligament insertion angle had an overall average of 51.45°±5.06°, and there was a significant difference between the two groups of normal dogs and two groups of ruptured dogs. In conclusion, the tibial plateau angle, the patellar ligament angles and the patellar ligament insertion angle do not seem to be predisposing factors for rupture of the CCL in Labrador Retriever dogs. In general, there seems to be no relationship between the angles of the proximal tibia and the CCL rupture in dogs.

QT interval in healthy dogs: which method of correcting the QT interval in dogs is appropriate for use in small animal clinics?

The electrocardiography (ECG) QT interval is influenced by fluctuations in heart rate (HR) what may lead to misinterpretation of its length. Considering that alterations in QT interval length reflect abnormalities of the ventricular repolarisation which predispose to occurrence of arrhythmias, this variable must be properly evaluated. The aim of this work is to determine which method of correcting the QT interval is the most appropriate for dogs regarding different ranges of normal HR (different breeds). Healthy adult dogs (n=130; German Shepherd, Boxer, Pit Bull Terrier, and Poodle) were submitted to ECG examination and QT intervals were determined in triplicates from the bipolar limb II lead and corrected for the effects of HR through the application of three published formulae involving quadratic, cubic or linear regression. The mean corrected QT values (QTc) obtained using the diverse formulae were significantly different (ρ<0.05), while those derived according to the equation QTcV = QT + 0.087(1- RR) were the most consistent (linear regression). QTcV values were strongly correlated (r=0.83) with the QT interval and showed a coefficient of variation of 8.37% and a 95% confidence interval of 0.22-0.23 s. Owing to its simplicity and reliability, the QTcV was considered the most appropriate to be used for the correction of QT interval in dogs.

Fixação esquelética externa em fratura tarsometatársica de seriema (Cariama cristata): relato de caso

An adult red-legged seriema (Cariama cristata) was referred for examination with history of trauma by capture. The physical examination revealed lameness in the right pelvic limb, sensibility to touch and open fracture of tarsumetatarsus. The treatment was done with surgical closed reduction using a external skeletal fixator type II with acrylic connecting bar. The surgical technique applied was satisfactory for the treatment of the fracture of tarsumetatarsus, since there was bone healing and functional return of the limb at 60 days after surgery.

Assessment of left atrial function in dogs with myxomatous mitral valve disease by biplane simpson’s method

The relationship between the diameter of the left atrium (LA) and aorta (Ao) is considered as a prognostic factor in chronic mitral valve disease. As the left atrium is a three-dimensional structure, methods based on measurement of the chamber volume can be more accurate than linear methods.The aim of this study was to assess the feasibility of measuring LA volume with 2D echocardiography using the biplane modified Simpson (SIMP) method in 33 dogs with various classes of myxomatous mitral valve disease (MMVD), as well as to present values of LA function using the atrial diastolic and systolic volume indices (ADVI and ASVI), cardiac index (ACI) and atrial ejection fraction (AEF). We observed agreement among the LA/Ao ratio and the atrial volume indices (ADVI and ASVI) and the ACI, suggesting that the values of the variables increase as the LA/Ao ratio increases due to atrial remodeling that accompanies MMVD progression. The data demonstrated a good assessment of atrial function, allowing a better understanding of LAs role in the pathophysiology of MMVD.