Left-dominant arrhythmogenic cardiomyopathy in a Fila Brasileiro dog.

Background: In human medicine, arrhythmogenic left ventricular cardiomyopathy was described as a primary disease of the heart characterized by fibroadipose replacement of the myocardium.. Case Description: We report the case of a dog, with history of syncope and irregular cardiac rhythm. Electrocardiogram, echocardiography, and a 24-hour Holter monitoring showed, respectively, the presence of premature ventricular complexes with right bundle branch block morphology, an increase of the left ventricle end-diastolic diameter with preserved fractional shortening and ejection fraction, and a sinus arrhythmia as baseline rhythm with supraventricular tachycardia episodes and ventricular complexes with left bundle branch block morphology. After the death of the canine, a postmortem examination showed cardiomegaly. Fibroadipose replacement of the septum and both ventricles, with left ventricle myocardial fibrosis, suggestive of previous necrosis, was observed. Conclusion: These findings are suggestive of left-dominant arrhythmogenic cardiomyopathy which, to the best of our knowledge, has not been described in veterinary medicine.

Findings suggestive of coronary microvascular dysfunction in cats with myocardial ischemia.

Background: Myocardial infarction (MI) is an important cause of death and disability among humans worldwide. Few studies have reported the occurrence of MI in small animals as well. Reports in human medicine indicate that up to 30% of patients with clinical signs compatible with myocardial ischemia suggestive of coronary disease exhibit normal epicardial arteries at angiography. These symptoms have been associated with a syndrome characterized by alterations in cardiac microvasculature, known as coronary microvascular dysfunction (CMD). Aim: This study aimed to describe the necropsy findings and clinical-pathological characterization (when available) of cats with histopathological findings suggesting CMD. Methods: Necropsy records of cats presenting histopathological diagnosis compatible with acute and/or chronic MI, with normal epicardial arteries and microvascular disorders were evaluated. Results: Twenty animals met the inclusion criteria. Eight cats (40%) exhibited findings compatible with mild hypertrophic cardiomyopathy (HCM) without left atrial enlargement, one (5%) presented restrictive cardiomyopathy, and another one (5%) had lesions consistent with histiocytoid cardiomyopathy. The remaining cats (50%) showed alterations compatible with severe HCM with left atrial enlargement. In all cases, epicardial arteries were normal (without obstruction). All the evaluated hearts exhibited myocardial multifocal fibrosis along with replacement of cardiomyocytes by adipose tissue and blood vessels with hyperplasia and hypertrophy of the muscular layer with protrusion of the nuclei of the endothelial cells. Conclusion: These findings suggest the presence of microvascular dysplasia of the coronary arteries. Further studies are necessary to confirm and clinically characterize these results.

Coronary anatomy of Commerson's dolphin (Cephalorhynchus commersonii) / Anatomia coronaria de la tonina overa (Cephalorhynchus commersonii)

The Commerson's dolphin (Cephalorhynchus commersonii) is an odontocete cetacean specie that lies in the waters of the southern hemisphere. With the aim of studying the course and distribution of Cephalorhynchus commersonii's coronary arteries, an exhaustive heart dissection was performed on one specimen. To the extent of our knowledge, and basing upon an extensive bibliographic research on the commersonii species, this is the first reported description of a Commerson's dolphin heart anatomy. Despite the fact that the analysis of a unique specimen does not allow to establish final conclusions, comparisons reveal broad similarities between Cephalorhynchus commersonii's coronary distribution and previous anatomical studies describing the heart of various marine diving mammals and the human fetus circulation. Diving mammals have developed an anastomotic system along evolution, in order to adjust their bodies to diving imposed conditions, and minimize the oxygen demand of the heart muscle. The present work begins with the identification of the patterns and similarities between Commerson's dolphin heart anatomy when compared to other odontecete species, to continue with an exhaustive description of the Commerson's dolphin coronary anatomy.

La tonina overa (Cephalorhynchus commersonii) es una especie de cetáceo odontoceto que se encuentra en las aguas del hemisferio sur. Con el objetivo de estudiar el curso y la distribución de las arterias coronarias de Cephalorhynchus commersonii, se realizó una disección exhaustiva del corazón de un ejemplar. Hasta donde sabemos, y basándonos en una extensa investigación bibliográfica sobre la especie, esta es la primera descripción informada de la anatomía de un corazón de este ejemplar. A pesar de que el análisis de una sola muestra no permite establecer conclusiones finales, las comparaciones revelan amplias similitudes entre la distribución coronaria de Cephalorhynchus commersonii, los estudios anatómicos previos que describen el corazón de varios mamíferos marinos buceadores, y la circulación del feto humano. Los mamíferos buceadores han desarrollado un sistema anastomótico a lo largo de la evolución para ajustar sus cuerpos a las condiciones impuestas por el buceo y minimizar la demanda de oxígeno del músculo cardíaco. El presente trabajo comienza con la identificación de los patrones y similitudes entre la anatomía del corazón de tonina overa en comparación con otras especies odontecetas, continuando con una descripción exhaustiva de la anatomía coronaria.

Tidal volume in mechanically ventilated dogs: can human strategies be extrapolated to veterinary patients?

This paper compares and describes the tidal volume (Vt) used in mechanically ventilated dogs under a range of clinical conditions. Twenty-eight dogs requiring mechanical ventilation (MV) were classified into 3 groups: healthy dogs mechanically ventilated during surgery (group I, n = 10), dogs requiring MV due to extra-pulmonary reasons (group II, n = 7), and dogs that required MV due to pulmonary pathologies (group III, n = 11). The median Vt used in each group was 16 mL/kg (interquartile range [IQR], 15.14-21) for group I, 12.59 mL/kg (IQR, 9-14.25) for group II, and 12.59 mL/kg (IQR, 10.15-14.96) for group III. The Vt used was significantly lower in group III than in group I (p = 0.016). The thoraco-pulmonary compliance was significantly higher in group I than in groups II and III (p = 0.011 and p = 0.006, respectively). The median driving pressure was similar among the groups with a median of 9, 11, and 10 cmH2O in groups I, II, and III, respectively (p = 0.260). Critically-ill dogs requiring MV due to the primary pulmonary pathology received a significantly lower Vt than healthy dogs but with a range of values that were markedly higher than those recommended by human guidelines.

Bartonella spp. in cats from Buenos Aires, Argentina.

In Argentina, data on the presence of members of the genus Bartonella is scarce. To increase knowledge about these zoonotic pathogens in this country, the presence and variability of Bartonella spp. was investigated in cats and dogs from Buenos Aires. Bartonella spp. was detected in 17.8% of cats, while all dogs tested negative by PCR and Reverse Line Blot. B. henselae was the most frequent species, being detected in 11.9% (14/101), while B. clarridgeiae was found in only 5.9% (6/101) of the cats. Afterwards, B. henselae isolates and positive blood samples were characterized by Multiple Locus Sequence Typing (MLST) and Multiple Locus Variable Number Tandem Repeats Analysis (MLVA). As result, four different MLST sequence types (ST) and eight MLVA profiles were identified. ST 1 was the most frequent variant found in cats, followed by ST 8. Interestingly, some of the MLVA profiles that were detected in this study have been previously associated with human disease, and represents a potential risk of infection. Veterinarians and physicians should consider the presence of these emerging pathogens in their diagnostic routine.

Electrocardiography in conscious releasable Andean condors (Vultur gryphus): reference panel and unusual findings.

Electrocardiography is a useful tool when included in healthcare protocols and is increasingly utilized for monitoring wild birds. However, the lack of reference data for many species is limiting the clinical value of this technique. In this study 26 Andean condors (Vultur gryphus) coming from rehabilitation and captive breeding programs were examined to determine electrocardiographic references prior to being released. Standard bipolar (I, II, and III) and augmented unipolar limb (aVR, aVL, and aVF) leads were recorded with birds under physical restraint. Five beats were analyzed on Lead II at 50 mm/sec and 1 cm = 1 mV to determine QRS complex morphology, cardiac rhythm, heart rate, P, PR, R, S, QRS, T, QT, and ST amplitude and/or duration. P and T wave configuration was determined for all leads, and Mean Electrical Axis (MEA) in the frontal plane was determined using leads I and III. Cardiac rhythm corresponded to regular sinus rhythm in 42% of the birds, with a relevant rate of sinus arrhythmia in 58%, and rS as the most common pattern (42%) for QRS complex in lead II. We found an influence of age and heart rate but not of sex on several ECG waves and intervals. Relevant ECG findings for studied Andean condors include a high rate of T(a), R', and U wave detection. Waves T(a) and R' were considered non-pathological, while the significance of U waves remains unclear. Our results provide a useful reference to improve clinical interpretation of full electrocardiographic examination in Andean condors.