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peer reviewed | OBJECTIVE: To assess blood oxygen binding in calves with diarrhea. ANIMALS: 22 dairy and 26 double-muscled calves with diarrhea, 31 healthy dairy calves and 37 healthy double-muscled calves. PROCEDURE: Severity of disease, including the ability of affected calves to stand, was evaluated. Hydration and signs of depression were scored. Venous and arterial blood samples were collected, and 2,3-diphosphoglycerate, ATP, chloride, inorganic phosphate, lactate, pyruvate, total protein, albumin, and hemoglobin concentrations, and Hct, pH, Pco2, and PO2 were determined. Oxygen equilibrium curves (OEC) were constructed under standard conditions, and oxygen extraction ratios were calculated. RESULTS: Recumbent calves of both breed-types were more dehydrated and had more severe signs of depression than ambulatory affected calves. In both breed-types, hemoglobin oxygen affinity was increased in calves with diarrhea, compared with healthy calves, as indicated by a decrease in standard partial oxygen pressure (P50). Diarrhea induced hypocapnia and hypothermia in the most severely affected calves, which counteracted the acidosis-induced right shift in arterial and venous OEC. Arterial and venous P50 were significantly less in double-muscled calves with diarrhea than healthy calves, whereas P50 for affected dairy calves were similar to those of healthy calves. Except in the most severely affected dairy calves, oxygen extraction ratio was significantly less in calves with diarrhea, compared with healthy calves. CONCLUSIONS AND CLINICAL RELEVANCE: Release of oxygen from blood may be impaired in calves with diarrhea, depending on the effect of the disease on certain blood biochemical variables.

peer reviewed | OBJECTIVE: To assess morphologic and metabolic abnormalities in dogs with early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP). ANIMALS: 7 Beagles. PROCEDURE: Plasma carnitine concentrations were measured before and after development of ELVD induced by RRVP. At the same times, transvenous endomyocardial biopsy was performed, and specimens were submitted for determination of myocardial carnitine concentrations and histologic, morphometric, and ultrastructural examination. RESULTS: In 4 dogs in which baseline plasma total carnitine concentration was normal, RRVP induced a decrease in myocardial total and free carnitine concentrations and an increase in myocardial esterified carnitine concentration. In 3 dogs in which baseline plasma total carnitine concentration was low, plasma and myocardial carnitine concentrations were unchanged after pacing. Structural changes associated with pacing included perinuclear vacuolization in 3 dogs. Morphometric analyses indicated there was a decrease in myofiber cross-sectional diameter and area following pacing. Electron microscopy revealed changes in myofibrils and mitochondria following pacing. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that moderate to severe alterations in myocyte cytoarchitecture are present in dogs with ELVD induced by RRVP and that in dogs with normal plasma carnitine concentrations, myocardial carnitine deficiency may be a biochemical marker of ELVD. Results also indicated that transvenous endomyocardial biopsy can be used to evaluate biochemical and structural myocardial changes in dogs with cardiac disease.

peer reviewed | OBJECTIVE: To characterize the accuracy of an ultrafine 99m-technetium-labeled carbon dry aerosol for use in assessment of regional ventilation in calves with pulmonary dysfunction. ANIMALS: 7 Belgian White and Blue calves. PROCEDURE: The ultrafine aerosol was assessed by comparing deposition (D) images with ventilation (V) images obtained by use of 81 m-krypton (81mKr) gas via D-to-V ratio (D:V) image analysis in calves during spontaneous breathing (SB) and during experimentally induced pulmonary dysfunction (ePD). RESULTS: Mismatching index (LrTot) calculated on the D:V images revealed a good match (LrTot, 0.96 +/- 0.01) between D and V distribution patterns in calves during SB. Calculation of the ultrafine aerosol penetration index relative to 81mKr (PIRel) revealed preferential distribution of the ultrafine aerosol in lung parenchyma (PIRel, 1.13 +/- 0.11). In ePD, heterogeneity in the D:V distribution was observed (LrTot, 0.78 +/- 0.10) as a result of ultrafine aerosol particles impaction in airways as indicated by PIRel (0.66 +/- 0.16) and a proportion of pixels more radioactive in D images, compared with V images, that was located in the central part of the lung (475 +/- 77% in ePD vs 32.8 +/- 5.7% in SB). However, this central deposition did not prevent visual examination of the entire ventilated lung. CONCLUSIONS AND CLINICAL RELEVANCE: The ultrafine aerosol appears suitable for use in examination of ventilated parts of lungs of cattle, even those with impaired pulmonary function. However, airway impaction of ultrafine aerosol particles impedes the quantification of regional ventilation in cattle with abnormal lung function.

peer reviewed | OBJECTIVE: To determine whether dobutamine stress tests (DST) can be used to detect cardiac dysfunction in dogs with early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP). ANIMALS: 7 adult male Beagles. PROCEDURE: A pacemaker was surgically implanted in each dog at the level of the right ventricular apex. Electrocardiography, Doppler sphygmomanometry, and Doppler echocardiography were performed before and during a DST prior to activation of the pacemaker and every 3 to 4 days during the period of RRVP. Dobutamine stress tests were performed by infusing dobutamine at incremental dosages ranging from 12.5 to 42.5 microg/kg of body weight/min. RESULTS: Clinical signs of congestive heart failure were not observed during the pacing period. However, all dogs developed ELVD associated with significant changes in values for most Doppler echocardiographic variables obtained prior to DST Adverse cardiac effects were not detected during DST. Most Doppler echocardiographic indices of cardiac function were significantly altered in response to dobutamine infusion during the pacing period, compared with prepacing values. However, a dobutamine-induced 2-fold increase in cardiac output was maintained. CONCLUSIONS AND CLINICAL RELEVANCE: Dobutamine stress tests can be safely performed in dogs with experimentally induced ELVD. Dobutamine stress tests may be a sensitive, noninvasive diagnostic method, complementary to standard clinical examinations, for detection of early cardiac dysfunction in dogs asymptomatic for dilated cardiomyopathy.

Os objetivos foram contribuir com dados sistemáticos relativos à posição do timo em relação ao esqueleto, sua respectiva topografia, morfometria e organização, além do número, origem e tipos dos vasos arteriais associados à vascularização do órgão. Para tanto, foram utilizados 26 fetos caprinos da raça Saanen para o estudo macroscópico, cujos vasos arteriais foram injetados com solução marcadora de Neoprene látex 450, e 4 fetos para o estudo microscópico da estrutura da parede vascular das artérias tímicas. As partes torácica e cervical do timo mostraram uma vascularização própria, através de ramos diretos e indiretos, sendo que as artérias tímicas apresentaram estrutura predominante de fibras elásticas na camada média, sem amostragem de diferenças entre os tipos. | The objectives were to contribute with systematic data about the position of the thymus gland in relation with the skeleton, its topographical and morphometrics parameters and the type, the origin, the number, and the organization of thymic vessels associated in the organ vascularization. It had been used 26 caprins foetus of Saanen breed for macroscopic study that had had their arteries vessels injected with a latex Neoprene 450 solution and 4 foetus for microscopic study of the thymic arteries vascular wall structure. The thoracic and cervical thymic parts showed an own vascularization by direct and indirect branches with the thymic vessels showing a predominant elastic fiber structure on the middle layer without differences between the types.

Estudou-se a disposição e a ramificação das artérias e veias do funículo umbilical de eqüinos sem raça definida, em diferentes fases da prenhez. Utilizou-se para tal trinta fetos, 18 machos e 12 fêmeas com idade variando de 73 a 249 dias, em cujos vasos umbilicais foram injetados solução de látex Neoprene corada e posteriormente dissecados. O comprimento do funículo umbilical variou de 28 a 70 cm (média de 47,5 cm). O funículo umbilical inclui o úraco, duas artérias e uma veia umbilical. Esta última apresentava em média 20,5 cm de comprimento e estava constituida por duas (86,66%) ou três (13,33%) veias tributárias. Notaram-se, ainda, anastomoses arteriovenosas, vasos funiculares, além da vasa vasorum. Anastomoses foram encontradas em 83,33% dos casos, variando de uma a oito e com a seguinte disposição: transversais (57,14%), convergente (9,52%), oblíquas (28,57%), em "H" (2,38%), transversal em "V" (1,19%) e em "X" (1,19%). | The disposition and ramification of the arteries and veins of the umbilical cord from cross-bred equine in different pregnancy stages were studied. Thirty fetuses, 18 male and 12 female with age varying from 73 to 249 days, were used and the umbilical vessels were injected with Neoprene latex 650 colored solution and further dissected. The length of the umbilical cord varied from 28 to 70 centimeters (mean of 47.5 centimeters). The umbilical cord included the urachus, two arteries and one umbilical vein. This latter presented, in average, 20.5 cm in length, and was constituted of two (86.66%) or three (13.33%) tributary veins. Arteriovenous anastomoses, funicular vessels besides the vasa vasorum were also observed. Arteriovenous anastomoses were found in 83.33% of the cases, varying from one to eight, and presented the following disposition: transversal (57.14%), convergent (9.52%), oblique (28.57%), "H"-shaped (2.38%), "V" transversal (1.19%) and "X" transversal (1.19%).

A laparoscopia é uma ferramenta pouco explorada nas técnicas assistidas da reprodução em eqüinos, ao contrário do que já ocorre com o homem, animais de zoológicos e domésticos. Este estudo objetivou verificar a possibilidade de oferecer bases para a canulação do oviduto e sua futura aplicação em programas de transferência de gametas e embriões nesta espécie. Foram realizadas 17 laparoscopias em 10 éguas mantidas em estação onde cada ovário foi abordado pelo flanco ipsolateral. Após identificação da tuba uterina, o infundibulum foi gentilmente tracionado e um cateter avançado em direção ao óstio abdominal da tuba uterina para a ampola, onde foram depositados 250 µl de meio de cultivo (Dulbecco's - PBS). A utilização da técnica laparoscópica em reprodução assistida na égua pode ser considerada pioneira e tem o potencial de diminuir os custos de manutenção de receptoras através do aproveitamento de ciclos repetidos, o que não é possível pela abordagem convencional através de laparotomia. Este custo é um dos principais entraves à aplicação comercial das técnicas assistidas da reprodução em eqüinos. | Laparoscopy is a poorly explored tool for equine assisted reproduction techniques, despite its use in man, zoo and domestic animals. This study had the objective to evaluate the possibility and offer basis for cannulation of the oviduct and its future application in gamete and embryo transfer programs in this species. Seventeen standing laparoscopies were accomplished in ten mares, each ovary approached from its ipsolateral flank. After identification of the uterine tube, the infundibulum was gently tractioned and a catheter advanced in direction of the abdominal ostium of the uterine tube to the ampulla where 250 µL of culture medium (Dulbecco's - PBS) were deposited. The laparoscopic technique associated with assisted reproduction in the mare can be considered pioneer and have the potential of lowering costs with maintenance of receptors by taking advantage of repetitive cycles, which is impossible by means of the conventional approach through laparotomy. This cost is one of the main obstacles for the commercial application of assisted reproduction techniques in horses.

Relata-se neste trabalho o caso de um cão Rottweiler, macho, de três anos de idade, com diagnóstico de osteossarcoma fibroblástico em terço distal de fêmur esquerdo, associado a metástase cutânea. Ressalta-se a insólita ocorrência deste achado em cães, sendo este um fator agravante para o prognóstico desta enfermidade. | This article relates a case of a three-year-old male Rottweiler dog, with diagnostic of fibroblastic osteosarcoma on left femur distal third, associated with cutaneous metastasis. It's detached the rare occurrence of this found in dog, being an aggravating factor for the prognostic of this disease.