Resumen: En el presente trabajo se describen los hallazgos macroscópicos y microscópicos de un mesotelioma pleural en un canino, ovejero alemán, macho, de 6 años que presentaba disnea y pérdida de peso por 20 días. El animal fue ingresado al Hospital Veterinario de la Facultad de Veterinaria de la Udelar, se descompensó y falleció durante la consulta. El cadáver fue remitido a la Unidad de Patología para su estudio post-mortem. La necropsia reveló hemoperitoneo, hepatomegalia, hemotórax abundante; se evidenció una gran masa en el mediastino, de forma irregular, que se extendía por toda la cavidad, adherida a la pleura parietal y a la parrilla costal; dicha masa estaba formada por multinodulaciones de pocos milímetros de diámetro y coloración blanquecina, de consistencia friable. Además, se observó hemopericardio, se constató infiltración de diafragma, pericardio y epicardio. En el examen histopatológico de la masa y del tejido cardíaco se identificaron células mesoteliales de gran tamaño, con forma cuboidal o poliédrica, agrupadas conformando estructuras arborizantes con una discreta cantidad de estroma conectivo. Las células presentaban citoplasma claro con vacuolas, núcleo grande e intensamente basófilo y algunas binucleadas, con nucléolo prominente, mostraban pocas mitosis y marcada anisocariosis y anisocitosis, se diagnosticaron como un mesotelioma de tipo papilar. Este diagnóstico se confirmó mediante inmunohistoquímica, se observó inmunomarcación positiva a vimentina y pancitoqueratina en las células tumorales.

Summary: This work describes macroscopic and microscopic findings of pleural mesothelioma in a 6-y.o., male German shepherd dog with dyspnea and weight loss for 20 days. The animal was admitted to the Veterinary Hospital of Facultad de Veterinaria Udelar, and collapsed and died during the consultation. The body was referred to the Pathology Unit for post-mortem examination. The necropsy revealed hemoperitoneum, hepatomegaly, abundant hemothorax, a large irregular mass in the mediastinum extending throughout the cavity, adhered to the parietal pleura and rib cage; was formed by multinodulations of few millimeters in diameter and whitish coloration, with friable consistency. In addition, hemopericardium, infiltration of the diaphragm, pericardium, and epicardium was observed. Histopathological examination of the mass and cardiac tissue identified large cuboidal to polyhedral mesothelial cells, grouped in arborizing structures with a discrete amount of connective stroma. The cells had clear cytoplasm with vacuoles, large and intensely basophilic nuclei and some of them binucleated, with prominent nucleolus, few mitoses, and marked anisokaryosis and anisocytosis, diagnosing as a papillary mesothelioma. The confirmatory diagnosis was carried out by immunohistochemistry, showing positive immunolabeling for vimentin and pan-cytokeratin in the tumor cells.

Resumo: Este trabalho descreve os achados macroscópicos e microscópicos de um mesotelioma pleural num canino pastor alemão macho de 6 anos de idade que apresentava dispneia e perda de peso há 20 dias. O animal foi internado no Hospital Veterinário da Faculdade de Veterinária de Udelar, descompensou e morreu durante a consulta. A carcaça foi enviada para a Unidade de Patologia para exame post-mortem. A necropsia revelou hemoperitoneu, hepatomegalia, hemotórax abundante, uma grande massa irregular no mediastino que se estendia por toda a cavidade, aderida à pleura parietal e à grelha costal; esta massa era formada por multinodulações de alguns milímetros de diâmetro e de cor esbranquiçada, com uma consistência friável. Para além disso, observou-se hemopericárdio, infiltração do diafragma, do pericárdio e do epicárdio. O exame histopatológico da massa e do tecido cardíaco revelou células mesoteliais grandes, cuboidais ou poliédricas, agrupadas em estruturas arborizadas com uma quantidade discreta de estroma conjuntivo. As células apresentavam citoplasma claro com vacúolos, núcleos grandes e intensamente basófilos e alguns binucleados, com nucléolos proeminentes, poucas mitoses e marcada anisocariose e anisocitose, tendo sido diagnosticado como mesotelioma papilar. Este diagnóstico foi confirmado por imunohistoquímica, mostrando imunomarcação positiva para vimentina e pancitoqueratina nas células tumorais.

ABSTRACT The objective of this study was to determine the impact of metabolic changes occurring in induced subclinical gestation toxaemia in ewes on metabolic parameters and vigour in the first 72 h of their lambs’ life. Fifty-one adult Corriedale ewes of known gestation date and fed on a natural pasture were randomly divided into four groups at day 145 of gestation. Group A (ewes with single pregnancies) and group C (ewes with twin pregnancies) were fed on a natural pasture throughout the trial; group B (ewes with single pregnancies) and group D (ewes with twin pregnancies) were subjected to 75% feed restriction for three days until they reached glycaemia and β-hydroxybutyrate (BHB) values indicative of subclinical gestational toxaemia. The birth-to-first station and birth-to-first suckling times of the born lambs were studied. Within the first hour after parturition and at 24, 48, and 72 h, glycaemia and BHB concentrations were determined in the blood of lambs, and body temperature and body weight were assessed at the same time. Relative weight gain at 72 h of age was calculated for all lambs. The BHB concentration determined at all times studied showed no difference among the groups. Subclinical gestation toxaemia induced in ewes subjected to feed restriction causes a decrease in the glycaemia of their lambs in the first hour of life; however, it does not cause an increase in ketone bodies. The metabolic changes induced in the mothers do not have negative effects on the vigour of the lambs at birth, as the weight, temperature, and the time it took for lambs to stand and suckle are not affected. However, they have a negative effect on relative weight gain in the critical period of the first 72 h of life. 7 life Fiftyone Fifty one 14 pregnancies trial 75 βhydroxybutyrate β hydroxybutyrate (BHB birthtofirst birth 24 48 however bodies affected However 1 2 4

ABSTRACT The objective of this work was to determine the repercussion of the metabolic changes that occur in induced subclinical pregnancy toxemia in single- or twin-bearing ewes on the duration of gestation, type and length of lambing, and placental expulsion time. Fifty-one adult Corriedale ewes with a known gestation date and fed in the wild were randomly divided at day 145 of gestation into four groups. Group A included single-bearing ewes, and C twin-bearing ewes, all of which were fed ad libitum . Group B was composed of single-bearing ewes, and D of twin-bearing ewes, all subjected to a 75% feed restriction until glycemic values were compatible with subclinical pregnancy toxemia. Metabolic parameters were determined in all ewes from day 145 of gestation to 72 h postpartum. Likewise, the duration of gestation, type of lambing (eutocic/dystocic), labor length, and placental expulsion time were recorded. Glycemia and β-hydroxybutyrate values compatible with subclinical pregnancy toxemia were achieved after 48 h of feed restriction, being 30.67±2.37 mg/dL and 1.87±0.12 mmol/L in single-bearing ewes and 28.40±3.39 mg/dL and 2.21±0.42 mmol/L in twin-bearing ewes, respectively. It is concluded that subclinical pregnancy toxemia induced by feed restriction at the end of gestation, frequent situation that occurs in flock management, produces mild metabolic changes, which return to normal values after the delivery. These metabolic changes registered before lambing do not modify the gestation length, do not increase the percentage of dystocical deliveries, nor influence labor length or placental expulsion time.