Obstructive cardiac myxosarcoma of the right ventricular outflow tract with pulmonary embolism and concurrent right atrial hemangiosarcoma in a dog.

A 13-year-old spayed female rottweiler crossbreed dog was presented with an 8-day history of abnormal gait and collapse associated with excitement or physical activity. A cardiac gallop was noticed on thoracic auscultation, and a 1st-degree atrioventricular block and sinus tachycardia were noted on an electrocardiogram. Echocardiography identified a hypoechoic, irregularly marginated luminal mass in the right ventricle at the level of the pulmonic valves. Postmortem gross examination confirmed the presence of a soft, polypoid, and botryoid mass (9 × 3 × 3 cm) with a smooth and glistening surface attached to the endocardium of the right ventricular outflow tract and extending to the pulmonary artery. The histological findings were consistent with the diagnosis of myxosarcoma with pulmonary embolism. In addition, the dog in this report had a right atrial hemangiosarcoma and a cutaneous hemangioma unrelated to her clinical findings. Key clinical message: Cardiac myxosarcomas are very rare neoplasms in dogs and concomitant primary heart tumors of different histogenesis are even rarer in dogs. To the authors' knowledge, this is the first report of coexistent myxosarcoma and hemangiosarcoma in the heart of a dog. Cardiac myxosarcomas should be considered in the differential diagnosis of intracavitary heart masses associated with signs of cardiac obstruction and failure.

Myxosarcome cardiaque obstructif de la voie d'éjection du ventricule droit avec embolie pulmonaire et hémangiosarcome auriculaire droit concomitant chez un chien. Une chienne croisée rottweiler stérilisée âgée de 13 ans a été présentée avec une histoire de démarche anormale et d'effondrement associés à l'excitation ou à l'activité physique depuis 8 jours. Un galop cardiaque a été noté à l'auscultation thoracique, un bloc auriculo-ventriculaire du 1er degré et une tachycardie sinusale ont été notés à l'électrocardiogramme. L'échocardiographie a permis d'identifier une masse luminale hypoéchogène et irrégulièrement marginalisée dans le ventricule droit au niveau des valvules pulmonaires. L'examen macroscopique post-mortem a confirmé la présence d'une masse molle, polypoïde et botryoïde (9 × 3 × 3 cm) avec une surface lisse et brillante attachée à l'endocarde de la voie d'éjection du ventricule droit et s'étendant jusqu'à l'artère pulmonaire. Les résultats histologiques concordaient avec le diagnostic de myxosarcome avec embolie pulmonaire. De plus, la chienne dans ce rapport présentait un hémangiosarcome auriculaire droit et un hémangiome cutané sans rapport avec ses résultats cliniques.Message clinique clé :Les myxosarcomes cardiaques sont des néoplasmes très rares chez le chien et les tumeurs cardiaques primaires concomitantes d'histogenèse différente sont encore plus rares chez le chien. À la connaissance des auteurs, il s'agit du premier rapport de myxosarcome et d'hémangiosarcome coexistant dans le cœur d'un chien. Les myxosarcomes cardiaques doivent être pris en compte dans le diagnostic différentiel des masses cardiaques intracavitaires associées à des signes d'obstruction et d'insuffisance cardiaque.(Traduit par Dr Serge Messier).

Right atrioventricular valve dysplasia in a meerkat.

A 7-y-old, captive, intact female meerkat (Suricata suricatta) was presented with lethargy, decreased appetite, dyspnea, and distended abdomen. At autopsy, the right atrium was markedly dilated, and the right atrioventricular valve (RAV) was dysplastic with shortened or absent chordae tendineae and direct attachment of the valve to the papillary muscles, which, in turn, were fused and abnormally positioned. The right ventricle was considered to be hypertrophied. Also present were hydrothorax, ascites, atelectasis, and hepatic congestion. A diagnosis of RAV dysplasia was made. Histologic findings included hypertrophy of cardiomyocytes and marked centrilobular hepatic congestion and hemorrhage, which were consistent with right-sided heart failure.

Mineralized, obstructive cardiac myxoma with chondroid differentiation in a cocker spaniel.

A 12-year-old castrated male cocker spaniel dog was referred for evaluation of signs consistent with right-sided heart failure. Thoracic radiography revealed mineralization in the region of the right atrium. Echocardiography identified a mass partially filling the right atrium and right ventricle and obstructing flow through the right heart. These findings were confirmed at necropsy and histopathologic features were consistent with myxoma with chondroid differentiation.

Myxome cardiaque obstructif minéralisé avec différenciation chondroïde chez un cocker. Un chien cocker mâle castré de 12 ans a été référé pour une évaluation de signes compatibles avec une insuffisance cardiaque droite. La radiographie thoracique a révélé une minéralisation dans la région de l'oreillette droite. L'échocardiographie a identifié une masse remplissant partiellement l'oreillette droite et le ventricule droit et obstruant le flux à travers le cæur droit. Ces résultats ont été confirmés à l'autopsie et les caractéristiques histopathologiques étaient compatibles avec un myxome à différenciation chondroïde.(Traduit par Dr Serge Messier).

EUCOLEUS BOEHMI INFECTION IN THE NASAL CONCHAE AND PARANASAL SINUSES OF RED FOX (VULPES VULPES) ON PRINCE EDWARD ISLAND, CANADA.

Eucoleus boehmi (Nematoda: Capillariidae) occurs in the nasal conchae and paranasal sinuses of wild and domestic canids. We surveyed the red fox ( Vulpes vulpes ) on Prince Edward Island, Canada, for E. boehmi infection and characterized the associated histopathology. Nasal capillarid infections were detected based on histologic examination of three coronal sections of the nasal cavity and by centrifugal flotation examination (CFE) of rectal feces. Capillarids were detected in histologic sections in 28 of 36 (78%) foxes; detection occurred most frequently in the caudal section (28 foxes) and least in the rostral section (10 foxes). Adult worm morphology was typical for capillarids (stichosome esophagus, bacillary bands, bipolar plugged eggs); E. boehmi eggs were specifically identified based on the characteristic pitted shell wall surface. Adult worms were detected in histologic sections in all 28 and E. boehmi eggs in 21 of the positive foxes. No eggs of Eucoleus aerophilus were observed in any of the sections. Affected foxes had an eosinophilic and lymphoplasmacytic rhinitis with goblet cell hyperplasia. Eggs of E. aerophilus were detected on CFE in 20 of 36 (56%) foxes; 19 of the histologically positive foxes were coinfected with E. aerophilus. Eggs of E. boehmi were detected on CFE in 26 of 36 (72%) foxes and were consistent in size and morphology with those described from wild canids, but they differed from those reported from cases of infection in dogs. Prevalence based on identification of eggs on histologic section or CFE indicated 27 of 36 (75%) red foxes examined were infected with E. boehmi.

Evaluation of an in vivo heterotopic model of osteogenic differentiation of equine bone marrow and muscle mesenchymal stem cells in fibrin glue scaffold.

Autologous mesenchymal stem cells (MSCs) have been used as a potential cell-based therapy in various animal and human diseases. Their differentiation capacity makes them useful as a novel strategy in the treatment of tissue injury in which the healing process is compromised or delayed. In horses, bone healing is slow, taking a minimum of 6-12 months. The osteogenic capacity of equine bone marrow and muscle MSCs mixed with fibrin glue or phosphate-buffered saline (PBS) as a scaffold is assessed. Bone production by the following groups was compared: Group 1, bone marrow (BM) MSCs in fibrin glue; Group 2, muscle (M) MSCs in fibrin glue; Group 3, BM MSCs in PBS; Group 4, M MSCs in PBS and as a control; Group 5, fibrin glue without cells. BM and M MSCs underwent osteogenic stimulation for 48 h prior to being injected intramuscularly into nude mice. After 4 weeks, the mice were killed and muscle samples were collected and evaluated for bone formation and mineralization by using radiology, histochemistry and immunohistochemistry. Positive bone formation and mineralization were confirmed in Group 1 in nude mice based on calcium deposition and the presence of osteocalcin and collagen type I; in addition, a radiopaque area was observed on radiographs. However, no evidence of mineralization or bone formation was observed in Groups 2-5. In this animal model, equine BM MSCs mixed with fibrin glue showed better osteogenic differentiation capacity compared with BM MSCs in PBS and M MSCs in either carrier.

Pig heart preservation with antegrade intracellular crystalloid versus antegrade/retrograde miniplegia.

Both histidine-tryptophan-ketoglutarate (HTK) solution and Braile miniplegia are commercially available and used with high success. The objective of this work was to compare the effects of both strategies in an animal model. Twelve pigs were divided into control, HTK, or Braile groups using a model of controlled global cardiac ischemia/reperfusion under cardiopulmonary bypass with 1 hour heart ischemia followed by 2 hour reperfusion. No significant differences were found over time or between groups for heart rate, arrhythmia, number of defibrillations required, blood gases, myocardial lactate production, myocardial oxygen consumption, nor coronary flow index. The Braile strategy was associated with a lower 120 minute postreperfusion coronary vascular resistance with higher water content, leukocyte infiltration, and oxidative damage compared with controls. Drainage of HTK solution to the venous return was followed by higher potassium and lower sodium blood concentrations. One-hour heart preservation with HTK or Braile systems followed by 2 hour reperfusion both allow for acceptable preservation of the healthy pig myocardium. Maneuvers such as leukocyte filtration or hemofiltration may further improve these conditions.

Animal models of copper-associated liver disease.

Recent advances in molecular biology have made possible the identification of genetic defects responsible for Wilson's disease, Indian childhood cirrhosis and copper toxicosis in Long Evans Cinnamon rats, toxic milk mice, and Bedlington terriers. The Wilson's disease gene is localized on human chromosome 13 and codes for ATP7B, a copper transporting P-type ATPase. A genetic defect similar to that of Wilson's disease occurs in Long Evans Cinnamon rats and toxic milk mice. Familial copper storage disorders in Bedlington and West Highland white terriers are associated with early subclinical disease, and copper accumulation with subsequent liver injury culminating in cirrhosis. The canine copper toxicosis locus in Bedlington terriers has been mapped to canine chromosome region CFA 10q26. Recently, a mutated MURR1 gene was discovered in Bedlington terriers affected with the disease. Idiopathic childhood cirrhosis is biochemically similar to copper toxicosis in Bedlington terriers, but clinically much more severe. Both conditions are characterized by the absence of neurologic damage and Kayser-Fleisher rings, and normal ceruloplasmin levels. A recent study added North Ronaldsay sheep to the list of promising animal models to study Indian childhood cirrhosis. Morphologic similarities between the two conditions include periportal to panlobular copper retention and liver changes varying from active hepatitis to panlobular pericellular fibrosis, and cirrhosis. Certain copper-associated disorders, such as chronic active hepatitis in Doberman pinschers and Skye terrier hepatitis are characterized by copper retention secondary to the underlying disease, thus resembling primary biliary cirrhosis in humans. Copper-associated liver disease has increasingly being recognized in Dalmatians. Copper-associated liver diseases in Dalmatians and Long Evans Cinnamom rats share many morphologic features. Fulminant hepatic failure in Dalmatians is characterized by high serum activities of alanine aminotransferase and aspartate aminotransferase, and severe necrosis of centrilobular areas (periacinar, zone 3) hepatocytes. Macrophages and surviving hepatocytes contain copper-positive material. Liver disease associated with periacinar copper accumulation has also been described in Siamese cats. Many questions regarding copper metabolism in mammals, genetic background, pathogenesis and treatment of copper-associated liver diseases remain to be answered. This review describes the similarities between the clinico-pathological features of spontaneous copper-associated diseases in humans and domestic animals.