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An intestinal carcinoid with multiple metastases was identified in a 5-year-old male Shih Tzu with a clinical history of anemia, fatigue, anorexia, vomiting, intermittent diarrhea, intestinal bleeding, and progressive emaciation. There was a yellowish-white mass 15 mm in diameter in the anterior jejunum and white nodules consistent with metastases in many organs. Histopathologically, the mass consisted of neoplastic cells arranged in lobules, trabeculae, or closely interdigitating islands of cells. Neoplastic cells were generally polygonal with round hyperchromatic nuclei, modest amounts of eosinophilic cytoplasm, and eosinophilic cytoplasmic granules. Mitoses were common. Rosette formations of tumor cells were apparent in metastatic tumors. Immunohistochemically, tumor cells stained positive for cytokeratin 13, synaptophysin, protein gene product 9.5, neuron-specific enolase, chromogranin A, calcitonin gene-related peptide, serotonin (5-HT), and Leu-7. Serum 5-HT concentrations for this dog were increased 10-fold compared with those of normal dogs. All findings were consistent with a diagnosis of a malignant intestinal carcinoid.

Abstract.A malignant pheochromocytoma with multiple metastases was diagnosed in a 7-year-old male wolfdog that resulted from a cross between an eastern timber wolf (Canis lupus lycaon) and an Alaskan malamute. A yellowish white neoplastic mass approximately 10 cm diameter was found in the right adrenal gland. The neoplasm penetrated through the wall of the caudal vena cava. A diagnosis of pheochromocytoma was established by histopathologic and immunohistochemical procedures. Immunohistochemically, the neoplastic cells expressed chromogranin A, substance P, synaptophysin, Leu-7, protein gene product 9.5, methionine-enkephalin, S100 protein, and galanin. Multiple metastatic tumors were found in the kidneys, spleen, lungs, heart, and liver.Key words: Adrenal gland; immunohistochemistry; neuropeptides; pheochromocytoma; wolfdogs.Pheochromocytoma, an endocrine neoplasm derived from chromaffin cells, is the most common tumor in the adrenal medulla of animals. 2,4,5,17 Pheochromocytomas develop most often in cattle and dogs. 2,4,5 Functional pheochromocytoma has been reported infrequently in animals. 4,5,7 In human medicine, various neuropeptides in addition to epinephrine and norepinephrine have been demonstrated in normal adrenals and pheochromocytomas. 1,9,11,12,14 When metastases are present in nonchromaffin tissues, a pheochromocytoma in humans is considered to be a malignant neoplasm and is frequently nonfunctional. 6 There are only a few reports of malignant pheochromocytomas with multiple metastases have been noted in domestic animals. 2,4 Here, we describe the histopathologic and immunohistochemical characteristics of a pheochromocytoma with multiple metastases.A 7-year-old male wolfdog that resulted from a cross between an eastern timber wolf (Canis lupus lycaon) and an Alaskan Malamute dog developed clinical signs of dysbasia. One month later, the wolfdog developed signs of hyperpnea, emaciation, and vomiting. The clinical course was progressive, and the animal eventually died.Macroscopically, the right adrenal gland was enlarged by a 10-cm-diameter neoplastic mass that was yellowish white and had areas of hemorrhage and necrotic foci on the cut surface. The enlarged adrenal was adhered to adjacent organs, including the right kidney, liver, and caudal vena cava. The neoplasm penetrated through the wall of the caudal vena cava. A thrombus composed of neoplastic cells was present in the caudal vena cava, and the lumen of the vessel was greatly distended caudally. A small pheochromocytoma also was found the left adrenal gland. Multiple white nodular metastases 1-15 mm in diameter were observed in the kidneys, spleen, lungs, and liver. Chronic pulmonary congestion was evident, and in the heart there was right ventricular dilatation and tricuspid insufficiency.Tissue samples from the main visceral organs and the adrenal neoplasm were fixed in 10% formalin, routinely processed, and embedded in paraffin. Histologic sections (4 m) were prepared from paraffin-embedded tissues and stained with hematoxylin and eosin (H...

We demonstrated the experimental vertical transmission of Borna disease virus (BDV) in pregnant BALB/c mice. Giessen strain He/80 of BDV was used in the present study. Six six-week-old mice were inoculated intraperitoneally with 10(5) 50% tissue culture infective doses (TCID50), and were bred immediately. Four pregnant mice were sacrificed under anaesthesia on the 10th and 14th days after vaginal plug formation. Nine newborns from two maternal mice were sacrificed under anaesthesia on the 7th day after birth. Positive signals with RT-nested PCR techniques for BDV p24-RNAs were seen in the fetuses, placentas and brains of all newborn mice. No immunopositivities for BDV p40 were found in the fetuses or placentas at 10 days' gestation. BDV p40 immunopositivities were found in neurons of the fetal brains and in decidual cells of the placentas at 14 days' gestation. They were also found in neurons of the brains of newborn mice. At 10 days' gestation, no positive signals for BDV p40 sense or antisense riboprobes were seen in the fetal brains or placentas. Positive signals were found in neurons of the fetal brains and decidual cells of the placentas at 14 days' gestation. Positive signals for BDV p40 sense and antisense riboprobes were found in almost all neurons throughout the brains of nine newborn mice. These results suggest that persistent infection with BDV in newborn mice may be induced by vertical transmission during gestation.