Thymic cystic degeneration, pseudoepitheliomatous hyperplasia, and hemorrhage in a dog with brodifacoum toxicosis.

Thymic cysts with pseudoepitheliomatous hyperplasia are described in a 7-month-old female American Eskimo Dog that died of complications from brodifacoum poisoning. Grossly, there was hemothorax with marked cranial mediastinal hemorrhage. Histologically, thymic lobules were expanded and distorted by irregular cysts, lined by single to multiple layers of plump to slightly attenuated polygonal squamous epithelial cells supported by a basement membrane (pseudoepitheliomatous hyperplasia). The thymus had a paucity of lymphocytes and lacked corticomedullary differentiation. Extensive hemorrhage within the cysts and thymic parenchyma extended into the adjacent adipose tissue. To the authors' knowledge, this is the first report of cystic thymic degeneration with pseudoepitheliomatous hyperplasia in a nonhuman species.

Equine placental teratoma.

The placenta from a 300-day-gestational age, female, Arabian equine fetus was examined. Multifocal to coalescing, 0.5- to 4-cm-diameter, white, smooth nodules covered 50% of the placenta. Microscopic evaluation of the nodules revealed undifferentiated germ cells and a haphazard arrangement of immature, mesenchymal stroma, cartilage, squamous cornifying epithelium, scattered ducts and secretory acini lined by cuboidal to columnar epithelium, and mineralized foci. No umbilicus, arrangement about an axial skeleton, or organized polarity of structures was present. The lesion was diagnosed as a placental teratoma, a lesion not reported in species other than man.

Genomic diversity of Bartonella henselae isolates from domestic cats from Japan, the USA and France by pulsed-field gel electrophoresis.

The genomic DNA diversity of 27 Bartonella henselae and three B. clarridgeiae isolates from 18 domestic cats from Japan, the USA and France was investigated by pulsed-field gel electrophoresis (PFGE) with NotI, AscI and SmaI restriction enzymes. A great diversity of genomic patterns was found for all B. henselae, but none for B. clarridgeiae isolates. The DNA size of B. henselae and B. clarridgeiae isolates were 1.7-2.9 and 1.7Mbp, respectively. All 13 Japanese cat isolates were identified as B. henselae type I. Furthermore, three of the four Japanese cats harbored genetically different B. henselae type I isolates, suggesting for the first time co-infection with various type I isolates. One French cat and one American cat were co-infected with B. henselae and B. clarridgeiae. B. henselae type I and type II were mainly grouped in two different clusters by PFGE using SmaI endonuclease in the dendrogram.