History:  A 6-year-old, male German shepherd dog was submitted to the Animal Disease Diagnostic laboratory for necropsy.  Reportedly, the dog had lethargy, diarrhea, vomiting, weight loss, polyuria and polydypsia, and persistent leukopenia.  Reported pertinent clinicopathological data included a CBC consistent with pancytopenia characterized by neutropenia, monocytopenia, lymphopenia, thrombo-cytopenia and anemia, and a bone marrow aspirate revealing marked myeloid hypoplasia and mild erythroid and megakaryocytic hypoplasia.  Per clinical history, the dog was icteric, had elevated liver enzymes (ALT, ALKP and GGT) and a prolonged activated partial thromboplastin time (PPT).

Gross Findings:  The carcass was emaciated, icteric and had multiple petechiae, ecchymotic and/or effusive hemorrhages within the subcutis, diaphragm, intercostal muscles, lungs, liver, mesenteric lymph nodes, kidney, urinary bladder, gastric and intestinal mucosa, and serosa.  The gingival mucosa had multiple ulcers measuring 1.0 x 0.5 cm in greatest dimension.  Pleural and abdominal cavities both contained serosanguinous effusions admixed with fibrin strands.  Fibrinous strands covered serosal surfaces of the diaphragm, lungs, liver, stomach and intestine and caused adherence between the diaphragm and liver and between intestinal loops.  The liver was diffusely yellow-green, diffusely enlarged and friable with multiple perivascular necrotic foci which measured 0.3 cm in greatest dimension and were rimmed by hemorrhage.  Mesenteric lymph nodes were diffusely enlarged, dark-red and bulged on cut surface.  Renal cortices were olive green and papillae had orange discoloration.  Kidneys contained multiple acute and subacute, 0.3 cm in diameter cortical infarcts characterized by wedge-shaped cortical foci which were either red and slightly raised or tan, slightly depressed and rimmed by hemorrhage.  The bone marrow of femur, humerus, several vertebrae and ribs was diffusely yellow and fatty.

Histopathologic findings:  Primary hepatic lesions were multifocal, periportal and centrilobular necrotizing hepatitis and necrotizing vasculitis.  There were numerous intralesional 4-7 µm pseudohyphae and 3-5 µm blastospores.  Necrotic foci with similar intralesional pseudohyphae and blastospores were present within mesenteric lymph nodes.  Renal lesions included multiple septic cortical infarcts characterized by coagulation and liquefactive necrosis, hemorrhage, infiltration with viable and degenerated neutrophils and numerous intralesional small, gram positive, coccoid bacteria.  The hypocellular bone marrow contained primarily adipose connective tissue and hemosiderin-laden macrophages.  There was marked depletion of myeloid precursor cells and mild depletion of erythroid precursor cells and megakaryocytes.

  Enterococcus spp. was isolated from liver, kidney and spleen.  Candida (Torulopsis) glabrata was isolated from liver tissue.

Discussion:  Fibrinous serositis and suppurative-embolic nephritis, together with isolation of Enterococcus spp. from liver, kidney and spleen are diagnostic for Enterococcus spp. septicemia.  Lesions within liver and mesenteric lymph nodes, together with isolation of Candida (Torulopsis) glabrata are consistent with Candida fungemia.  Portal of entry for Enterococcus spp. and Candida glabrata was likely the intestinal tract followed by hematogenous dissemination via the portal vein.  Candida spp. and Enterococcus spp. are opportunistic pathogens, e.g. yeast, fungi, and/or bacteria which live on mucosal surfaces as commensal agents and gain pathogenic properties in the case of immune suppression.  In this case, marked immune suppression was caused by bone marrow aplasia of undetermined etiology.

  Hemorrhagic diathesis and icterus developed likely secondary to septicemia, liver damage, and/or bone marrow suppression. 

  In humans, Enterococcus septicemia and disseminated Candida glabrata infections are serious problems in patients with bone marrow hypoplasia or aplasia, most commonly related to chemotherapy and/or irradiation with cancer therapy, bone marrow transplantation or HIV infection.  Enterococcus spp. are considered as important nosocomial pathogens in human hospitals, particularly because they are already resistant to many antibiotics and have a strong propensity to acquire additional antibiotic resistance determinants.

  Reports about Enterococcus septicemia and Candida fungemia in dogs and cats are rare.  One case of Enterococcus faecalis -associated discospondylitis was reported in a dog.  Multiple antibiotic resistance was found in Enterococcus faecium strains isolated from surgical wounds of hospitalized cats.

  Most Candida spp. isolated from dogs and cats have been identified as Candida albicans.  Affected animals are almost always immune-suppressed due to cytotoxic chemotherapy and/or prolonged glucocorticoid treatment.  Prolonged antibiotic treatment of some affected animals is also reported.

-by Sandra Schoeniger, ADDL Graduate Student