Characterization of a Vesivirus Associated with an Outbreak of Acute Hemorrhagic Gastroenteritis in Domestic Dogs.

Four of eleven affected dogs died despite aggressive treatment during a 2015 focal outbreak of hemorrhagic gastroenteritis following a stay in a pet housing facility. Routine diagnostic investigations failed to identify a specific cause. Virus isolation from fresh necropsy tissues yielded a calicivirus with sequence homology to a vesivirus within the group colloquially known as the vesivirus 2117 strains that were originally identified as contaminants in CHO cell bioreactors. In situ hybridization and reverse transcription-PCR assays of tissues from the four deceased dogs confirmed the presence of canine vesivirus (CaVV) nucleic acids that localized to endothelial cells of arterial and capillary blood vessels. CaVV nucleic acid corresponded to areas of necrosis and hemorrhage primarily in the intestinal tract, but also in the brain of one dog with nonsuppurative meningoencephalitis. This is the first report of an atypical disease association with a putative hypervirulent vesivirus strain in dogs, as all other known strains of CaVV appear to cause nonclinical infections or relatively mild disease. After identification of the CU-296 vesivirus strain from this outbreak, four additional CaVV strains were amplified from unrelated fecal specimens and archived stocks provided by other laboratories. Broader questions include the origins, reservoir(s), and potential for reemergence and spread of these related CaVVs.

Zinc Toxicosis in a Boxer Dog Secondary to Ingestion of Holiday Garland.

INTRODUCTION: Increased admissions occur in small animal veterinary emergency clinics during some holidays, and some of the increased caseload is due to ingestion of toxic substances. This report documents zinc toxicosis contributing to the death of a dog after ingestion of holiday tinsel garland. CASE STUDY: A mature boxer dog presented with a 4-day history of vomiting and diarrhea. Radiodense foreign material was detected in the stomach and removed via gastrotomy. The patient clinically worsened over the next several days with evidence of hemolytic anemia, severe hypernatremia, and an elevated WBC count with a suspected dehiscence of the surgical site and acute renal failure. The serum zinc concentration was moderately elevated. Postmortem findings included surgical dehiscence from the gastrotomy and enterotomy sites, hepatic extramedullary hematopoiesis, hemoglobinuric nephrosis, and pancreatic fibrosis. The foreign material removed from the stomach also contained zinc. DISCUSSION: Ingestion of holiday tinsel garland made from metal-coated plastic film has not previously been implicated in zinc toxicosis. Zinc toxicosis has a good prognosis in veterinary medicine when diagnosed and treated promptly, but the unique source of zinc in this dog contributed to the delay in diagnosis and grave outcome in this case.

Blood smear from a pregnant cat that died shortly after partial abortion.

A 1-year-old, 5- to 6-week pregnant cat was presented with a history of aborting 3 kittens the previous night. During the examination, the cat began to seizure and died. At necropsy, formalin-fixed tissues and blood smears prepared from an EDTA blood sample collected via cardiac puncture were submitted to a diagnostic laboratory. Examination of the blood smears revealed numerous large (15-75 microm) clumped macrophages containing dark blue intracytoplasmic organisms consistent with Cytauxzoon merozoites. Scattered erythrophagocytic macrophages were also observed. Within several erythrocytes, 1-2 small, round, ring-like piroplasms consistent with Cytauxzoon were observed. Histologic examination revealed numerous large, schizont-laden macrophages filling the blood vessels of multiple organs. The cytologic and histologic findings were diagnostic for Cytaxuzoon felis infection. This case was of particular interest because of the unusually large number of organism-laden macrophages in the cardiac blood sample, an uncommon finding in peripheral blood. Although the cat was presented for complications of abortion, it remains uncertain whether C felis organisms crossed the placenta and infected the fetuses or lead to the abortions.