Bacillary hemoglobinuria in beef cattle infected with Fascioloides magna in Missouri.

Bacillary hemoglobinuria (BH) is an infectious disease, mostly affecting cattle, caused by Clostridium haemolyticum (C. novyi type D), with acute hepatic necrosis and intravascular hemolysis. Cattle are typically predisposed to BH by liver injury caused by Fasciola hepatica, although cases have been reported in cattle without evidence of this parasite. Here we describe a cluster of 14 BH cases from 7 counties in north-central to central Missouri submitted to a veterinary diagnostic laboratory between December 2020 and April 2023. Postmortem examination in all cases revealed hemoglobinuria and acute hepatic necrosis with large numbers of gram-positive bacilli with terminal-to-subterminal spores. Flukes, fluke ova, and/or fluke pigment consistent with Fascioloides magna were identified in 12 of 14 cases. Sequences of the nuclear ribosomal internal transcribed spacer 1 (ITS1) from one fluke had 100% identity to F. magna. C. novyi was detected by fluorescent antibody testing of liver impression smears (11 of 12 cases) and by immunohistochemistry of liver sections (7 of 7 cases). PCR on formalin-fixed, paraffin-embedded tissues amplified the C. haemolyticum beta toxin gene in each of the 7 cases tested. To our knowledge, a confirmed cluster of BH associated with F. magna has not been reported previously in cattle.

Concurrent chronic lymphocytic leukemia and primary hyperparathyroidism in a mule.

A 26-year-old mule gelding was evaluated for chronic weight loss and decreased appetite. The mule had been losing weight and intermittently hypophagic for approximately 7 months. Laboratory analysis of whole blood and plasma identified severe total hypercalcemia, marked hypophosphatemia, markedly increased parathyroid hormone concentration, and marked lymphocytosis. A sestimibi scan intended to identify parathyroid gland tissue was nondiagnostic. Results of flow cytometry and PCR for antigen receptor rearrangement (PARR) were consistent with a B cell lymphoproliferative disorder, likely chronic lymphocytic leukemia (CLL). Although not previously described concurrently, these conditions may sometimes arise together, complicating definition of the underlying mechanism for weight loss and hypercalcemia in aged equids.

Urothelial carcinoma with tonsillar metastasis in a dog.

Given its unusual lymphatic drainage system, the tonsil is a rare site of metastasis, with few reports in the human and veterinary literature. Prognosis in cases of tonsillar metastasis is reportedly poor. We describe here a unique case of urinary bladder urothelial carcinoma (UC) with metastasis to the tonsil in an 11-y-old, spayed female, mixed-breed dog. At presentation, the patient had a history of a growing neck mass and increasing lethargy, hyporexia, weight loss, drooling, and diarrhea for 2 wk. A carcinoma was diagnosed by cytology. Given the poor prognosis, the patient was euthanized. Postmortem examination revealed masses in the inguinal region, cranioventral neck region including tonsil, and urinary bladder. Histologically, the masses were composed of large polyhedral cells arranged in dense sheets and nests with occasional large, clear, intracytoplasmic vacuoles. Neoplastic cells were multifocally positive for uroplakin III and cytokeratin 8/18 by immunohistochemistry. UC with metastasis to tonsil and lymph nodes was diagnosed.

Systemic coccidioidomycosis in a llama cria native to Missouri.

A 3-mo-old male llama was examined because of a 4-wk history of lethargy and ill thrift. Clinical examination revealed subcutaneous masses in the left prescapular and right inguinal regions, mild ataxia, a slight head tilt to the right, and right ear droop. The cria died before clinical workup was complete. At autopsy, there was generalized lymphadenomegaly, a hepatic nodule, a midbrain mass causing rostral compression of the cerebellum, and internal hydrocephalus. Microscopic findings included pyogranulomatous lymphadenitis, meningoencephalitis, hepatitis, and bronchopneumonia. Intralesional fungal spherules, most consistent with Coccidioides spp., were identified in the lymph nodes, lung, and brain. Fungal culture, single-nucleotide variation genotyping real-time PCR, and DNA sequencing confirmed Coccidioides posadasii. The dam of the cria was native to Arizona and had been moved to Missouri ~2.5 y previously. Agar gel immunodiffusion assay of the herd revealed that only the dam was positive for Coccidioides spp.; 6 herdmates were negative. Computed tomography of the dam revealed multiple nodules within the lungs and liver, which were presumed to be an active coccidioidomycosis infection. This case of systemic coccidioidomycosis in a llama native to Missouri was presumably acquired by vertical transmission from the dam.