Granulomatous Rhinitis in a Horse due to Mycobacterium intracellulare Infection.

Mycobacterial infections in horses are uncommon, but are caused most frequently by Mycobacterium bovis of the Mycobacterium tuberculosis complex or Mycobacterium avium of the M. avium complex. Disease caused by Mycobacterium intracellulare, the second most common species within the M. avium complex, has not been reported in horses to date. Mycobacteriosis in horses most often presents as enteric, pulmonary or, rarely, systemic disease. Here we report a case of M. intracellulare infection in a horse presenting as a granulomatous nasal mass.

Protein biomarker of cell proliferation determines survival to discharge in cases of equine large colon volvulus.

BACKGROUND: Progenitor cells play critical roles in epithelial repair following ischaemic injury. Protein biomarkers have been used to identify intestinal progenitor cell subpopulations. This study aims to determine if a critical number of intestinal progenitor cells can predict tissue viability and survival to discharge of large colon volvulus (LCV) cases. OBJECTIVES: The objectives were to 1) identify intestinal progenitor cell subpopulations using biomarkers: proliferating cell nuclear antigen (PCNA), sex determining region Y box 9 (SOX9), phospho-histone H3 (PHH3) and Ki-67, 2) define cut-off values for critical numbers of positive cells and 3) determine if survival to discharge is associated with cut-off values. STUDY DESIGN: Retrospective cohort study. METHODS: Adult horses admitted to the Farm and Equine Veterinary Medical Center at NC State's Veterinary Hospital and Peterson and Smith Equine Hospital between 2006 and 2016 that underwent an exploratory coeliotomy with a diagnosis of LCV of ≥360 degrees, had pelvic flexure biopsy and that recovered from general anaesthesia were selected for inclusion in the study. Immunohistochemical analyses were performed and positive cells were counted. Optimal cut-off values were determined using receiver operator curves. A Fisher's exact test was used to associate cut-off values with survival to discharge. RESULTS: In this study, 23 cases of LCV ≥360° were included. Of 23 horses, 13 (57%) survived to discharge. A cut-off value of <2.1 PHH3 positive cells per crypt correctly predicted death with 100% sensitivity (95% CI; 69.15-100%) and 84.62% specificity (95% CI; 54.55-98.08%). LCV cases with <2.1 PHH3 positive cells per crypt were 96.6 times more likely to die (95% CI; 4.14-2255 and P < 0.0001). Biomarkers PCNA, SOX9 and Ki-67 did not predict short-term survival. MAIN LIMITATIONS: The population size was small. CONCLUSIONS: PHH3 immunohistochemical analysis may assist in more accurate prediction of survival to hospital discharge of LCV cases. The summary is available in Spanish - see Supporting Information.

Comparative pathology of canine soft tissue sarcomas: possible models of human non-rhabdomyosarcoma soft tissue sarcomas.

Comparative analyses of canine and human soft tissue sarcomas (STSs) are lacking. This study compared the histological and immunohistochemical (labelling for desmin, smooth muscle actin [SMA], CD31, pancytokeratin, S100 and CD34) appearance of 32 archived, formalin-fixed, paraffin wax-embedded canine STS tumour specimens by board-certified veterinary and medical pathologists, both blinded to the other's interpretations. Comparison between the veterinary and human diagnoses revealed a generally consistent pattern of interpretation with few notable variations. Most tumours (13/32) were judged to display similar histomorphological appearance to human low-grade spindle cell sarcomas, appearing non-distinctive and morphologically of a fibroblastic/myofibroblastic type. Five canine cases resembled human liposarcoma, but with atypical desmin-positive epithelioid cells present. Five canine cases resembled human spindle cell sarcoma with myxoid features and two additional cases resembled human myxofibrosarcoma. Seven canine cases were noted to resemble human undifferentiated sarcoma. Findings in the present study demonstrate that canine STSs display histological and immunohistochemical features similar to their human equivalents. Because of these cross-species similarities, a particular opportunity exists to understand the biology and treatment of human STS by potentially including dogs as clinical models.