Five cases of Rhodococcus equi infection in dogs were identified from 2003 to 2014. Three of the dogs had severe, internal lesions attributable to R. equi that have not been previously described: endophthalmitis, endocarditis, and suppurative pleuropneumonia. Isolates from 4 of the dogs were analyzed by polymerase chain reaction for Rhodococcus virulence-associated plasmid (vap) genes. One isolate was vapA-positive, 2 lacked a virulence plasmid, and 1 carried the novel vapN-associated plasmid (pVAPN) recently characterized in bovine isolates. The pVAPN plasmid has not been described in isolates cultured from companion animals. Four of the dogs either were receiving immunosuppressive drugs or had endocrinopathies. R. equi has the potential to cause significant infections in dogs, and immunocompromised animals should be considered at risk for infection.

BackgroundX-linked Alport syndrome (XLAS), caused by mutations in the type IV collagen COL4A5 gene, accounts for approximately 80% of human Alport syndrome. Dogs with XLAS have a similar clinical progression. Prior studies in autosomal recessive Alport mice demonstrated early mesangial cell invasion as the source of laminin 211 in the glomerular basement membrane (GBM), leading to proinflammatory signaling. The objective of this study was to verify this process in XLAS dogs.MethodsXLAS dogs and WT littermates were monitored with serial clinicopathologic data and kidney biopsies. Biopsies were obtained at set milestones defined by the onset of microalbuminuria (MA), overt proteinuria, onset of azotemia, moderate azotemia, and euthanasia. Kidney biopsies were analyzed by histopathology, immunohistochemistry, and electron microscopy.ResultsXLAS dogs showed progressive decrease in renal function and progressive increase in interstitial fibrosis and glomerulosclerosis (based on light microscopy and immunostaining for fibronectin). The only identifiable structural abnormality at the time of microalbuminuria was ultrastructural evidence of mild segmental GBM multilamination, which was more extensive when overt proteinuria developed. Co-localization studies showed that mesangial laminin 211 and integrin α8β1 accumulated in the GBM at the onset of overt proteinuria and coincided with ultrastructural evidence of mild cellular interpositioning, consistent with invasion of the capillary loops by mesangial cell processes.ConclusionIn a large animal model, the induction of mesangial filopodial invasion of the glomerular capillary loop leading to the irregular deposition of laminin 211 is an early initiating event in Alport glomerular pathology.

MicroRNAs (miRNAs) are a group of small noncoding RNAs that act as regulators of posttranslational gene/protein expression and are known to play a key role in physiological and pathological processes. The objective of our study was to compare expression of miR-21 in renal tissue from dogs affected with chronic kidney disease (CKD) caused by X-linked hereditary nephropathy (XLHN), a disease equivalent to human Alport syndrome, to that from unaffected dogs. Additionally, we sought to characterize changes in relative mRNA expression of various genes associated with miR-21 function. miRNA was isolated from kidney tissue collected from both affected dogs and unaffected, age-matched littermates at defined milestones of disease progression, including end-stage renal disease (ESRD). Additionally, autopsy samples from affected dogs at ESRD and corresponding unaffected dogs were evaluated. Samples were scored based on histological changes, and relative expression of miR-21 and kidney disease-related genes was determined using quantitative real-time polymerase chain reaction. In affected dogs, significant upregulation of kidney miR-21 was first detected at the milestone corresponding with increased serum creatinine. Furthermore, miR-21 expression correlated significantly with urine protein: urine creatinine ratio, serum creatinine concentration, glomerular filtration rate, and histologic lesions (glomerular damage, tubular damage, chronic inflammation, and fibrosis). At end-stage disease, COL1A1, TGFB1 and its receptor, TGFB2, and Serpine1 were upregulated, while PPARA, PPARGC1A, ACADM, SOD1, and EGF were downregulated. In conclusion, miR-21 is abnormally upregulated in the kidneys of dogs with CKD caused by XLHN, which may play an important pathologic role in the progression of disease by dysregulating multiple pathways.

Following treatment for pneumonia, a 1-y-old female Nubian goat was presented because of a persistent fever for 3 mo and peripheral lymphadenopathy for 1 mo. Cytology and histology of the superficial cervical and prefemoral lymph nodes demonstrated a moderate-to-marked “left-shifted” lymphoid population, suggestive of lymphoma, and extremely rare extracellular, 2–4 µm, oval, basophilic yeast, consistent with Histoplasma capsulatum. On immunohistochemistry, >95% of the lymphocytes demonstrated positive cytoplasmic and membranous immunoreactivity for CD3. Histoplasma spp. urine antigen and serum antibody testing were positive and negative, respectively. Panfungal PCR and sequencing of DNA extracted from scrolls of formalin-fixed, paraffin-embedded tissue yielded matches to H. capsulatum with 99–100% identity. Given the poor prognosis and persistent pyrexia, the animal was euthanized. Postmortem examination confirmed concurrent multicentric, intermediate-size, T-cell, lymphoblastic lymphoma and histoplasmosis; lesions consistent with intestinal coccidiosis and suspected pulmonary Rhodococcus equi were also noted. Although dimorphic fungi have been described previously in goats, lesions of Histoplasma spp. had not been documented in this species, to our knowledge. Given the low disease burden, it is suspected that the lymphoma was primary, leading to an immunocompromised state and development of secondary, opportunistic infections.

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Neoplasia is usually encountered in the African pygmy hedgehog at a mean age of 3.5 y, and malignancy is common. Myelogenous leukemias are rarely reported in hedgehogs. We describe 3 cases of eosinophilic leukemia in adult, middle-aged (mean age: 2.3 y) hedgehogs, for which prognosis appears grave. In 1 case, attempted treatment was unsuccessful, and in all 3 cases, the disease course was rapid and all died soon after diagnosis. Blood smear evaluation, along with complete blood count, was critical in making the diagnosis in all cases. Luna stain was validated and used to better visualize eosinophils in cytologic and histologic sections. Electron microscopy confirmed the presence of specific granules in hedgehog eosinophils.

A 2-year-old female spayed Boxer dog was presented to the Texas A&M University Veterinary Medical Teaching Hospital for further investigation of chronic hemorrhagic diarrhea of 6 weeks duration and significant weight loss despite previous administration of antibiotics (oxytetracycline, sulfadimethoxine/ormetoprim and metronidazole), a single dose of steroids (dexamethasone), a vitamin B12 injection, maropitant, fluid therapy, and prescription diet trials. Complete blood counts and fecal flotations performed by the referring veterinarian were unremarkable. The dog resided in a multi-dog household and was primarily indoors with access to large areas of agricultural land with livestock and stagnant water bodies. All other dogs in the household were apparently healthy. Physical examination revealed a 3/9 body condition score and a thickened colonic wall on digital rectal examination. A sinus Abstract A 2-year-old female spayed Boxer dog was presented for a 1-month history of progressive hemorrhagic diarrhea with tenesmus and weight loss despite trial courses of antibiotics and diet change. Abdominal ultrasound revealed severe, focal thickening, and loss of normal architecture of the colonic wall with abdominal lymphadenomegaly. Dry-mount fecal cytology, performed on several consecutive days, consistently revealed numerous, round, 16-20 μm structures with basophilic, granular content, and a thin cell wall. Transmission electron microscopy identified these structures as fungi. Culture, polymerase chain reaction (PCR), and sequencing of the internal transcribed spacer, D1/D2 regions, and DNA-directed RNA polymerase II core subunit (RPB2) confirmed the presence of Basidiobolus microsporus in the feces. Biopsies collected via ileocolonoscopy revealed marked, multifocal, chronic, neutrophilic, and eosinophilic ileitis and colitis with ulceration, granulation tissue, and intralesional hyphae (identified with Gomori methenamine silver stain). A Pythium enzyme-linked immunosorbent assay and Pythium-specific PCR performed on the formalin-fixed paraffin-embedded biopsy specimens were positive while Basidiobolus-specific PCR was negative, thus confirming a diagnosis of pythiosis. This report describes a fatal case of colonic and intestinal pythiosis infection with the presence of fecal Basidiobolus sp. spores, suggestive of concurrent gastrointestinal basidiobolomycosis infection. K E Y W O R D S canine, diarrhea, oomycosis, zygomycosis

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