Mycobacterium microti: Not Just a Coincidental Pathogen for Cats.

Public interest in animal tuberculosis is mainly focused on prevention and eradication of bovine tuberculosis in cattle and wildlife. In cattle, immunodiagnostic tests such as the tuberculin skin test or the interferon gamma (IFN-γ) assay have been established and are commercially available. Feline tuberculosis is rather unknown, and the available diagnostic tools are limited. However, infections with Mycobacterium tuberculosis complex members need to be considered an aetiological differential diagnosis in cats with granulomatous lymphadenopathy or skin nodules and, due to the zoonotic potential, a time-efficient and accurate diagnostic approach is required. The present study describes 11 independent cases of Mycobacterium microti infection in domestic cats in Switzerland. For three cases, clinical presentation, diagnostic imaging, bacteriological results, immunodiagnostic testing, and pathological features are reported. An adapted feline IFN-γ release assay was successfully applied in two cases and appears to be a promising tool for the ante mortem diagnosis of tuberculosis in cats. Direct contact with M. microti reservoir hosts was suspected to be the origin of infection in all three cases. However, there was no evidence of M. microti infection in 346 trapped wild mice from a presumptive endemic region. Therefore, the source and modalities of infection in cats in Switzerland remain to be further elucidated.

Evaluation of a novel non-surgical post-pyloric feeding technique in dogs with severe acute kidney injury.

OBJECTIVES: To evaluate the placement and the performance of a new post-pyloric feeding (PPF) system, and compare it to esophageal (E) feeding in dogs with severe acute kidney injury (AKI). DESIGN: Prospective study. SETTING: University teaching hospital. ANIMALS: Twenty client-owned dogs with severe AKI treated with hemodialysis. INTERVENTIONS: Dogs were randomly assigned to 2 feeding techniques, PPF or E feeding; for PPF, an 8-Fr jejunal (J) tube was introduced through a standard 18-Fr E-tube and advanced endoscopically through the pylorus. A commercial liquid diet was administered at a continuous rate for at least 5 days. After the removal of the internal J-tube, feeding was continued through the E-tube. Control dogs were fed blended food 5 times daily through an E-tube. Placement technique, nutritional efficiency, and metabolic response to nutritional support were compared between the groups. MEASUREMENTS AND MAIN RESULTS: Feeding tubes were placed a medium of 1 day (interquartile range, 0.8 d) after presentation. Median procedure-time in the group PPF was 26.5 min (11.5 min), including 8.5 min (2.7 min) for the E-tube and 17.5 min (5.0 min) for the J-tube. J-tubes were used for 5 days (1.5 d) with oral displacement observed in 3/10 dogs. The goal to administer 130% resting energy requirement within 3 days was reached in 13/20 dogs (8/10 PPF, 5/10 E). Despite nutritional support, dogs lost 1.2% body weight per day (1.1%), with no difference between the groups. The metabolic improvement was comparable between the groups, despite marked differences in the diet composition. CONCLUSIONS: This new feeding technique can be recommended as an efficient method for early nutritional support in dogs with severe AKI. The protein-energy wasting observed despite active nutritional support suggests, however, the necessity for increased feeding targets or qualitative changes in diet composition for dogs with AKI.

Characterization of the inflammatory infiltrate and cytokine expression in the skin of horses with recurrent urticaria.

BACKGROUND: Recurrent urticaria (RU) is a common skin disease of horses, but little is known about its pathogenesis. HYPOTHESIS/OBJECTIVE: The aim of this study was to characterize the inflammatory cell infiltrate and cytokine expression pattern in the skin of horses with RU. ANIMALS: Biopsies of lesional and nonlesional skin of horses with RU (n = 8) and of skin from healthy control horses (n = 8) were evaluated. METHODS: The inflammatory cell infiltrate was analysed by routine histology. Immunohistochemistry was used to identify T cells (CD3), B ells (CD79), macrophages (MAC387) and mast cells (tryptase). Expression of T-helper 2 cytokines (interleukins IL-4, IL-5 and IL-13), a T-helper 1 cytokine (interferon-γ), IL-4 receptor α and thymic stromal lymphopoietin was assessed by quantitative RT-PCR. Results - In subepidermal lesional skin of RU-affected horses, increased numbers of eosinophils (P ≤ 0.01), CD79-positive (P ≤ 0.01), MAC387-positive (P ≤ 0.01) and tryptase-positive cells (P ≤ 0.05) were found compared with healthy horses. Subepidermal lesional skin of RU-affected horses contained more eosinophils (P ≤ 0.05) and tryptase-positive cells (P ≤ 0.05) compared with nonlesional skin. There was no significant difference in infiltrating cells between nonlesional skin and skin of healthy horses. Expression of IL-4 (P ≤ 0.01), IL-13 (P ≤ 0.05), thymic stromal lymphopoietin (P ≤ 0.05) and IL-4 receptor α (P ≤ 0.05) was increased in lesional skin of RU-affected horses compared with control horses. Expression of IL-4 was higher (P ≤ 0.05) in lesional compared with nonlesional RU skin. CONCLUSIONS AND CLINICAL IMPORTANCE: Analysis of cytokine expression and inflammatory infiltrate suggests that T-helper 2 cytokines, eosinophils, mast cells and presumptive macrophages play a role in the pathogenesis of equine RU.