Pythiosis cutaneous in horses treated with triamcinolone acetonide. Part 3. Histomorphometric analysis

Objective. The objective of the study was to analyze Histomorphometrically of the healing process with cutaneous pythiosis in horses treated with triamcinolone acetonide. Materials and methods. 24 horses with pythiosis were used, to a group 50 mg of intramuscular triamcinolone acetonide (GT) was applied, while the other group was not applied treatment (GC). They were collected tissue biopsies, processed, sliced and stained with hematoxylin and eosin (H & E), Gomori trichrome (TG), picrosirius red / polarization (PR / P) and Grocott methenamine silver (GMS). Photomicrographs were selected and 10 histological changes, analyzed with BioEstat 5.0 software, obtaining quantities of tissue cells such as eosinophils, neutrophils, macrophages, fibroblasts and collagen through planimetric evaluation point count. Results. In GSM staining was observed decrease in the presence of intralesional hyphae of P. insidiosum to 16 days (p<0.05). Staining H&E, we observed a decrease of the inflammatory process, shown in eosinophils (p=0.0001), neutrophils (p=0.0001), and macrophage (p=0.00001). In the staining of GT and PR/P increase the amount of fibroblasts and collagen fibers were observed, also the gradual exchange of type III collagen to type I, increased fibroblast show significant (p=0.0001) from day 16 until day 40, the expression of collagen was significant (p=0.0001) from day 16 until the end of the study. It was statistically significant correlation between neutrophils and macrophages (p=0.00018), collagen and eosinophil (p=0.03) and fibroblasts and collagen (p=0.02). The animals in the CG do not present histomorphometric improvement during the study. Conclusions. We conclude that the cell produces triamcinolone acetonide and histomorphometric tecidual recovery in horses with pythiosis.