Pythiosis cutaneous in horses treated with triamcinolone acetonide. Part 2. Histological and histochemical description

Objective. The study aimed to evaluate the histomorphometry tissue recovery process of the skin granuloma of skin pythiosis in horses treated with triamcinolone acetonide. Materials and methods. We conducted a descriptive study, not probabilistic in convenience animals with cutaneous pythiosis. 24 horses were used with cutaneous pythiosis, a group of 12 animals was administered 50 mg of intramuscular injection of triamcinolone acetonide (TG) and the other group was not applied any treatment (CG). Are tissue biopsies performed for histological and histochemical evaluation and stained with hematoxylin eosin (HE), Gomori trichrome (GT), picrosirius red polarization (PR/P), Grocott methenamine silver (GMS) and periodic acid-Schiff (PAS). Results. It is noted that in TG inflammation was gradually decreasing, as evidenced in decreased fibrin layer leukocyte, PMN and phenomena Splendore Hoepli, also in increased angiogenesis, epiteliogénesis, and increasing the overall amount of fibroblasts and collagen fibers, anyway in the progressive replacement of collagen type III to type I collagen at the end of the process, and that the presence of intralesional pseudohyphae of Pythium insidiosum reduces it to the second week. Neither of the animals in the CG showed improvement in histological and histochemical characteristics of pythiosis and maintained equal to the first day throughout the study. Conclusions. The use of triamcinolone acetonide is a good therapeutic alternative for the treatment of granulomatous pythiosis wounds in horses with 100% clinical recovery and demonstrated with histological and histochemical findings.