Patologias micóticas e neoplásicas da cavidade nasal de pequenos ruminantes e equino.

Abstract

This thesis was constituted by four chapters that resulted in four scientific articles related to diseases of the nasal cavity in small ruminants and horses diagnosed at the Animal Pathology Laboratory, of the Veterinary University Hospital Prof. Dr. Ivon Macedo Tabosa, from the Federal University of Campina Grande, Patos, Paraiba. The first chapter describes the epidemiological, clinical and anatomopathological findings of meningoencephalitis secondary to Pythium insidiosum rhinitis in sheep that presented mild dyspnea and neurological signs. In the nasal cavity there was a red-black, irregular and friable mass that bilaterally compromised the nasal septum and the rostral portion of the nasal turbinates. In the brain, diffuse thickening of the leptomeninges of the cerebellum and ventral portion of the brain stem was observed by yellowish granular material associated with hyperemia of the vessels. On the floor of the fourth ventricle there was deposition of yellowish, irregular and slightly granular material that protruded towards the obex and displaced the cerebellum dorsolaterally. Microscopically, there was pyogranulomatous, eosinophilic and necrotizing rhinitis, and fibrinossupurative, eosinophilic and necrotizing meningoencephalitis, both associated with thrombi, vasculitis and negative images of intralesional hyphae. The hyphae were impregnated with silver and immunopositive for the anti-Pythium insidiosum antibody. The second chapter refers to the clinical and pathological characteristics of rhinitis caused by Exserohilum rostratum in goats in which he had anorexia, dyspnoea and deformity of the face for two months. In the nasal cavity, there was a focal area, extensive yellow-brown, irregular, ulcerated and friable, which drained purulent secretion affecting the nasal vestibule up to the caudal portion of the dorsal concha. The lesion was characterized as rhinitis and pyangranulomatous and necrotizing osteomyelitis, associated with fungal structures. Morphologically, hyphae were characterized by thin walls, slightly tortuous and rarely, multiple chains of individual conidia or in groups and pigmented clamiconides. They were positive in the special histochemical stains of Fontana masson, methenamine nitrate of silver of Grocott and periodic acid of Schiff. The agent was determined through microbiological isolation associated with molecular identification. The third article reports on goat nasal T-cell lymphoma, which showed dyspnea and respiratory noise. In the sagittal section of the head, a pinkish-gray mass, smooth, multilobulated, smooth surface, strongly adhered to the rostral portion of the dorsal concha and occluding the dorsal nasal meatus in the right and left nasal cavities was observed. Histopathological examination revealed a neoplasm of lymphocytic origin, confirmed T-cell lymphoma by immunohistochemistry. In the fourth chapter, he presents a case of primary leiomyosarcoma of the nasal cavity in horses that presented a decrease in sports performance and bilateral purulent nasal secretion with approximately six months of evolution. In the nasal cavity, an irregular, yellowish, shiny, fibroelastic mass was observed, obstructing the left nostril. In the histopathological examination, spindle-shaped neoplastic cells were observed, which stained red in the Masson Trichomic stain and there was positive immunostaining for antibodies 1A4, HHF35, Desmina and S100. The diagnosis of leiomyosarcoma was based on the morphotintorial aspects of the cells and confirmed through immunohistochemistry. Among such new anatomopathological conditions diagnosed in LPA/HVU/UFCG in production animals, it was found that infectious and neoplasia occur sporadically and are responsible for the death / euthanasia of patients. They attend with similar and nonspecific clinical signs, which makes the clinical and macroscopic diagnosis difficult. It is necessary to use histopathological, immunohistochemical, microbiological and molecular exams to confirm the etiology of each condition.