Pathology of natural Przhevalskiana silenus infestation in goats.

Among the arthropods causing diseases to animals, myiasis causes a broad range of infestations depending on the location of larvae and its developmental stages on the body of the host. These infestations reduce host physiological functions, destroy host tissues and cause significant economic losses to livestock worldwide. This study was conducted to find out the pathological changes of goats tissue infested with Przhevalskiana silenus. Goat warble fly infestation (GWFI), improperly named goat hypodermosis, is a myiasis caused by larvae of P. silenus. Out of 16,250 goats examined in the slaughter house in the studied area, 433 (2.67%) were infested with warble fly. The minimum and maximum rate of infectivity was 7 and 84 with an average of 32.4 warbles per animal. Histopathological examinations were carried out on the infested subcutaneous tissues. Infiltration of the mononuclear cell types, tissue necrosis, pyogranulomatous reaction, hyalinization, mineralization, muscle fragmentation, oedema, and hyperemia of arterioles and capillaries were the most important microscopic findings associated with different developmental stages of P. silenus instars in the goats. The results of this survey indicated that GWF is a widespread infestation in Shiraz, Fars Province, southern part of Iran.