Anatomical and Morphometric Study of Middle Ear Ossicles in Lori Sheep and Native Cattle of Shahrekord Region

BACKGROUND: The ossicles comprise three small bones (malleus, incus, and stapes) known as the smallest bones in the body that play an essential role in transmitting sound to the inner ear. OBJECTIVES: The study was conducted to compare the structure of the middle ear in native sheep and cattle. METHODS: To study the details of middle ear ossicles in Lori sheep (n=5) and native cattle (n=5), bio-anatomical parameters of the malleus, incus, and stapes ossicles were measured. Animals were male and adult. In this study, the ossicles were carefully described by the appropriate devices, and after separation, the ossicles were measured using a caliper and digital scales. Bio-anatomical changes were evaluated under magnification provided by stere-omicroscope. RESULTS: The cow's middle-ear ossicles differed from those of sheep in some details. The results revealed obvi-ous differences in length, width, and thickness of malleus, incus, and stapes in cows compared to sheep. However, further differences were observed in the malleus compared to the other two ossicles when the ossicles of the two species were evaluated. After examining the two studied species, the least difference was observed between the ossicles of the two animals in the stapes. CONCLUSIONS: To conclude, this study could compare middle ear ossicles between sheep and native cattle in the Shahrekord province. Anyway, it is conceivable that the biometric sizes of the middle ear ossicles may be af-fected by animal species.