Abstract
A six years old pleuriparous Arabian mare was presented with a history of infertility from last two years. The per-rectal examination of genitilia detected presence of a large tumor like mass involving the right ovary while the left one was normal. Transrectal ultrasonography indicated an enlarged mass of mixed echogenecity measuring app.15x12 cm on ovary. Surgical removal of the affected ovary & associated tumor through standing laparotomy under the effect of paravertebral nerve block was successfully adopted. The animal recovered uneventfully. The histopathological examination confirmed the mass to be a teratoma, containing hair tufts, straw coloured fluid, cartilaginous and bony tissues along with black melanin like pigmentation.