Successful potassium iodide treatment for rhinofacial pythiosis in sheep

•Pythiosis is a chronic inflammatory disease caused by the oomycete Pythium insidiosum.•Pythium insidiosum is an important agent for causing granulomatous lesions in sheep.•The disease was successfully treated in 11 out of 13 sheep.•Clinical recovery occurred after the disappearance of the palate and dental pad lesions.Potassium iodide is a suitable drug to treat sheep pythiosis. Pythiosis in sheep is an important disease in Brazil, which could cause rhinitis, dermatitis and alimentary tract inflammation. It is caused by the aquatic oomycete, Pythium insidiosum. The rhinofacial pythiosis causes facial deformity and upper respiratory tract clinical signs associated with necroproliferative masses occupying the rostral nasal cavity and hard palate. Little is known regarding the therapy, prophylaxis and pathogenesis of this disease. During the 6-year study, we examined 13 sheep presenting rhinofacial pythiosis. The diagnosis was performed through biopsy of the rhinofacial lesions followed by histopathology and immunohistochemistry using specific antibodies against P insidiosum, polymerase chain reaction and an indirect enzyme-linked immunosorbent assay. This study presents the clinical findings of a potassium iodide treatment of rhinofacial pythiosis in sheep. All sheep were treated with 10 ml of 10% potassium iodide solution, administered orally every day during 63–120 (mean 85) days. Among treated sheep, 84.6% demonstrated complete recovery. Potassium iodide therapy may treat rhinofacial pythiosis in sheep.