Parasitism such as helminthoses, ectoparasitism and haemoparasitism is a major problem in the health management of animals as it is worldwide in distributed. This study is aimed at investigating the prevalence and risk factors associated with the occurrence of parasitic diseases of horses diagnosed in Osun State Nigeria. From January 2006 to December 2015 a total of 864 horses were presented for treatment in the veterinary hospitals of the state, of which 720 (83.33%), 504 (58.33%), 152 (17.59%), 80 (9.26%) and 72 (8.33%) were diagnosed for tick infestation, babesiosis, helminthoses, trypanosomiasis and mange respectively. The diagnoses were carried out based on case history, physical examination, clinical signs and labouratory confirmation. There was no defined pattern in the yearly and monthly prevalences of parasitic diseases from this study. Age, sex and season were statistically (P>0.05) associated with the occurrence of equine parasitic diseases. This study showed that parasitic diseases are endemic in Osun State Nigeria, with tick infestation, babesiosis and helminthoses been of major concern. There is need for a radical preventive measure to curtail the disease condition so as to improve on the health, wellbeing and performance of horses.
Key words: Prevalence, risk factors, parasitic diseases, horses, Osun State