Associated Risk Factors with Neospora caninum and Neosporosis: A Review

Abstract

Neospora caninum is an obligate intracellular protozoan parasite causing neosporosis, a disease presenting great importance in a variety of domestic and wild animals worldwide, particularly dogs and cattle are the most affected hosts. It is among the common causes of bovine abortion and one of the primary threats to intensively raised dairy and beef cattle, causing huge reproductive and economic losses. Serological tests, including seroreactivity tested by ELISA and IFAT were the most common methods used for the diagnosis of infection. The parasite has a complex life cycle that entails three major stages: sporozoites, tachyzoites and bradyzoites. Vertical transmission is the form of transmission in cattle; the parasite is passed from dam to fetus trans placentally. Dogs are the final hosts of the parasite that excretes oocysts with the faeces and contaminates environment particularly feed and water. Closeness to infected dogs is significantly related to higher prevalence of infection thus a close association between cattle and sick dogs has been highly incriminated. Exact worldwide figures are not available. Pharmacological treatments against N. caninum have been explored, and compounds such as piritrexim, monensin, pyrimethamine and trimethoprime have demonstrated inhibitory activity against the parasite ultimate development in cell culture. There is, however, no truly effective cure. Consequently, the control of vertical transmission is still the most realistic and the most effective approach to control, thus requiring enhanced biosecurity measures in order to manage dogs on farms as well as more sustainable therapeutic or vaccine-based interventions.