The present invention provides vaccines and methods for making the vaccines that actively or passively protect an equid or other animal against Sarcocystis neurona. In particular, the present invention provides vaccines that provide active immunity which comprise a polypeptide or DNA vaccine that contains or expresses at least one epitope of an antigen that has an amino acid sequence substantially similar to a unique 16 (.+-.4) kDa antigen and/or 30 (.+-.4) kDa antigen of Sarcocystis neurona. The present invention further provides a vaccine that provides passive immunity to Sarcocystis neurona comprising polyclonal or monoclonal antibodies against at least one epitope of an antigen substantially similar to a unique 16 (.+-.4) kDa antigen and/or 30 (.+-.4) kDa antigen of Sarcocystis neurona.