This invention provides compositions and methods for treating and vaccinating and inducing an immune response against a Her2/neu antigen-expressing tumor in a non-human animal. An exemplary method of treating a Her-2/neu-expressing tumor growth or cancer in a non-human animal, the method comprising the step of administering a recombinant Listeria comprising nucleic acid molecule encoding a fusion polypeptide, wherein said fusion polypeptide comprises a Her2/neu chimeric antigen fused to an additional adjuvant polypeptide is provided.