PROTOZOAL ENCEPHALOMYELITIS OF DOGS INVOLVING NEOSPORUM-CANINUM AND TOXOPLASMA-GONDII IN NEW-ZEALAND

In a retrospective study of 15 cases of encephalomyelitis in dogs, thr ee cases of Neospora caninum and two cases of Toxoplasma gondii infect ion were identified using immunohistochemical staining of central nerv ous system sections. All cases of neosporosis showed ataxia and progre ssive hind limb paralysis due to multifocal non-suppurative meningoenc ephalomyelitis which was most severe in the spinal cord and base of th e brain stem. Neospora tissue cysts could not be distinguished morphol ogically from those of T. gondii using light microscopy, but electron microscopy confirmed their characteristic features. Although Neospora abortion in cattle has only recently been recognised in New Zealand, t his study has shown that neosporosis has been present in dogs since at least 1972.