RESUMO
In the vicinity of the river Aquidabán in Eastern Paraguay occurred in the last years an endemic disease within cattle herds which killed thousands of heads (Mal de Aquidabán [MdA]). The disease was seen in form of an afebrile, paralytic condition characterized by muscle tremors, swaying of the hind quarters, recumbence and sudden death of the animals. Therefore it was described as "Bovine Paraplegic Syndrome". Comparable symptoms in adult cattle have also being seen in Eastern and Central Venezuela. After we found in the peritoneal fluid of 2 animals, which died under typical symptoms, toxins of C. perfringens toxovar D, we started to investigate the occurrence of C. perfringens in the feces of clinical healthy animals on farms, where MdA was diagnosed before. There we found 73% of the isolated strains belonging to toxovar D. In herds with no case of the disease toxovar A was isolated up to 90%. The next step was the production of a vaccine (anaculture) with a high toxin producing strain of C. perfringens toxovar D. 2000 cattle were vaccinated for 3 years twice a year. None of the vaccinated animals diseased. In 2 control-herds some cases of MdA occurred. But we became quite sure that MdA was an infectious disease, when we started to vaccinate cattle of unvaccinated herds where MdA suddenly occurred. One or two animals died in the next 2 days and after this period the endemic disease was immediately stopped.