Amprolium-induced cerebrocortical necrosis (CCN) in dromedary racing camels

Amprolium was successfully used to induce cerebrocortical necrosis (CCN) in dromedary racing camels, only when they were fed on a barley diet. Camels which were fed on hay ad libitum did not suffer form CCN, although their thiamine pyrophosphate (TPP) reached similar levels as in camels fed on barley. The reason for this phenomenon is discussed. Five camels which suffered from CCN had TPP values of 80-115% and were euthanized on humane grounds when they were in lateral recumbency. Pathohistological investigations revealed a polioencephalomalacia of the dorsal cerebral cortex with oedema and status spongiosus. Cerebral autofluorescence was observed under ultraviolet light. The major clinicopathological changes were a slight anemia and a decreased potassium value whereas glucose, muscle enzymes, leucocyte counts and differential counts were elevated. A TPP effect of 12% was found during this study in healthy dromedary racing camels and symptoms were observed when TPP values reached 80-115%. The test is now being widely used during the camel racing season.