A Deficiency Disease of Foxes Produced by Feeding Fish

Abstract

Chastek paralysis is an economically important acute disease of foxes occurring in violent outbreaks on ranches where uncooked fish is included as 10% or more of the ration. It causes a high mortality among nursing pups and intrauterine death of fetuses. The disease may easily be produced experimentally with a diet containing fresh carp, and can be prevented by adding large amounts of thiamine to the same ration. Characteristic neurologic symptoms occur and diagnostic lesions, identical with those of Wernicke's hemorrhagic polioencephalitis of man, are found in the brain. Pathologic findings, limited therapeutic field trials of thiamine and histories of ranch outbreaks confirm the experimental evidence that Chastek paralysis is fundamentally a B₁ avitaminosis. How fish can induce a deficiency of vitamin B₁ is unknown, but it is suggested there may be a chemical splitting of thiamine by some constituent of fish.