Thiamine deficiency in beef cattle is possible. It results in a brain disorder called polioencephalomalacia (polio) that causes partial paralysis in the animal’s ability to rise. In attempts to rise, the ankles of the rear legs remain flexed or “knuckled over”. The brain disorder is an edema (fluid collection) on the brain. Prolonged pressure caused by the edema causes damage to the brain usually without recovery. Immediate treatment is necessary to remove the edema before brain damage occurs. Thiamine deficiency is caused by production of thiaminase enzyme which destroys thiamine in cattle that are on a high sulfate diet or water source or a combination of diet and water. A drastic change in the animals diet from low roughage (short grass) to grain supplements without hay commonly predisposes cattle to production on thiaminase in cattle.