Polio, polioencephalomalacia, is a disease caused by a deficiency of thiamine and is seen most commonly in lambs on high grain diets. The first sign of the disease is blindness. If your lamb bumps into things that it ordinarily would see and avoid, he may be showing signs of blindness. An injection of 3 cc of thiamine in the muscle will correct the condition.
If the first symptom of blindness is missed, the lamb will begin to appear wobbly in the rear end. This may be misdiagnosed as lameness. A day later, the lamb may be unable to get up but can still sit up and will be found on his side and unable to hold his head up. Finally, the lamb will die in convulsions. The course of the disease from the first sign of blindness to death will take approximately 5 days if not treated. The further in the disease course the treatment occurs, the longer it will take the lamb to recover. Generally, it will take 10 days before the lamb will begin to eat again.