can there be a low level case of Botulism, and is there a blood test for it?

My mother has developed lid drooping, muscle weakness, bowel problems, forgetfulness, loss of balance and is becoming progressively more helpless for no apparent reason. She has also lost 25 lbs. in the last 2+ months. She is notorious for eating stuff that has been sitting around forever in the fridge and out. Could she have a low level case of Botulism?

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