Over 40 laboratory tests were initially conducted to rule out various pathogens and environmental toxins. These tests were used to try to identify potential viruses carried by humans, pigs, or both, including rotaviruses, adenoviruses, hepatitis A, and hepatitis E. They also tried to identify bacteria such as Salmonella and Escherichia coli, and parasites such as Giardia and Cryptosporidium that could be causing the symptoms. All were ruled out. Neurodegenerative diseases were considered specifically because of the similarity of symptoms and animal involvement thus included investigation of prion associated diseases such as bovine spongiform encephalopathy (BSE), chronic wasting disease (CWD), and variant Creutzfeldt–Jakob disease. These all have highly transmissible pathogenic agents that induce brain damage. Since no pathogenic agent had been found, these diseases were ruled out as being related. Next two very similar neuropathies were ruled out. Guillain–Barré syndrome induces an acute autoimmune response which affects the Schwann cells in the peripheral nervous system. Guillain–Barré syndrome is usually triggered by an infection that causes weakness and tingling that may lead to muscle loss. This condition may be life-threatening if muscle atrophy ascends to affect the pulmonary or cardiac systems. So far, no infectious agents have been found that relate to the current disease,<unk> . They looked at chronic<unk>  demyelinating polyneuropathy which is characterized by<unk>  weakness and sensory impairment in the arms and legs. Damage occurs to the myelin sheath in the peripheral nervous system. As doctors at the Mayo Clinic were beginning to note, the problem they were seeing in<unk>  was occurring in the spinal nerve roots.
Progressive inflammatory neuropathy
Chemotherapy-induced peripheral neuropathy
Acute motor axonal neuropathy
Diabetic neuropathy
Small fiber peripheral neuropathy
Vasculitic neuropathy
Alcoholic polyneuropathy
Proximal diabetic neuropathy