Characterization of sulfur and sulfate toxicosis in cattle.

Sulfur and sulfate toxicoses are important causes of polioencephalomalacia (PEM) and feed refusal in cattle, resulting in decreased weight gain and increased death losses. The purpose of the study was to characterize the demographics of cattle with sulfur/sulfate toxicosis (ST), describe clinical signs and pathology associated with disease, and to identify potential sources of high sulfur/sulfate. Cattle submitted between August 2005 and April 2009 were separated into three groups: Group A had neurologic signs or histologic evidence of PEM, as well as confirmed exposure to elevated concentrations of sulfur/sulfate; Group B had neurologic signs and/or histologic evidence of PEM but no confirmed exposure to elevated concentrations of sulfur/sulfate; Group C had confirmed exposure to high sulfur/sulfate although no record of any pathology or clinical signs associated with ST. The following information was recorded when available: age, gender, production type, month of submission, clinical signs, pathology, and source of elevated concentrations of sulfur/sulfate. Statistical analysis was performed on data from Group A. Affected cattle were more likely to be females between three and 16 months of age (age, P<0.001; gender, P=0.022). A seasonal trend was not detected. Clinical signs in Groups A and B included neurologic signs and gastrointestinal problems (18/29); sudden death was reported in 11/29 cattle. Cattle in Groups A and B had PEM (16), meningoencephalitis (2), cerebral edema (1), gliosis (1), abomasitis (3), and/or cardiac or skeletal muscle degeneration, necrosis, and/or inflammation (5). Undifferentiated feeds were the most common source of sulfur/sulfate toxicosis.