Characterisation of Serum Acute Phase Protein Response During Foot-and-Mouth Disease Outbreaks in Cattle in Niger State

Acute phase proteins are blood proteins whose concentrations change significantly in response to infection, tissue damage, and inflammation, serving as objective biomarkers of systemic disease severity and treatment response. Foot-and-mouth disease continues to cause devastating outbreaks in cattle herds in Niger State, North Central Nigeria, with significant production and economic losses. Characterising the acute phase protein response during natural foot-and-mouth disease outbreaks provides insight into the systemic inflammatory burden and may offer prognostic markers to guide supportive therapy decisions. This study measured serum haptoglobin, fibrinogen, serum amyloid A, C-reactive protein, and albumin in cattle during active foot-and-mouth disease outbreaks at farms in Minna and Bida districts. Fifty cattle with confirmed foot-and-mouth disease by antigen ELISA and 25 healthy in-contact vaccinated cattle from the same farms served as controls. Samples were collected at diagnosis, day 7, and day 21 of the outbreak. Serum amyloid A concentrations were massively elevated at diagnosis, with median values over 600 micrograms per millilitre versus undetectable levels in controls. Haptoglobin and fibrinogen were also significantly elevated at diagnosis. Albumin, as a negative acute phase protein, was significantly reduced in diseased animals. By day 21, serum amyloid A and haptoglobin had declined significantly but remained above control values in animals with persistent lesions. Fibrinogen showed the slowest normalisation. These findings characterise the acute phase response to foot-and-mouth disease in Nigerian cattle and identify serum amyloid A and haptoglobin as sensitive markers of disease activity relevant to outbreak monitoring. Keywords: acute phase proteins, foot-and-mouth disease, cattle, serum amyloid A, Niger State.