Vitamin B12 deficiency in newly weaned goat kids associated with clinical infection with Eimeria arloingi.

A severe outbreak of diarrhea associated with poor growth was reported in ten newly weaned goat kids that originated from a research farm (Group A). Two of these kids underwent necropsy examination. Five goat kids of the same age maintained in the same pen showed no clinical signs (Group B). The clinical, gross pathological and histopathological features of the clinically sick animals were consistent with severe coccidiosis. Group A animals had significantly lower levels of serum vitamin B12 (<200 pg/ml) compared with group B animals (2000 pg/ml). In addition, kids belonging to group A had significantly higher Eimeria arloingi oocysts per gram (OPG) of faeces (101,400/g) compared with kids of group B (9,154/g). Microscopy and molecular tools (18S rRNA and COI genes) confirmed that the goat kids were infected with the caprine protozoan parasite E. arloingi. This study provides a definitive association between low levels of serum vitamin B12 and clinical E. arloingi infection, and also provides support to our previous studies that demonstrated how low levels of serum vitamin B12 leads to an impairment of neutrophil function and thereby potential lowered immunity to pathogens.