Abomasitis associated with halofuginone intoxication in pre-weaned calves

Background In this case series abomasitis as a consequence of halofuginone intoxication is suspected. Case presentation Seven Belgian-Blue calves with complaints of anorexia and weight loss were presented to an university clinic. Ultrasonography showed thickening and edema of the abomasal wall in all cases, suggesting abomasitis. Abomasitis was confirmed on necropsy in three cases. Retrospective analysis clarified the uptake of an overdose of halofuginone lactate (348–421 µg/kg/day). Four animals fully recovered after removal of halofuginone lactate administration, therapy for comorbidities (pneumonia, diarrhoea) and supportive therapy. Conclusion To the authors’ knowledge, this case series is the first report associating halofuginone lactate use with abomasitis. This was suspected after clinical improvement of four of the presented animals after terminating the administration of a high dose of halofuginone lactate, and exclusion of other possible causes. Underlying mechanisms are still unclear.