Abstract

Twelve suckling foals with nasal discharge, aged five to seven months, were treated in field conditions with the application of trimethoprim and sulfadiazine, anthelmintics and macrolids with rifamycins. Five days after clarithromycin with rifampin was administered, one foal died, and a second foal became colicky. The second foal underwent colic surgery and was then euthanised due to severe large colonic oedema. This finding was identical to that of the first non-survived foal. The following day, colic behaviour and colitis were present in additional two foals. These foals did not respond to anti-endotoxemic and supportive therapy, and when circulatory collapse with pleural effusion developed, they were euthanised. The remaining eight foals were diagnosed at the home stable with the same findings. Ultrasound confirmed massive oedema of the large colon, but with only slight changes in the lungs. All remaining foals were managed with transfaunation. Five of the foals improved within twelve hours, and the other three, those with the most severe colon oedema, were treated intensively at the clinic with antibiotics, repeated transfaunation and supportive care. The main symptoms of significant disturbance of the microbiome included colic, colon oedema and, in the worst-affected foals, final stage pleural effusion. Repeated transfaunation significantly improved the health status of the foals and halted the development of the symptoms displayed by the first four foals.