Background
Ethylene glycol (EG) (antifreeze) toxicosis has mostly been reported in dogs and cats, while reports on EG toxicosis in cattle are sparse. We report EG toxicosis in 25 milk-fed calves associated with a leak in the cooling pipes in a milk taxi. The milk taxi was connected to a geothermal heating system in which EG was used as antifreeze.

Case presentation
Although the assistant responsible for feeding milk to the calves observed a few blue-colored droplets of liquid on the surface of the milk in the milk taxi and suspected EG contamination, the milk was fed to the calves. Within hours, the calves became depressed and some died within the next 2 days. Necropsy and histopathology revealed widespread severe acute renal tubular necrosis with numerous birefringent crystals in the tubular lumen. Biochemical analysis of serum showed severe damage to the kidneys (marked azotemia) and hypochloremia, hyponatremia and hyperkalemia; findings consisting with metabolic acidosis. After feeding the calves, the assistant inspected the milk taxi and found a leaking cooling pipe.

Conclusions
The suspected EG toxicosis was confirmed by the observation of renal tubular necrosis, numerous intratubular crystals, and metabolic acidosis. EG toxicosis due to leaking pipes connected to a geothermal heating system has not been reported previously. Alternative antifreeze products that are less toxic than EG are recommended for use if there is a risk of contamination of human and animal foodstuffs in case of a leak in the system.