Hemodynamic and ventilatory effects of skin-cooling in cattle.

Cooling the skin of cattle at an ambient temperature of 25 degrees C decreased cardiac output and increased systemic and pulmonary vascular resistances. Minute ventilation was reduced by about 50%. There was no change in alveolar ventilation as measured by arterial blood gases. These results indicate that thermoregulatory ventilation has significant cardiopulmonary effects in cattle at normal laboratory temperatures.