Right ventricular failure and ascites in broiler chickens caused by phosphorus-deficient diets.

Phosphorus-deficient diets fed to broiler chicks from day 1 to day 21 induced rickets. Some chicks were stunted, but most grew well, though they had increased respiratory rates, high arterial carbon dioxide partial pressure, and low oxygen partial pressure and were polycythemic. Most of the broilers that died showed signs of pulmocardiovascular abnormalities, some died from hypoxia, and some died from right ventricular failure with or without ascites. Many broilers had mild to marked right ventricular hypertrophy and dilation with or without ascites when examined at 21 days. It is suggested that right ventricular hypertrophy and dilation was a response to pulmonary arterial hypertension caused by chronic hypoxia, which resulted from inability to breathe normally because of poor rib strength and infolding. When right ventricular failure occurred, it was secondary to right ventricular hypertrophy and dilation.