Gout, an ailment many associate with the over-consumption of rich foods, is a condition not confined to humans. Periodically, flocks of egg-laying hens may be afflicted, due to the abnormal accumulation of urates, the salts of uric acid. Ralph Ernst, a UC Davis Cooperative Extension poultry specialist, notes there are two different types of chicken gout, but many different causes. Articular gout affects the joints, particularly the feet, and causes them to appear enlarged and deformed. More common in layer hens, however, is visceral gout, an accumulation of urates in the kidney, heart, liver and other internal organs. "Kidney stones in chickens? You bet," Ernst says. "It's not a widespread problem but it is common enough to cause serious economic losses to producers." Just as with humans, a nutritional excess of protein in the diet can cause the condition. But genetics, environmental toxins, and infectious agents can also play a role. Ernst outlines a number of steps producers can take to deal with the problem in his April 1995 California Poultry Letter.