The study looked at how high levels of calcium in a dog's diet affect the absorption of calcium and phosphorous in their intestines. By testing the dogs' digestion, the researchers found that as dietary calcium levels increased, calcium excretion in feces improved, calcium digestibility decreased, and daily calcium absorption increased. On the other hand, phosphorous excretion in feces improved, but phosphorous digestibility and absorption decreased with higher calcium intake. This shows that dogs can adjust their calcium absorption by changing how much calcium they excrete, and that high calcium intake can lower phosphorous absorption.