Phosphorus maximum for cat food on the horizon

Four weeks into the test period of a nine-month study investigating the link between cats' health and phosphorus in their food, Dr. Jonathan Stockman and his team cut the trial short. Some of the 24 feline subjects had lost their appetites and were shedding weight and vomiting. The kidneys of 22 cats appeared concerningly bright on ultrasound images.

The first study to suggest a link between high levels of dietary phosphorus and kidney disease in healthy adult cats had been published more than 20 years earlier, but now Stockman was seeing the negative effects in real time.

This story was published on May 14, 2026.