Eight months after an industry-wide pet food recall affected thousands of dog and cat foods and perhaps an equal number of pets, researchers have proven a link between the combination of melamine and cyanuric acid, chemicals found in tainted food, and feline kidney failure. “The contaminants found in recalled food are causative agents seen in the outbreaks,” said Birgit Puschner, DVM, PhD, a board-certified toxicologist and coauthor of the study. “We demonstrated that.”

In addition to closing the book on how chemicals caused fatalities, the research data should be considered during kidney failure diagnoses, Puschner said.

“It’s one of the etiologies, in addition to anti-freeze and lily ingestion” she added. The research was published in the November issue of The Journal of Veterinary Diagnostic Investigation, an official publication of the American Association of Veterinary Laboratory Diagnosticians (AAVLD), a group that tracked recall cases.

The recall, which dates back to March 2007, was sparked by the discovery of chemicals in pet foods that sickened pets. It has resulted in about 100 lawsuits and much industry confusion. At the time, medical professionals were stumped because the chemicals by themselves were not known to be fatal. This study proves, however, that when combined, melamine and cyanuric acid — which are used in plastics — cause acute renal failure in cats, Puschner said.

Kimberly May, DVM, MS, DACVS, who tracked the recall issue closely for the American Veterinary Medical Association, said the study provides clarification on the chemical interaction that caused the problem.

“We used a concentration similar to what was found in the recalled foods and saw renal failure,” she explained. Cats were given a single oral dose of the chemicals. Based on data obtained in feed studies conducted in April and May, pathologists cannot say that any concentration of the chemicals is safe. “Even at the lowest levels we used, it induced renal failure,” Puschner added.