A University of California, Davis pilot study found that the combination of melamine and cyanuric acid can be deadly when eaten by cats.
The study, led by veterinary toxicologist Birgit Puschner and colleagues at the California Animal Health and Food Safety Laboratory in the UC Davis School of Veterinary Medicine, found that cats that were fed pet food spiked with both melamine and cyanuric acid quickly experienced acute kidney failure. Cats that received food that only had melamine or only had cyanuric acid showed no ill symptoms.
Puschner and colleagues found that the cats that received both melamine and cyanuric acid developed fan-shaped crystals in their urinary tracts. Such crystals were not normally observed in healthy cats.
The three cats that were fed pet food with both melamine and cyanuric acid became sick within 12 hours, began to vomit, lose their appetite, and showed signs of kidney failure.
After the exposed cats died, it was found that their tissues had the same kind of kidney damage detected in animal necropsies during the pet food recalls.
“The results of this study demonstrate that a single oral exposure of cats to melamine and cyanuric acid can result in acute kidney failure,” said Puschner. “The study also provides information that will help veterinarians better diagnose the causes of kidney failure in cats. The data will make pet food ultimately safer because now we know what to look for.”
Scientists suspected that both melamine and cyanuric acid played a role in the illnesses of animals that ate the recalled pet food; however, there was no information on the toxicity of the two chemicals in combination.
The research team suggests that, in order to provide more extensive data for a risk assessment of contaminated food, further studies are needed to determine the lowest dose of melamine and cyanuric acid that can cause kidney failure in cats.