Chinese authorities have admitted that some ingredients used to make petfood did contain melamine. According to a report in USA Today , the admission led to increased investigations into two Chinese companies and their links to enormous animal food recalls here, which also noted that China claims melamine did not harm pets.

"There is no clear evidence showing that melamine is the direct cause of the poisoning or death of the pets … China is willing to strengthen cooperation with the US side … to find out the real cause leading to the pet deaths in order to protect the health of the pets of the two countries," Beijing's Ministry of Foreign Affairs was quoted as saying by USA Today .

Meanwhile, USA Today reports that Chinese police sealed Binzhou Futian Bio-Technology's headquarter offices. The company exports rice protein concentrate to the United States for use in petfood.

The US Food and Drug Administration announced it will be going to China to conduct inspections; however, there is concern over that country's "vast and fragmented food-processing industry."