Interesting information. Thank you. It is interesting what the vet had to say.
About 9 months ago, the Republic of Panama purchased some poisoned cough syrup. It contained coolant. The syrup came from a pharmaceutical house in Spain, which in turn had purchased the ingredient containing the poison from China. Many folks died.
Melamine (Fire-retardant, nephrotoxic, stain erasing fertilizer)
Mentions the protein angle.