The University of Guelph Laboratory Services department has posted images of crystals taken from a cat suspected to have ingested melamine-tainted food. Guelph hasn’t been able to identify the cystals yet, but mass spectrometry shows them to be 30 percent melamine and to have a different spectrum than ammonium urate or xanthine. Several veterinarians on VIN are reporting seeing crystals similar to those posted by Guelph.