Hi
I am sorry for worrying everyone but I know alot of people on here use it so I had to post it. From what I read on link the problems where seen immediately and resulted in vomiting, diarrhoea, heart problems and death in a couple of cats. I am not sure if all the food was affected so if you fed it months ago and your cats are seemingly fine now then I would try not to worry. I dont know wheter a blood test would help i.e help reveal any organ damage if anyone is still worried. Maybe speak to your vets about a full blood panel to look at internal organs including liver and kidneys.
