I was giving the cats their nightly can of merricks and when I opened it I found a big black spot that covered some of the top of the can of food. I dug into the can and found some of the chunks of meat also had specks of black. I have never seen this in the food before and I have gone through 4 cases of it already (of the same flavor). What could this be that I found in there food, I didn't feed them the can and searched through the next can and found nothing out of the ordinary. I have never seen that in their food before.