Black marks at bottom of dog food tin

A question about : Black marks at bottom of dog food tin

We bought some dog food from Pets at Home about 6 months ago and in a log of the tins there were black marks at the bottom of the tin. Not sure what it was, but my partner swears its mold.

It was PAH own brand so we complained only to be told that it was part of the manufacturing process and perfectly normal.

We stopped using it, until today that is! Stupidly I went to PAH and ended up coming out with 48 tins of it (the missus was none to happy when I got home!), must have been on auto-pilot!

Anyway, just fed the dog, first tin opened and black marks at the bottom of the tin again.

The dog doesn't get ill off this, and PAH were adamant that it's not harmful and perfectly normal, but has anyone else come across this before?

Best answers:

• Did PAH explain what it actually was? I'd want more details to reassure me it was OK. It could well be harmless - I bought some cream crackers for myself recently which had black marks on them, turned out it was carbon marks from the cooking process.
• What kind of black marks? Mould doesn't normally look like black marks, and would usually be on the meat and not the tin.
• Did it look anything like this?
  This is a PAH food & I raised a complaint which they investigated and the manufacturer said it was seaweed being added too quickly - and i was told it had been rectified so bit disappointing it hasnt been
  If you dont want ro use it - take it back
  PAH are really good at accepting returns
• extremely unlikely to be mould. There isnt any oxygen in the tin for mould to grow, and if it did it would be white fur on the meat
• I reckon seaweed like rising from the ashes says.