I read this and straight away googled problems with nature diet dog food. Loads of results and the problems date back quite a few years.

Rancid, foul smell/rancid meat smell/battery acid smell, substandard packaging/blown packs/problems with pack seals, mould, bits of bic pen and other plastic in the food, recalls, dogs ill ...

I wouldn't feed my dog anything with that many bad reviews. Lots of people say they complained to the company and all say they were reimbursed etc. The company should be looking at solving the problem of the packaging (if that's what it is) not just reimbursing everyone who complains (so they don't take it further)

I keep some for emergency use, Chico has it if I feed anything containing chicken (I feed mine raw) as he chucks it back, I haven't had any problems so far.