Sure. In 1995 Nature's Recipe recalled their food because of animals vomiting the fungus-laced dog food.
In 1999 Doane Pet Care recalled some dog food when some dogs died because of a toxin present in the food.
Another company recalled their food when too much vitamin D was added, which killed the animals.
When meat-by-products are used, the food can contain bone, feathers, road kill, and even euthanized animals from vet clinics. Yes, all those ingredients are legal and have been put into dog food. Did you get a batch of food that was made with inferior ingredients because a slaughter house or veterinary clinic made Purina a great deal on some particularly nasty leftovers? That happens more often than you may think.
Money takes presidence over an animals health, so keep that in mind. Vets are not opposed to profiting from inferior food, so make up your own mind on what is happening with your dogs.