I usually buy ultra cheap canned dogfood to treat my dogs' evening meal. 1 can split up amongst 6 dogs. It's just a little treat, so I don't care that it's crap. When I was buying the cans at Big Lots, a lot of them were dented. I picked through the cans and picked (I thought) all undented ones. I specifically looked at each can. Now, several days later, when I'm looked at them, about half of them are dents either at the top or the side. DO I have to worry about botulism, or is that just bulging cans?
We get Iams (expensive) dented cans with the labels ripped off for about 30 cents each. I've never had a problem with the dented cans as long as there were no cracks or splits to let air in. Hard to get to work with the opener, though!!
I ran a pet store for 10 years- we had a lot of dented cans. Believe me, you WILL know if you open a can that was poorly sealed. I don't think I will ever forget that smell. We had 3 cans in all those years that were bad, out of thousands of dented ones. I wouldn't worry about it-usually just clumsy stockers.
I buy cases of canned food (the bigger 13oz-ish cans) which have been and continue to be stacked for a few months. There are always dented cans, maybe a dozen or so over 12-13 cases. Not one of them have been remotely compromised by the time I opened them.
And yes, if you opened one that had a vacuum breach, you WOULD know it, as it's basically rotting meat at that point
______________________________ The CoTH CYA - please consult w/your veterinarian under any and all circumstances. - ET