Food safety
Can dogs eat sweetcorn kernels?
Yes, but be careful
Kernels off the cob are harmless in small amounts. The cob is the danger.
Being honest about this
Dogs differ, and amount matters — a crumb of something rich is not the same as half a packet. Treats of any kind should stay under a tenth of what your dog eats in a day. If you're unsure, your vet would far rather take the call.