Food safety
Can dogs eat spinach & kale?
Yes, but be careful
Fine in small amounts as part of a meal. Large quantities aren't ideal for dogs with kidney issues.
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.