Been there and done that with both cooked and raw homemade food for my cats, usually just when one is elderly, ailing or has a special dietary need. It may be in the works again soon...
So sorry to hear your dogs were poisoned. Nexgard is an anti-parasitic thing, right? I am skittish about all such products, and hence put up with fleas instead. I wish there were a safe and natural way to get rid of those!
Nexgard is a flea and tick chewable. Now I use the Seresto collar if needed because it can be removed. They do fine as long as you get the real thing and not a knock off collar. Fleas and ticks are a huge problem in the south. I powder the inside and outside with diatomaceous earth instead of using sprays but sometimes that’s not enough. My dogs won’t take anymore chewables. I get pure ivermectin tablets from a Canadian pet pharmacy for heartworm prevention.