Dogs can sure get poisoned and by much of what is used to poison pests nowadays. Dogs will try anything they come across and don't know the difference about what theyre allowed to eat and what they are suppose to stay away from, and can from poison plants too, as well as other materials people have laying around the house
Unfortunately, yes. Last summer someone was throwing poisoned meat into a nearby dog park. Three dogs were killed and more had gotten sick. (If I ever find the person, they will get a taste of what they did.)
Yes.
Of course they 'can' .. If someone chooses to do so purposely or if they get into something that is poisonous or toxic.