Onions (whole, powdered or cooked): Onions contain thiosulphate, which is toxic to dogs. Thiosulphate can cause Heinz Body anemia in dogs- essentially leading to the breakdown of red blood cells while circulating in the body. The first symptoms to look for are vomiting and diarrhea as well as a lack of appetite. Signs of poisoning may start up to a few DAYS after the dog has consumed onion. Poisoning can occur after ingesting a single large amount of onion or repeated small amounts of the food. Garlic also contains the chemical, although not as much, and should also be avoided. The condition will improve once consumption ceases.
Of course, safety should come first. Don’t ever leave your dog alone while on a treadmill! The same goes for tying your dog to it - I don’t recommend doing this as it’s just too easy for your dog to be injured or even strangled.
And you know how you start your own workout by warming up and then cooling down afterwards? You should do the same with your dog! Wait at least an hour after feeding your dog to put him on the treadmill to prevent bloat or twisted stomach. It’s also a good idea to limit water before and after a workout for the same reasons, as well as to prevent any puddles on the treadmill.
Take your time with this training. You want your dog to love the treadmill, not hate it. Some dogs may need a few days to be comfortable with the sound and motion of the moving belt, while others will be on there and looking like it’s no big deal almost right away.
One last tip for training on a dog treadmill: don’t ever give corrections on the treadmill. As I said, it’s important that your dog is completely comfortable with the machine. It’s also not safe for your dog to wear a training collar, such as a martingale, choke chain, or prong collar, while exercising here. You don’t want to risk hurting your dog if the collar was to get caught on anything! Instead, use a flat-buckle collar or a harness.
When correcting unacceptable behavior, timing is critical. Do not wait for the lunge; at the first hint of aggression, such as a stare, correct with a firm "No" and a quick (but not punishing) leash correction, and redirect the dog's attention to you. You must keep control at all times and show the dogs YOU are the alpha. Don't be alarmed if they don't warm up to each other immediately. Either dog may engage in aggressive posturing, barking, marking, housetraining accidents, and possessiveness over toys and people. (If this persists beyond a week or two, consult a specialist.)