My dog ate chicke skins that were boiled with a piece of onion. She got to the plate that had the skins on them there was no actual onions on the plate just the skins. Could that have caused her to pass away with in 5 to 10 minutes
Onions are poisonous to dog and cats, I've read many articles before on this but that long ago so I'm not entirely sure what they do just I remember reading they have a chemical that attacks red blood cells and causes symptoms of anemia. Even though their poisonous, a lot of things we don't consider poisonous ARE if eaten at the right amount. I've fed my cats onion products before (2 weighed 16 lbs. and one was about 25 lbs.) and one eats an onion product almost daily if not twice a day and all my cats are fine and that cat that continues to eat onions actually weighs less than your dog.
There are considerations to take into account though that makes your situation differ from mine. First is species, generally if a cat can't eat something, than a dog can eat more of that something before dying from it (so you already have that in your favor). Next is weight, like I said your dog weighs more than my one cat who eats onions all the time so that's good, means he is likely more able to tolerate the toxins in onions. Unfortunately though what wasn't on your dog's side is breed. Aren't French Bulldogs respiratory impaired? And like I said onions basically attack the respiratory system. By going after the blood, you don't have enough oxygen in your system to supply your organs with, putting your lungs on overdrive to make up for this sudden demand of oxygen. But there is also an unknown variable. And that is the individual. I only have one cat that still eats onions and that's because the other two (both of which weigh more than him) started showing pale gums which is a sign of anemia, proving to me that they can't handle their onions.
All that being taken into consideration, my gut feeling is that it SHOULDN'T have killed your dog. Even all my cats could've eaten what you described (and if I'm understanding right, your dog didn't actually eat the physical onions) and they would've been just fine. Cooking with onions probably does increase the risk factor of eating that food even if you don't eat the onions, but it would be INCREDIBLY SMALL. But since the two coincided together, I do feel inclined to say yes, since that is just too much of a coincidence otherwise. It probably was the onions and you just got really unlucky in that your dog happened to not be able to tolerate onions at all. Maybe your dog had a pre-existing condition that was aggravated by the onions (i.e. something wrong with the lungs or heart)? But without knowing if your dog was affected by anemia before she died, it's really hard to say anything for certain. There is always the chance that it wasn't something you did and it really was just a VERY unfortunate coincidence.
From what I could find quickly regarding toxicity, there is no general rule for dogs for dangerous dosage, but it is known that they will show signs of poisoning after ingesting 15g-30g per kilogram body weight in onions.
Some breeds are more susceptible to onion poisoning, the source specifically listing Shiba Inu and Akita here.
Other factors that can increase toxicity are existing medical conditions, e.g. poorly managed diabetes or weakened liver function.
All in all, a smallish onion on its own may very well be lethal for a smallish dog.
Ingesting much smaller dosages over a prolonged period of time can also build up, much in the same way as drinking tap water from old lead pipes will lead to chronic lead poisoning.
With many poisonous plants, cooking something in them without feeding the plant directly is not safe, as many toxins such as alkaloids are soluble in water, and as such can be transferred by cooking.
However, the source lists a lot of general symptoms of poisoning (i.e. salivating, stomach cramps, vomiting, diarrhea, etc), and the time passing until lethal anemia setting in as up to a week.
While I'm not a veterinarian, I would think that just 10 minutes until the dogs passing does not sound very plausible for poisoning being the main factor here, especially if no symptoms were showing prior to the dog passing.
At the very least, I would think that there must have been a serious medical condition that was undiscovered for this to lead to such an outcome, on top of breed having constricted airways to begin with as another answer mentions.
Or something more mundane but equally tragic, choking from getting a piece of chicken skin stuck in the airways from eating them too hastily, with the piece dislodging and going down only after a couple of minutes.
I know one case from an acquaintance where their dog fatally choked on a doggy cookie which are supposed to be perfectly safe, but nothing is in case of a freak accident.
To add my two cents, you write
no caughing she stood for a lil bit and sat down and then fell over
There is no way the onion caused her death.
I'm not a vet, but this sounds like a heart attack or something similar. I've heard similar descriptions from people who had dogs with a congenital heart disease. One moment the dog is ok, then suddenly they pause, stand around or sit down as if they blacked out and that's it. They are just gone.
I'm sorry for your loss, but as far as I know there is nothing you could have done.