bloat for dogs

Question
Hello, I am Katie and I am doing a report for my English class on bloat. The reason why I am doing it on bloat is because we wanted a Great Dane, but then found out we shouldn't get one due to bloat issues, so I just wanted to learn a little bit more, I have arranged a few questions for you to hopefully be able to answer for me.
My first question is; why does bloat usually happen in bigger dogs, and not usually in smaller dogs?

My second question is; how does it work, how does the stomach literally flip over itself?

My third question is; when does it happen specifically?

My forth question is; what causes bloat?

My fifth question is; what breeds are more susceptible to bloat?

That concludes the end of my bloat questions. I want to thank you for taking the time out of your day to help me with my English class report. Thank you
  sincerely, Katie

Answer
1) Deep chested dogs like Danes, Greyhounds, Dobies, Borzoi, German Shepherds, etc. are the most subject to bloat due to their conformation. Horses are also incredibly prone to it, but it is called colic.

2)Gas builds up in the stomach often due to a blockage in the intestines. due to the depth of the rib cage, the stomach is able to flip. This can be caused by the animal rolling due to the gas pains.

3) Already answered that.

4) Answered that too.

5) Bin there, done that :0)

Good luck on your report, Katie.  Hope I helped a little at least. Research colic in horses as well.  It will make your report seem more complete.

Sue