Let me just tell you that bloat is my biggest fear as a dog owner.
Bloat might not seem like a big deal to humans, but it can be deadly to large or deep-chested dogs. An emergency vet explained me that a dog's stomach hangs like a hammock, and when a large amount of gas is sitting in the abdomen it can cause the entire stomach to twist. When this happens, the blood and oxygen supply is cut off and dogs can die within minutes. Unfortunately, many people don't take their dogs to the vet until the stomach has already flipped and it's too late. I wrote about some tips and signs to look for since I went through this scare with Boomer a few months ago.
No one really knows the exact causes, but we have somewhat of an idea on what triggers it. We know it mainly happens in large dogs, especially those with deep chests like Great Danes. We also know it can happen if your dog drinks too much water too quickly. It can also happen if you feed your dog foods with ingredients like citric acid and add water. Intense exercise too soon before or after a meal may also cause it. I avoid all of these scenarios to prevent it, just in case.
How to prevent it
Sadly, you can never truly prevent bloat, I learned that from my experience with Boomer. But, you should monitor your dog's water intake as much as possible. Read your dog food ingredient list and make sure there are no citric acids if you normally like to add water to the food. This causes strong acids in the stomach that create gas. Most importantly, never feed your dog 1 or 2 hours before or after exercising them.
In the very beginning stages, your dog's stomach may make loud gurgling noises, like a human's stomach when you're hungry. I could hear Boomer's stomach from across the room. At this point, give your pup some Gas X pills (3 - 4 pills should work, they can't overdose on these), and take them on a long, but slow, walk to encourage the gas to travel out of the stomach. Do this about every half hour for several hours. We had to do this once for Boomer after he got x-rays and his stomach (luckily) did not flip, every time he burped or farted I was so relieved lol!
*If your dog starts retching, or looking like he's trying to vomit but nothing comes out, IMMEDIATELY take him to the vet - preferably a hospital so they can do surgery, if necessary. Also take them if they look uncomfortable or are pacing. At this point the vet will want to take x-rays to see if the stomach has flipped and if surgery is needed.
Once the stomach flips, it swells like a balloon because of the trapped gasses. These photos aren't pretty, but I want to make sure you have a visual of what the symptoms look like. I kept thinking Boomer's stomach look bloated, but the vet said it did not and that it would look like he swallowed a watermelon if it was. If you haven't taken your dog to the vet by this point, you must go when their stomach is visibly enlarged like this!