We had an issue with a 4-H calf this weekend. My son noticed the bloat late Friday morning. By the time I got home late afternoon, the 1200 lb. calf was really starting to labor on the breathing. We tried tubing the calf, but it kept chewing through the hose with his back teeth. We went through 4 chunks of hose trying to relieve the pressure.
A friend had some bloat treatment that they had gotten through Sullivans. While I traveled to pick up the bloat treatment, I had my son lead the calf around to keep him up. When I returned, we started to tie him up to give him the treatment and down went the calf. He was gone almost immediately. We tried tubing him, elevating him, but nothing worked.
I've learned a couple of things since then, but it was a hard lesson to learn. First, when tubing, it helps to have a piece of metal pipe or conduit that you should insert in the mouth to prevent the calf from chewing through the hose. Second, a last resort is to pierce the hide on the cow's left side where the bloat appears. The vet that came shortly after the calf went down had the tool, but the calf was already dead by then. A knife would have worked, but it can be difficult to work with and can be dangerous.
The steer belonged to a friend of ours, and we had been feeding it with ours since they always do better when not fed alone. It likely developed the bloat from wet grain or some moldy hay at the bottom of the hay feeder. We've been feeding limited amounts of grass hay, but the hay bunk will build up fines. The feed bunk is elevated and they generally clean it out very well after feeding. However, we have had significant rains lately and there have been a few times where they have been fed in the rain. It took less than 12 hours from the time that the bloat was noticed to the time the calf was gone. Sad day and a very expensive lesson to learn.