I've been raising brown Chinese goslings (4 - 2 male, 2 female) for the first time. I estimate they were at least a week or two old when I purchased them and they were visibly thriving for about a month after taking them home. About one to two weeks after successfully moving them outside without a heating lamp, my goslings started dying under mysterious circumstances: (1) The dead gosling was found with his head hanging outside the bars of the dog cage in which the goslings were being kept. I'm open to the possibility of predation (i.e. a coon trying to drag him out of the cage) - however there were no physical marks. (2) The second dead gosling was found the very next day, just lying in the middle of the cage without any sign of external injury. (3) A day later, I found the larger of the two remaining goslings sitting atop the smaller one. The smaller one was very weak. I brought it indoors and put it under a heating lamp but it didn't survive through the day. (4) Now, more than a week after the deaths of the other goslings, I just discovered the remaining one in a very weak and unresponsive state. I checked on him early in the morning and he was very vocal with no signs of injury or odd behavior (feces, etc are normal). Just a few hours later, I found him laying sprawled out on his back. I've brought him inside and gave him a hot bath and he's currently under the lamp. He is so unresponsive I put his beak in the water to give him a drink but he initially couldn't even lift his head out of the water and was starting to drown. I don't think he will survive. Does anyone have any idea what could have caused this? A friend suggested botulism but I don't know where/how they could have all picked up that disease. I've raised chickens on another part of the property for years and they have never had health issues. I want to raise geese in the future, despite this initial failure - however I need to make sure there isn't something on the property that will lead to this same result. Thank you!