Hello,

Sadly last night my bunny Fred passed away.

In the morning, I sat on the floor to pet him, but he didn’t run to my like he often does. I put him in my lap, and he seemed a bit lighter and weak, but it didn’t concern me too much (in bind sight it should have). I went to work at 2, and when I went to go to bed around midnight, I found him laying on the floor, limp, unable to sit up. This is when I really noticed his weight loss. He was breathing pretty calm, maybe a bit fast. I knew he could die at any time, so I decided to make him comfortable rather than take him to the emergency vet and stress him out more. He wouldn’t drink any water and was pretty unresponsive. He occasionally would twitch almost like a seizure. He died a little while later.

He would often walk under my feet or sit right by the door and get hit by it when I opened it, usually not too hard, but I know they are more fragile than we realize.

Another thing is the hay I had been feeding my bunnies had water at the bottom (I replaced the hay once I realized this) and was moldy/mildewy (which I found out after he died). I am inclined to believe it was the hay, but my other bunny seems to be doing fine even though she had eaten the same hay.
Based on the symptoms and circumstances, Do you think this was caused by an injury I was unaware of or the hay?
I know only an autopsy will give a definite answer but I thought maybe someone might have an idea.