Boy I am also sorry you lost a good one.
Here is a reminder everyone -- it is now getting to the point where most of us have some 30 day or so old calves running around. Remember that 30 day age frame -- THIS is where we start to see some problems with Clostridium infections.
The typically full of life - healthy playfull calf is normal and doing great in the evening or morning, and by the next morning or noon, you find him dead. No injuries, no scares, no trauma -- no reason!?
This is the reason more times than not. C-D is VERY VERY sneaky -- almost to the point where you have to almost be right there the first itme you see him acting funny, he'll be listless, meybe kick at his belly and lay down alot -- or get up and lay down repeatedly. They will almost always slosh when they walk, they sound like they are full of water.
Unless you find one of these soon, and get them treated with C-D Antitoxin quickly -- you will almost always lose them.
Again, the signs are quick to hit and may be subtle, but obvious of you know what to look for. Treat them FAST with at least 20 ml ORALLY, and 10-20 ml sub-q as well. I had one last year that we noticed almost unable to walk, he'd lay down, roll over - bellow - get up and do it again. Staggered when he walked. I ran right up on him and just held him down while the boy ran to the house for the C-D. I thought he was a gonner for sure.
I ran the full treatment, and witihin 20 minutes he was back nursing his bellowing mother. THAT was a close call. Incidently -- he was also the ONLY calf that did not get the mandatory dose of Alpha-7 at birth, I simply ran out. I don't run out any more. - Period.
This may not be what got your calf pard -- but I would almost bet you dinner it was! Was he full looking when you found him?? They will blow up really fast after wards too -- faster than normal.
Sorry for the preaching here, but C-D is deadly -- and if found soon, can be easily treated with very very good results. It is a crap game on the timing though, you just have to get lucky and see them soon enough some times or they are gone within a couple hours!
Even I can get complacent -- I try not to be , but it happens. 3 weeks to 60 days is the worst time for the calves it seems. I always booster mine at 30 days with the normal version Vision - 7 or 8. At least I know I did everything I could to help prevent the bug. Early wet spring?? Bad Clostridium year!
Best of luck from here on -- Terry