Kick me when I'm down...

I received a call today from Jim, where Ris has lived since Nov. 23. Unbelievably he was calling to tell me Ris died this morning. The same way that Bam did, in his sleep! What? I could not believe him. What on earth would cause two young sheep to die within 24 hours of each other? Bam and Ris both came from Sabrina, but are not related. Bam was born on April 15, 2008, and Ris 15 days later. Neither showed any signs of any issues.
Jim has much more sheep experience than I do, and his only thought was liver flukes. The only problem with that hypothesis is that Bam and Ris were never in the lower pastures that border the river. All of the other sheep were in those pastures this summer and into the fall, but Bam and Ris were not. They were in the lawn and areas close to the house, no access to the river. Jim was delivering Ris to the vet tonight to be posted. I talked to the vet and he said he will call if he wants us to bring Bam over also. When we asked what would cause the two of them to die within 24 hours of each other when they have been on farms 30 miles apart for the last two months his response was fate. Not exactly what I wanted to hear. Right now I'm just praying it is something that will not effect any of the ewes.