help I found a tiny work like thing and it killed my new Den cane

[let_it_grow]

I went to check on my chids and saw one of my dens new canes had a black rotten ring about half way up. I felt the bottm of the cane and it was mushy so I sterilized a sharp knife and cut it off then put peroxde on the cut. I wanted to see what was going on so I sliced the cane lengthwise and saw the base was soft rotten and had a bit of mold on it. Taking a close look at the area that was still green and firm I saw a teeny tiny clear worm like thing. The only reason I saw it was cause there was a black line (I'm guessing it was the food in the organs) and I saw it move. As odd as this sounds the rotten cane smelled like beggin strips (yes the treats given to dogs). I looked over the rest of the canes and I see no signs of any critters. Does anyone know what this could be?