[Nikko's_human]

I just recently bought Nikko some bully stix from the petstore but these are actually made from beef tendons and not penises. I don't know if they are much different but Nikko seems to like them. The only thing is that yesterday he seemed a bit constipated and when he finally went it was a hard little pebble and some stayed stuck to his tushy. I felt so bad for him that I gave him a warm bath and washed his tushy and he seemed happier. This morning he went like usual. Does anyone know if these things cause constipation?