This is true. I tend to say my familiar (bat) catches bugs and other small critters during our travels, but now that you mention it, no one has fed our horses in about a year....
On a lighter note, when I made up my character oh so long ago, I must have thought it would be fun to select "chicken" from the list of items she could carry. Well, I forgot about the poor thing after the second game and only recently rediscovered it on my list of belongings. I asked about it, and the DM told me, have you been feeding it? I answered honestly, and it was determined that said chicken probably died a cruel and terrible death ages ago. I felt awful. I really did.