Love is something reserved almost exclusively for humans.
If Eclipse were ever to be accused of feeling more for his lord than would be approved of, he wouldn't think of Raenef's misguided determination and eagerness to please him, or the way he would lie with his head in Eclipse's lap as though waiting to be petted, or the pleasure he took in Eclipse's company. He would think of Raenef looking at him curiously, and asking "So, you've got to do anything I tell you?"
It wasn't likely, certainly, but Eclipse had learned never to rule anything out when it came to Raenef, even things that common sense would mark as impossible.
Besides, it was the only explanation that Eclipse could think of that didn't make him fear for his sanity.