Here's why:
* Abstract nouns represent concepts, ideas, qualities, or states of being that cannot be physically touched. Examples include happiness, freedom, love, justice.
* Concrete nouns represent physical things that can be touched, seen, smelled, heard, or tasted.
In this case, "Word" is a proper noun because it is the name of a specific sheep. Proper nouns are always capitalized.
Therefore, "Word" in this context refers to a tangible, individual animal and is not an abstract noun.