In Aesop's fable "The Wolf and the Dog," the wolf thought it was not wise to attack the house dog because the dog was:

• Well-fed: The wolf saw that the dog was plump and in good condition, indicating that it was well-cared for and not desperate for food.
• Strong and Healthy: This suggested that the dog would be a formidable opponent.
• Guarded: The dog's collar indicated it had an owner. Attacking it would bring the owner's wrath, which was something to avoid.

The wolf, being lean and hungry, realized that the risk of fighting a well-fed and guarded dog outweighed the potential reward of a meal. It was safer to look elsewhere for easier prey.