Loyal is a pet trait featured in The Sims 3: Pets and The Sims 4: Cats & Dogs. The trait is only available for dogs in both games.
The Sims 3: Pets[]

"A dog is a Sim's best friend" is a saying that certainly holds true! Loyal dogs love spending time and interacting with their Sims, and even seem to learn skills faster than other dogs.
Attributes[]
- Dogs will tend to follow around the Sims with whom they have the highest relationship.
- Dogs will learn skills more quickly.
- Dogs will build relationships with family members more quickly.
- Dogs will accept social interactions with Sims more often.
- Dogs with this trait are very effective against burglars.
- In The Sims 3: Supernatural, Loyal dogs will growl at invading zombies.
- In The Sims 3 Pets (console), Loyal dogs will never run away from fire and will guide Sims away from it.[confirmation needed]
Loyal pets[]
Walter Blackburn, Shep Fox, Ralston Schmidt
The Sims 4: Cats & Dogs[]

Loyal conflicts with the Independent trait. Cats have a similar trait called Affectionate.
These dogs want to be closer with their owners and love to be pet. They like to follow their owners around.
Attributes[]
- Dogs gain more social motive when pet.
- Dogs prefer staying near their owner and may search the house for them.
- Dogs are more likely to sleep close to their owner rather than sleep on their own in a pet bed.
- The "Heel" command does not need to be taught to a loyal dog, it is automatically learned.
- Increased satisfaction points are given to a Sim when the "Feel the Love" interaction is done with a loyal dog.