In SS003, Growlithe assisted Officer Jenny as she was holding traffic for a group of Ivysaur to cross the road.
Personality and characteristics
Growlithe as a puppy
Growlithe was shown to be very loyal towards each Officer Jenny, as shown in their debut episode when one of the Growlithe was a puppy in a flashback.
Although Growlithe remains the "signature Pokémon" of many Officer Jennys, they will sometimes use different Pokémon. The Officer Jenny in Mutiny in the Bounty! used Growlithe's evolved form, Arcanine. In some parts of the Pokémon world, police forces will have special Pokémon teams, such as Spinarak in Spinarak Attack.
The Officer Jennys of Unova and Kalos do not use Growlithe, as they are not generally found in those regions. In Unova, the most common Pokémon Officer Jennys use are Herdier, and in Kalos, Manectric.