Is it possible to add visible traits to existing pets? If so how do you do it?

Im not sure if its just me who cant find it, or if it can only be done through breeding.

Thanks in advance!

adding traits to extant pets can be done but only within parameters

with extant pets, if they are Tamed, you can use a Mutator on them (four types: Lesser (random non-res trait into empty trait slot, may be either vis or carry), Greater (non-res vis trait of player's choosing to empty trait slot), Lovely (vis trait of player's choosing from specific list of traits, so some different pets have access to different ones), Lucky (same as Lovely, but different trait pool)

Generated, offspring, and Exclusive cannot have more Trait Points added.
Offrpring and Exclusive (and Tamed) can exchange what they have for something else Philter of trait disruption (themed) (gen1 themes only, random, will overwrite Restricted traits on a non-majestic theme), restricted trait philters, trait scrolls (both remove one visible trait (2tp). rtd replaces with a raindom trait from its pool into an empty trait slot, scroll replaces with its one specific trait)