*edit - ninja'd!*
Guard Dog is an inate ability from Laris that only affects Kaya, providing several defensive buffs in close proximity to her.
Its part of the internal dichotomy of Kaya2, do you want Laris close to benefit from Guard Dog, or have Laris run farther upfield to arc dogpile or mussle or threaten a point to feat too. The answer of course, is both, and depends on the particular situation of the game.
Ghetorix is a beast with EKaya - P+S 23 and MAT 11 on the charge will finish just about anything, even a camping Campathrax (Venethrax) will take roughly 24 point of damge (assuming, primal, forced agression, free charge and 1 missed attack - for illustrative purposes only). The down side is no theme force.
The Winter Argus brings some anti-infantry, and an armour buff, which as pointed out, makes Kaya2 a very resilient 18/18 in combat or 16/16 + stealth to shooting, leaving her with a couple of tranfers, handy and some turns I have Kaya with fury to spare. There is some arguement as to whether extra transfers are preferable to extra Arm, but sometimes you need to dump/spend fury to take it off your beasts next turn, making yourself harder to kill is a good way to do this. The winter Argus is an ok option, its not the greatest beast in the world, but has its place with her, the duel sprays stack with a Beserk Stalker and Pureblood (spray/ghostly tramples) for anti-infantry and its a speed 7 slammer, it lacks the hitting power of the regular argus (combo-bite) though. Its also cheap enough to throw way for a good cause.
The Griffon fills a niche with EKaya's theme force of Solo hunter, its a good option for her.
None of these are released though, so expect people opinions to flesh out once they hit the shops, they'll certainly make me revisit Kaya2, and I won't be the only one, but they don't have as big an impact with her as other Dominion releases (Gallows Groves!) have with the other casters.