Riding Dog as a specific familiar

[Rahveel]

Have a Player bringing a Gnome cleric into my game at level 6.

They went the Animal accomplice > familiar master route, and gave me a great character pitch I'd like to make work. Part of it involves a friendly dog companion.

As mentioned in the title, I'm thinking of letting them bring a riding dog in as a Specific familiar.

How many Familiar abilities would you price such a thing at in your game? I'm wavering between 4 to 6, but thought I'd see what others think.

thanks!