Ghouls that are feeded for a long time, as well as those that are frequently overdosed suffer a lesser version of the clan weakness. Here comes what Ghouls: Fatal Addiction tells:
A few clans' vitae possesses contagious properties. Ghouls imbibing/injecting five or more Blood Points from certain clans must make a Stamina roll (difficulty 5) or "inherit" a lesser form of the domitor's weakness; this last until the vita has been purged (i.e., the ghoul holds fewer than five Blood Points from one clan).
I think this contradicts a little other books where ghouls inherited weaknesses last more than that overdose. But I cannot recall which books. Note that it also tells that only some clans' vitae is contagious. Let's see the given examples:
The clans for which this rule most commonly applies are: Brujah (a ghoul "pumped" on Brujah blood frenzies at difficulties equal to those of a non-Brujah vampire[*]); Malkavaian (ghoul gains a mild Derangement); Nosferatu (Appearance drops by one or two points, but no lower than 1); Ventrue (ghouls gains a marked preference for Ventrue blood --possibly endangering the domitor); Setite(ghoul develops painful [-1 to Dice Pools] rashes when in direct sunlight; furthermore, many Setites have the Addictive Blood Merit); and any Sabbat (no mandatory effect, but remember the possibility of contracting disease via Vaulderie). At the Storyteller's discretion, vitae from other clans may cause similar effects.
[*] Note that overdosed ghouls already have increased frenzy rating, so you should adjust a little here.
Why those clans? I guess because they were the ones that they could thought better mild versions of the clan's weaknesses. Anyway, one can easily imagine a mild version of any weakness, and they left room to you for coming up with your own.
Note that there is a V20 Ghouls supplement coming, and I think we will see changes to these mechanics, and even a complete list of clans and weaknesses.
As a side note, I remember a funny conversation when people tried to imagine these weaknesses applying to animal ghouls (a Ventrue dog only wanting to eat some brand of food, a Tremere antitribu bird identified as Tremere antitribu by magic users, a Gangrel cat that gains other animals features, an Assamite panther that can no longer drink Kindred blood [or addicted to it],...).