why Sirius transforms into a dog

[magicalme9]

No: HPFGUIDX 64308

--- In HPforGrownups at yahoogroups.com, "maneelyfh" <maneelyfh at y...> 
wrote:
> I realize this is probably been discussed before, and I have tried 
to 
> serach the archives.  But dogs do not seem to be wizard animals so 
> why is Sirius's animagi a dog?  
> 
> fhm

I've given thought to the whole animagi theory, too, but am not able 
to come up with sraight answers. IMHO wizards and witches transform 
into the animagus form that goes best with their character. Don't 
know whether they are able to choose the animal. Now, Sirius is to me 
(besides all the other awesome things:)) a very loyal person. Dogs 
are known to be very loyal friends, they always follow their masters 
no matter what. (Sirius doesn't seem like the person to take orders 
from a master though...although he follows DD orders not to leave the 
house). 
As to dogs not being a wizard animal, well beetles or stags aren't 
either...

magicalme (who hopes this has helped a bit)