Normally, I'd say yes, but I'm not really happy with your description. Granted, talking dog has little history, but you didn't even bother to say he could talk. I believe I will permit you to RP as him for a trial period to see how it works.
If your posts are legible and contribute to the storyline, than sure, you can have him permanently.
As a hardcore game system modder, I have but one thing to say...
Throw away that RF sheilding, because:
Voiding Warranties is Fun.
I am the sleepless spirit that types messages to you in the dead of night...my frightening voice echoing through the net....waffles...WAAAAAFFFFLLLLLEESSS!!!!
-my pal, ssgokuu007