Vegi...
For what it's worth, and understanding the term roommate to refer to an equal partner, or at least another paying partner, on a lease/rental agreement (lawyer in me tehee), you have every right to request there be no dogs. Especially, if as you so eloquently phrase it, you are somewhat known not to be a fan of the canine species. This shouldn't even have been an issue.
That' said,
again.... The things we go through with roommates... sheesh.
And I'm a dog lover. Same opinion.
-TB.