While I get what you're saying, you would still be the person who is choosing to take offense in this situation, and getting yourself worked up. This would be more like if someone said you look like you're from Boston, weird because there's not a true 'look', but not a big deal at all.
Equating it to someone calling you a dog is the energy you're putting on it yourself. It's generally considered dehumanizing to equate gay people to dogs, something to consider