Uncle Sam. The Dog.

So here's something I'm working on maybe for work but I don't know yet. I have a things to say first:

I might use this image to promote a July sale on dog medicine. But do you think it's disrespectful to use Uncle Sam to sell dog medicine? I don't think it is because the "I Want You" poster has been parodied so many times, but I was just wondering what you thought, and if you think people might be offended. Because if it's at all offensive, it won't fly with my company.

And the other, more important thing is, does this image and it's potential use violate any sort of copyright law? Because I could see the legal team shooting this down if there are any copyright problems. I mean, if you parody a famous illustration, is that illegal? Or is it legal unless you're trying to sell something with someone else's concept? I don't know.

Do you?