Yes, you and Jeff are right, it could be offensive, but its all in how you play it. Its not about being militant and huffy- he just needs to express his own concern for the animals, and he can tell people point blank that he doesnt mean it offensively, its just how he does buisness. Then he can politely bring up what the animlas need, in brief, and see what their responses are... the seller can get a gauge of whether or not they will be cared for. And if you think people might be offended by that, Id have to disagree. Trust me, if you can tell the person you are about to buy from really CARES about the welfare of his animals, you wont be offended, you'll be a repeat customer.
I look for that in all the suppliers I buy from.
Only one perspective... don't sweat it too much!