Maybe if one of those comments is made again, you could have some half-joking yet meant comment back. I certainly am not the most gifted person in tact (husband will verify this!), but there has got to be a way to have a comment ready to get your point across. Kind of, "yes another one - since I'm able to provide, I'm willing to save another. Small animal adopted, small dent in homeless pet population!"
Maybe they'll get the hint.
Actually, you should probably ask Ann "Wylie's Mom". She's the queen of wording things! - After I read my witty remark above; not so witty!