Is that supposed to make us feel better?
I'm saying from a Dogs point of view a kitten is a female, the word kitten itself is not an insult, it's us humans who made it into a derogatory term. The literal meaning of kitten is Female Dog. Like for me all female species, Human or otherwise is a female, so if I am reading in the point of view of a Dog I'd not be surprised reading the word kitten, because that would be what a female would be, that dog would not see it as an insult, it would just be it's word for a female. Like in Fanfic (maybe also in the manga), we often see Kurama call Naruto a Kit, because that's the term for a young fox.
Akamaru calling females kitten is not the issue, it's his view on women that could be the issue, because it doesn't seem to be too positive, something odd when you consider the leader of the pack is female.