Omarosa called Trump "A Dog" first.
"Omarosa Manigault Newman claims in a new book that there are tapes of President Donald Trump using racial slurs and that she saw him behaving “like a dog off the leash” at numerous events he attended without his wife, first lady Melania Trump."
https://www.apnews.com/500627912207463484d5856cb138bfc0
Trump simply responded in kind, as usual.