Oh my, Kratos is really acting up
And here I thought my Sting was a terror at that age. You do have my sympathy. It seems to me that it is all excitement - especially that woing part and since quite understandably you find it difficult to cope with, he then gets carried away and works up the vocal scale to the growling. There are ways to cope with this. To understand his barking and to find ways to have him learn to be quiet, I suggest you may want to read (it is a short book) "Barking: the Sound of a language" by Turid Rugaas.