IMO, don't ever not take a photo because the light or some other aspect is not perfect. It is better to have an image with less than great lighting than to not have the image at all.
Your pictures show Kushan as he is; a big beautiful dog on his way between puppyhood and being an adult, For many dogs, people too, this is an awkward time but, Kushan is really developing into a beautiful boy.
You simply cannot have too many images of your dogs. I look back on images of dogs that I have shared my life with who are no longer with me and these images keep the bond alive. Here is one of my first digital images of my Sara Lee, shot with a Canon 10D and a kit lens in 2004. Sara was an 85-pound Golden Retriever - German Shepherd - Wolf mixture. I have a framed print of this hanging in my hallway and there is not a day that goes past without my thinking of her. She died 12-years ago from cancer.
The image right shadows on her face were a bit dark so I used the camera's pop-up flash to balance out the light a bit...
I think that was the only time I ever used the pop up flash...