Is it just me or in some of the photos you're focused more on the background rather than the dog?
Granted this is an older pic from Oreo days on S9, but the focus here on the snout is better and have less of the fur issues others say about Samsung.
https://www.dropbox.com/s/xwoa2x1gyy...52919.jpg?dl=0
Pixel however does indeed have better AI and is thus better for point and shoot situations.
Samsung is more finicky and produces softer images on Auto and you need a steadier hand compared to when you're using a Pixel. You're better off with custom Pro settings or Sport mode when taking pictures of animals.
Here's a crop of the above pic and its sharper than the posted one of your dog when zoomed.
https://www.dropbox.com/s/a2ds5bu8bc...91209.jpg?dl=0
Maybe you could post links of uncompressed images?