Both characters are great and I agree with the comments about the fur rendering but there is another difference and that is that the cat is more stylized with very distinct, sharp angles and geometry while the forms of the dog are all soft and flowing and not geometric at all except for the stylized nose.
Compare the tails of the cat and dog as just one example. Not only is the cat tail very stylized in shape but the striping just adds to that designed look. The dog tail has much less precision. The two heads also contrast in the same way with the cat head being mostly sharp triangles and again very strong color patterns. The shape of the dog's head is soft everywhere and is rendered in a single color. The bodies show the same contrast in approach as well.
I suspect that this is what you are seeing when you say that they don't live in the same universe. It might pay off to try bringing some sharper angles into the dog and to play with some geometric patterns in the coat.