In 1990, I adopted Wojo (cat) as a kitten from a rescue group. He was very alpha & very smart. The only pet for 9 years. In 1999 when I bought my cottage, I adopted Chelsea (dog--about age 4) from a rescue group. Chelsea was sweet and as it turned out later, a cat lover. When I brought her home for an afternoon trial basis, Wojo would not let us on the property. The rest is history. It took about two years before they could get as close as the first picture below. I used to say their names in the same sentence over and over very quietly helping them to make a connection. One of the noteworthy times in their friendship however was a surprise. I noticed increased bonding when they returned from the groomers. I talked to the gal at the groomers about this and it was nice that she was so observant. She told me what had happened. Wojo was in the tub in the cat section and Chelsea in the tub in the dog section. There was an open doorway between the two rooms. Wojo was meowing and not happy with the water. She brought Chelsea in next to Wojo to dry, and he settled down. When they came home, they were remarkably closer; and it was a big step to being buddies.
Wojo and Chelsea: This close is a miracle
Wojo & Chelsea: Imitation.
Now close became more common but still a miracle.