True & Honest Fan
All the evidence of pet contagion rests on one powderpuff doggo who was trapped inside with an ill owner for weeks. The dog's case seems to be mild. I think if people heed the Petco letter, wash hands and refrain from slobbering all over their pets the potential for infection is likely pretty low.
Even those doing testing on the dog seemed to feel that the positive hit on swabs from nose and mouth were so low level as to be almost certainly simply environmental contact, and not actually carrying the infection itself. In short the dog was probably licking it’s sick owner, and had traces of the virus on its nose and mouth. Not unlike you getting it on your hands. Pets cannot carry or host the virus. They can however be a mechanism for physical transfer. Especially within the same household.