Scientists just recently found a new coronavirus that is associated with dogs, in human pneumonia patients. Samples were taken from 301 patients in Malaysia that were treated for pneumonia and 8 were found to have this novel coronavirus. This has never been reported before. It is not known how these people were infected, but equatorial areas, with high biodiversity, where humans are in close proximity to other animals, can set the stage for these events.
Scientists think these cross-over events (jumping from one species to another) could be occurring more often than we think. People are screened for human coronaviruses, not non-human coronaviruses. There are now 8 coronaviruses known to infect humans.
Although this canine coronavirus was found in humans, there is no evidence at this point of human to human transmission. But it is being considered a possible threat for a pandemic. Spillover events take years to develop and encompass multiple different steps before they infect humans.
Two recent studies point to the importance of coronavirus vaccines for domesticated animals.