I seem to recall them walking back the conclusion that dogs do not transmit well, but don't have the reference at hand. I wonder if they were actually mistaken at first, or if the virus has simply evolved in the direction of being better transmitted by dogs?

I wouldn't be surprised if they end up concluding that pigs can catch and transmit as well, eventually. Birds does seem to be more likely to hold true, as I don't know of any non-mammals that have been found susceptible yet.

I dunno what you're on about, dogs do not realistically transmit covid. Their respiratory system is more different to humans than a cat's. Ferrets and other animals with extremely similar respiratory systems are known reservoirs and have already been culled in some countries.