Curious what exactly it is about pet fur that prevents it from living on it but not plastic or cardboard?
Well, let's talk about that a bit...
There are actually three questions involved in this:
1) How long is the virus "alive" (meaning, it is viable and can infect a person) on the surface in question?
2) How long is the virus
detectable on the surface in question?
3) How well does the surface allow transfer of the virus to a human being?
For example, copper is a poor surface for covid-19 for both the first and second points - the metal is reactive, and that leads to quick chemical degradation in the presence of a moisture droplet.
Stainless steel and plastic are not reactive - so the virus lasts longer. But here, we should note that while they initially reported that the virus exists on stainless steel and plastic for days, that was about it being
detectable/ - fragments of viral RNS could be found. We should then note that the
half-life for the virus' existence on these surfaces is on the order of six hours or so. After just a few half-lives, while the virus is detectable by our measurements, the chances of someone getting infected from touching it has dropped significantly.
On cardboard, the virus lasts about a day - best explanation here is that the fibrous surface leeches moisture out of the droplets, drying them and allowing degradation on contact with air.
Animal fur may act a little like cardboard.
But, perhaps more importantly, animal fur may have the win on question (3). We should consider the structure of fur - which is basically hair. Fibers with tiny microscopic scales. Those scales likely hold onto tiny droplets or viral particles really well - better than the skin of your hand. So, in contact between fur and human skin... the viral particles are far more likely to stay on the fur.