I wouldn’t trust the health of my animals to SmartThings. It’s just not reliable enough. In Fact, the official product usage guidelines say the same thing:
That said, you can see what some other people have done by using the quick browse lists in the community – created wiki and looking under pets or animals:
And while it doesn’t solve the problem of SmartThings reliability, you could consider The $34 Kumo wireless tags, which have a high degree of accuracy, a wide range of environmental tolerance, and you could set up a dual reporting system through both IFTTT ( they have their own IFTTT channel) and SmartThings. You have to buy their $39 Ethernet bridge as well (one Bridge supports about three dozen tags) so the whole thing may end up being too expensive for your needs, but it’s worth knowing about. And I think it would be a little more practical solution for your particular use case then the netatmo, if only because of the size.