Countries have the power to make plants/animals immortal, just like them. Don't ask why or how, it just happens lmaoo
And for some reason this doesn't work on humans, again, don't ask why
Here's a list of some of the pets of countries:
Britain - A black horse named Goldmary, who was gifted to him by England in the 1600's. Also a Corgi who was given to him by the Queen who doesn't have a name yet
France - A siamese cat named Cécile, who she purchased in the 1800's after somebody had brought the breed over from Thailand
Japan - A Shiba Inu dog, a black cat, and a koi fish who at the moment are all unnamed xD
Germany - A Doberman named Rex who was a gift from America after WWII. Rex was also a retired military dog
Mexico - A snake named Sol who she found in the streets of Mexico City and casually snatched and took home