The greatness of a nation can be judged...

"The greatness of a nation can be judged by the way its animals are treated."
- Gandhi

First of all, most nations cannot be judged as a whole because of the diversity among their people. Disregarding that, it makes sense that a nation that immorally treats animals is very likely to show immorality regarding other things as well...but that is not an absolute.

A nation could love animals, treat them well, even worship them but still be a horrible society. For example, they could be treating animals highly but look on women as nothing more than slaves. Or they could worship animals but actively partake in bloody human sacrifices.
The opposite could also be true: a society that treats animals horribly but is perfect in all other ways.

What this boils down to is that improper animal treatment can reflect evil within a society but a society's greatness cannot be judged entirely on how it treats animals.