Is it offensive when using the word 'animals' (in this context)?

I have read this question on Travel.SE, and I am kinda confused about the use of the word animals in that question:

These are entirely different classes of travel. Portugal+Spain is an easy trip within the usual Western world, close to home and without any significant apparent dangers other than the usual pickpockets and the expensive Euro zone. You can easily get home if needed (regular flights from Madrid and Barcelona directly to TLV, connections through all around Europe from everywhere else).

Russia, Cuba and China are different kinds of animals.

Russia is an unstable place, other than in......etc

Was it meant to be offensive or not? if not what did he mean?

No, not at all. In fact, the phrase "a whole different animal" can be used idiomatically to mean "another category altogether."

Here's an example where an airline is using the phrase to promote itself in a positive light:

Let's face it. Air travel is a pretty straightforward business. You need to go someplace; we'll take you there on one of our planes.

But that's not what we're all about. Our tagline "A whole different animal" means we approach our business with four key principles in mind. These are the four legs that we stand on. They're who we are. "A whole different animal" represents our promise to you. Simply put, our goal is to do the little things that make a big difference to you. We're affordable; we're flexible; we're accommodating; we're comfortable.

In the example you cite, the writer is simply saying that traveling to Russia, Cuba, and China would be very different for the tourist than travel to those other destinations. For the adventuresome traveler, this might be considered a plus. For those who want easy, hassle-free travel, however, it might be best to avoid these destinations.