In a very different sense, I've also been immersed in another language for as long as I've worked with animals: Latin. However, I don't speak Latin. Couldn't conjugate a verb to save my life. Still, it's hard not to pick up a little when you are around animals. Let me explain...
See? Even he is having a hard time with his Latin... and that was back when people actually spoke it!
Why have Latin names - just to make us look smart, show that we earned that college degree that earns us the right to shovel poop at minimum wage for a living? Latin names serve an actual purpose. For one thing, they help reduce confusion about identifying animals, especially between folks from various parts of the world. A lion may be "lion" in English, but it is "leon" in Spanish, "simba" in Swahili (or Disney), or "sinha" in Hindi. Scientists in the US, Spain, Tanzania, and India might not know the common name in each others tongues, but all will understand Panthera leo. Conversely, common names may be used in different places to refer to different animals: Asians and Latin Americans may both refer to their big jungle cats as "tigers", but Latin names help differentiate between the actual tiger (Panthera tigris) and the jaguar (Panthera onca).
Differences may exist in names within a single country. Here in the United States, if you show ten people the same picture of a large, tawny native feline and ask them to identify it, you may get half a dozen names: puma, mountain lion, cougar, panther, catamount and more, all in common use somewhere or other. The animal is still Puma concolor.
Puma concolor - a cat of many names
Zoos utilize Latin names to varying degrees. Mammal keepers tend not to use them too much, at least not it day-to-day usage; everyone knows what a giraffe is, after all. They will use them, however, for official paperwork and record-keeping. Bird folks use them more, reptile and amphibian people use them a lot, and fish and invertebrate people might use them exclusively. It makes sense - reptile and amphibian common names are often descriptive and (to be honest) unimaginative, so the Latin names are more descriptive and accurate (there's over 10,000 species of bird - you try coming up with a memorable name for each one). Plenty of species don't even have common names, only Latin ones.
I trip over Latin names plenty of times. For one thing, I almost always see them written and rarely hear them spoken, so I'm never sure on the correct pronunciation. Also, the names tend to change: species are lumped together, or (as is more common) broken up into more species, or names are reworked to change our understanding of how species are related. It's confusing, and can be hard to keep track of. It is essential, however, for keepers and aquarists to keep up on scientific nomenclature in order to communicate with their colleagues at home and around the world.
And besides, how awesome is that, being able to say you're a (sort of) Latin-speaking zookeeper?
What's that? I mentioned earlier that some Latin names are three words? Well, that third one is the subspecies... and that is a whole 'nother can of worms...