5 October 2016 Last updated at 13:16 BST
One of the main threats to these amazing animals is poaching for their ivory tusks.
Every year, tens of thousands of elephants are being killed in this way, with their tusks sold for a large amount of money.
To stop the criminals doing this, the authorities are using a number of tactics. One of these is using specially trained dogs to sniff out and stop poachers in their tracks.
Jenny went to meet some of these talented dogs and spoke to one of their handlers about just how they do it.
The number of elephants in the world is in decline.