The threat rhinos face from poachers in some parts of Africa and Asia is now spreading to the UK.
Rhinos face serious danger from people wanting their horns - often to use for medical reasons.
It's such a big problem that last year in South Africa 450 rhinos were killed.
And now zoos and wildlife parks in Britain have been told to be on high alert in case their rhinos are targeted by poachers too.
Ricky's been to Colchester Zoo in Essex to get the story...