People who campaign for animal rights say the way some animals are taken thousands of miles to be slaughtered is cruel and unnecessary.
They have released undercover filming which they hope will help persuade governments across the world to ban it.
Campaigners say every year tens of thousands of animals die being transported, and they should be killed nearer the places they are reared.
But they say very few animals are
exported either into, or out of the UK.
The majority of animals that you see in lorries in the UK are travelling shorter distances, and in better conditions.
Leading animal welfare charities, including the RSPCA, are taking part in the world-wide campaign called Handle With Care.
They say many animals suffer crowded and filthy conditions, and some die from disease, hunger and stress on the long journeys.
They claim horses are being trucked from Spain to Italy on journeys lasting up to 36 hours, and four million sheep a year are shipped between Australia and the Middle East.
Leah Garces, from the World Society for the Protection of Animals, said: "We were determined to show people the truth of this hidden and brutal traffic in animals: if you see it for yourself, you just know it must be stopped."