Animal rights groups are alarmed over stray cats and dogs being culled in the Ukraine.
The move by Ukrainian authorities to "cleanse" the country of homeless animals before it co-hosts the European Football Championship in 2012 has led to cats and dogs being slaughtered en mass.
Images of the animals being shot or poisoned, rather than rehomed, were revealed by German investigators.
According to Ukrainian animal rights activists, the country uses a poison called ditilin that leads to irreversible paralysis of the muscles, preventing the animals from escaping and causing them a prolonged and agonising death.
In the capital of Kiev alone, it is estimated that as many as 20,000 animals have already been destroyed.
In the city of Donetsk, investigators from the German branch of the organisation People for the Ethical Treatment of Animals (PETA) discovered mass dog graves.
The Ukraine government is reportedly paying dog catchers the equivalent of £35 (€40) for each "disposed" animal, making dog killing a profitable business.
Although the government in Kiev said it would stop killing stray animals in early November, the practice is still occurring, according to Judith Pein, of the German branch of PETA.
"It would be cruel to do this anyway, but to do it for football is outrageous," she said.
"The people at these so-called shelters told us these were old and ill dogs, but there were puppies in there."
Many German footballers have now joined PETA Germany in publicly criticising the Ukrainian authorities for torturing these dogs and demanding that the city use humane methods to manage its homeless animal crisis.
"In an apparent effort to present the world with a glamorous image of its country during the June tournament, thousands of animals are being slaughtered by order of Ukrainian authorities," PETA UK manager Mimi Bekhechi said.
"These mass killings are directly related to Ukraine hosting Euro 2012.
"The world should know that while Ukraine is spending hundreds of millions of euros building new stadiums to host Euro 2012 matches, it is also spending huge sums of money ridding city streets of dogs and cats, often through unimaginably cruel and inhumane methods like poisoning or burning alive, causing animals to suffer prolonged and agonising deaths," Ms Bekhechi added.
PETA is appealing to the Ukrainian ambassador to the UK and politely urging him to stop these cruel killings immediately. To sign the petition, visit the PETA UK website.