Horse owners are becoming increasingly concerned over the development, TV4 reported.
According to the Swedish Veterinary Association (Veterinärförbundet) there were around 20 reported cases of horses or cows with their sexual organs mutilated reported in 2006. By 2010 this number had doubled to 40 cases.
"Our understanding is that it has unfortunately increased," said Johan Beck-Friis at the association told TV4.
TV4 figures compiled with the help of the police indicate that the problem could be even worse with 60 reports of the genital mutilation of horses have been filed in the areas around Sweden's major cities alone.
Niklas Långström, sex crimes expert and professor of psychiatric epidemiology at Karolinska Institutet, told TV4 that this is not a case of ordinary cruelty to animals.
“This is done by people getting a sexual kick from animals in general and of inflicting pain on them, a sexual sadistic kick, so to speak,“ he said.
According to TV 4, only two weeks ago the mare Bionne, Swedish jumping champion in 2009, was mutilated. She is currently pregnant by Tornesch, Swedish riding star Malin Baryard-Johnsson's stallion.