The UN, through the Committee on the Rights of the Child, the highest international body responsible for ensuring compliance with the Convention on the Rights of the Child makes a point to Portugal as this is the only country examined on Bullfighting, however, observation applies to all countries that are part of the United Nations. I believe this resolution it? a great part in the defense to the non humans animals and finished the Bullfighting in all the world:

Committee on the Rights of the Child 

Bullfighting 

37. The Committee is concerned about the physical and mental well-being of children involved in the training of bullfighting, and performances associated with it, as well as the mental and emotional well-being of child spectators who are exposed to the violence of bullfighting. 

38. The Committee, with a view to the eventual prohibition of the  participation of children in bullfighting, urges the State party to take the necessary legislative and administrative measures in order to protect all children involved in bullfighting training and performances, as well as in their capacity as spectators. This may include increasing the minimum age of 12 years for the training, including in bullfighting schools and private farms, and for participation of children in bullfighting, as well as increasing the minimum age of 6 years for children allowed to attend such events as spectators. The Committee also urges the State party to undertake awareness raising measures about the physical and mental violence associated with bullfighting and its impact on children.