In principle, the owner of an animal is liable for damage caused by that animal even if he is not at fault for the animal's behaviour. Keeping an animal therefore entails a certain "strict liability". This liability is based on the unpredictability of the animal and its own energy, from which a lot of damage can result. Outsiders (third parties) are protected by this rule of strict liability.
There is a difference between the owner and the possessor. Sometimes these are not the same people. What matters is the person who has control over the animal. The difference between them is sometimes difficult to determine. We can tell you exactly how this works legally.