A bunch of dogs are taken from a pet shop at the beginning of the movie. They are treated badly by the kidnappers.
An approximately 6-year-old child falls into a pool and nearly drowns.
The dog, Beethoven, knocks over a table, making two characters fall over. His leash gets tangled around their chairs, and then the dog takes off running, dragging the two people behind him.
There is a scene where Beethoven is lying on a married couple's bed, completely covered in mud and slime. When the dad walks in and yells at him, Beethoven stands up on the bed and shakes himself hard, getting mud and slime all over the dad, who is screaming.
A 10-year-old boy crashes a car through a building, with his two sisters in the back seat. (They are unharmed.) The car knocks over a table full of needles, and the needles literally pierce the "bad guy" in the movie, right in the stomach. He falls to the ground and closes his eyes, but it is seen later that he survives.
Four "junkyard" dobermans attack two more bad guys. The actual attack isn't seen, but we do see the two guys in bandages later.
A man puts fake blood all over his arm, then slaps Beethoven to provoke him. Beethoven gets upset and jumps on top of the man, but he does not hurt him. However, when the dog's family finds them and sees the fake blood, it appears that Beethoven seriously attacked the man. The dog is ordered to be destroyed. This was discussed in a few scenes prior, as well.
A little girl calls her father a "dog killer".