Beethoven is a family comedy centered around a mischievous yet lovable St. Bernard who brings chaos and heart to a suburban household. The film begins with a litter of St. Bernard puppies being stolen from a pet store by two bumbling dognappers working for Dr. Varnick, a sinister veterinarian conducting illegal animal experiments. One puppy escapes and finds his way to the Newton family‘s home.
The Newtons—dad George (Charles Grodin), mom Alice (Bonnie Hunt), and their three kids, Ryce, Ted, and Emily—are initially unsure about keeping the dog. George, in particular, is against it, fearing the mess and responsibility. But the kids immediately fall in love with the puppy and name him Beethoven after he barks along to a recording of the composer’s music.
Despite George’s reluctance, Beethoven becomes a permanent part of the family. As he grows, so do his antics: knocking over furniture, causing mayhem at barbecues, and interfering with George’s business meetings. But he also helps the children—giving Ryce the courage to talk to her crush, protecting Ted from bullies, and saving Emily from drowning in a pool.
Meanwhile, Dr. Varnick is still seeking dogs for his unethical experiments. When he discovers Beethoven, he tricks the Newtons into thinking the dog is dangerous by staging an attack during a vet visit. Against the family’s wishes, George reluctantly agrees to have Beethoven taken away.
However, George soon realizes the truth and discovers Dr. Varnick’s facility, where many dogs, including Beethoven, are being held in cages. In a dramatic rescue, George overcomes his fears and storms the facility, freeing Beethoven and the other dogs. With the help of his family and some of the previously freed animals, they expose Varnick’s operation, leading to his arrest.
In the end, George finally accepts Beethoven as a full member of the family. The film concludes with the Newtons embracing the joy—and occasional chaos—that comes with having a big-hearted, slobbery dog in their lives.