Max is a fictional dog name that appears in several popular movies and shows, so the answer depends on which Max you mean. In most cases, Max is portrayed as a mixed‑breed dog rather than a clearly defined purebred.

Common “Max” dogs

  • Max from How the Grinch Stole Christmas
    Often described as a small mixed‑breed “mutt” with traits resembling Beagle, Dachshund, and various terriers, rather than a single specific breed. In the live‑action film, the dog actor behind Max is generally regarded as a terrier‑type mix.
  • Max from The Secret Life of Pets
    This Max is typically identified as a small to medium companion dog modeled on a Jack Russell–type or similar terrier‑inspired mixed breed, rather than a formally named purebred.
  • Max from the film Max (the military dog movie)
    In that movie, Max is portrayed as a Belgian Malinois, a herding and working breed often used in police and military roles.
  • Famous real‑life dogs named Max
    There was a British therapy dog Max who was an English Springer Spaniel, and another Max recorded as a Beagle–Dachshund–terrier mix known for exceptional longevity.

Why there’s no single answer

  • “Max” is a very common dog name, so it can refer to many different individual dogs, each with its own breed or mix.
  • Many screen versions of Max are intentionally designed or cast as mixed‑breed dogs to emphasize an every‑dog, relatable companion look.

If you share which Max you’re asking about (for example, “Max from the Grinch” or “Max from The Secret Life of Pets”), a more precise breed description can be given.