"Old school" Hollywood did not expose dogs in movies and movie's posters. That became the tendency of recent 20 years.
Question: How many movies are there about the composer Beethoven?
Answer: 3 (three).
Q: How many movies are there about dog "Beethoven"?
A: 8 (eight).
If you take a closer look at life of talented actors who are doggists, you can easily find that bad karma of doggism hits them badly, even most talented and most beautiful.
Everybody does know about troubles of personal life of Paris Hilton.
Here some other examples:
Here about Jessica Alba