Ed Shacklee: Remedial Reading

 Dog biting man on ceramic plaque

  "BEWARE THE DOG," in black and white,
  unnoticed in a mental fog -
  the sign, translated, said I might
  beware the dog.

  Assuming on my morning jog
  its bark was bigger than its bite,
  I learned, while leaping like a frog,

  some Latin as I couldn't quite
  avoid the snappy dialog,
  what “CAVE CANEM” tells the bright -
  "BEWARE THE DOG."

Chained dog as in Pompeian mosaic Cave Canem