Dogs cry if they have been hurt, are hungry or neglected.
If you mean wet marks from the inside of their eyes some dogs will get this and it's just fluid (it cleans the eye of dirt) running down each side of the dogs nose. If the dog is whining, yowling then it's doing so because it's in pain so see a vet IMMEDIATELY! If the dog is whimpering they may not be feeling well; could have a tummy ache; may have something stuck in the pad of one of their paws, have ear infection or simply want to go for a walk. You should get to know your dog's habits. If you have no idea what is going on then seeing a vet is a good preventative measure for good health for your pet.
Puppies are like other babies, they cry because they want attention or either they are hungry. They want to know that they are safe and they want to be with their mommy.
One reason is separation anxiety. Here's how it looks like and how to prevent the problem,
http://dogtime.com/separation-anxiety.html
When Dogs Cry was created in 2001.
When Dogs Cry has 250 pages.
This noise hurts the dogs ears and makes them uncomfortable, so they cry out.
some dogs can but other dogs can not
yes.
they cry when they are unhappy a-or sad
When dogs are sad they do not cry, like we do. And I'm not sure why you would want to know how to make your dog cry.
While dogs are not known to shed tears when in pain or feeling sadness, new studies show that dogs can actually shed tears of joy. This is most prevalent when being reunited with their owners after an extended period away.
Bark
A Howl or Howling.
The reason dogs cry when they laugh is because their so excited that they just wanna cry.
Of course not!