Female puppy's urine sometimes has slimy texture

My parents have just recently bought a new puppy, and all of us are inexperienced, so I'm not sure what I should do.
When she was no longer croutching down after peeing, I saw that it was this sort of slimy substance, so I patted her dry. The next time however, her urine seemed normal. This has happened twice this week, but all other times her urine is normal. What's going on?

What does your puppy's stool look like? How old is your puppy? What are you feeding her? What type of pup is she? The more information you give us the easier it will be to help you