How Cheap Dog Shampoo Ruins the Coat
Picturing the 3 layers of the fur (above), inexpensive, generic shampoos are abrasive with improper PH balance. Human products will also be just as bad as cheap canine products; even if they work great on human hair because a canine's needs are entirely different.
The ingredients in these will clean so harshly, that the outer layer of the fur strands with be damaged (and vulnerable to be utterly ruined the next time you bathe your Pomeranian) or will be stripped away that first time.
This leaves the hair essentially raw. It is then vulnerable to the sun, the wind, dry air, cold air, static, contact damage and split ends. Once damaged fur has a split end, it will run up the length of the shaft.