Papillons shed their hair twice/year.
The Papillon being a "single coat" (no under-coat) dog , and with regular brushing, you can avoid most of the white hair on your clothes, couch and other.
A Papillon under stress may loose hair, a lot of hair! Right down to the puppy look between 4 and 7 months.Stress can be initiated by:
Bitches post whelping.
Health problems.
Insufficient diet.
There are many more reasons, why a Papillon can be stressed out, but these above are common ones.
Here is our Gina as a 15 months old girl with a full healthy coat. Above is our Matti : one months post whelping. And that hair-loss on her has gone to the worth since December 09.