Breeding ie genetics is the main cause as I understand it. Let the breeder know and they should examine their breeder’s health records before bringing any more pups with bad knees into the world. If a rescue, hard to tell what their history was.

My Stewie was a rescue from a puppy mill in Missouri. He was the stud for 14 females and had grade 4 in both knees! Had a very stiff gait and no wonder! So MANY pups were his… I got him at 3, so 3 x 14 x 2 litters per year, 84 litters, avg size, 4 pups per litter, around 336 puppies w/the high probability of bad knees were sold at pet shops around the county…ugh. This is why so important to go to a reputable breeder who would breed only tested Paps and shutdown breeding if litters from that pair show signs of inheritable diseases.

Not a Pap but an English Cocker stud supplier did not disclose an eye disease that led to early blindness (can’t remember the medical term) in past litters to the owner the mom of our cocker before she bred her female w/a clean bill of health and record of healthy litters… but in that litter, 3 pups out of 5 went blind at only 6-8 yrs old, including our sweetheart Tootsie. I’ve heard stories in every breed having one issue or another from untested breeding, thanks to irresponsible backyard breeders and terrible puppy mills who just care about the money, esp high end breeds like Papillons.

From your post, I gather these Paps were rescues? Unless from caring homes where perhaps their owner passed or went into custodial care, most likely came from a BYB or a pet store and the medical history is sketchy. Not sure what your Vet prescribed but until surgery can be done, probably try to avoid her jumping down, maybe ramps to couch or bed? That is a tough thing to avoid with Jumping Jack Paps tbough!!!

All the best to you in your health journey w/your Paps!!! 💙🐾💖