[gemy]

A word or three-score about "when" health problems can show up.

CT - can show up in early puppyhood, or anytime there-after. Sometimes as a result of improper collar use, and or intubation during surgery.

LP - looseness at the knees can be seen at even 8wks old. Note I said looseness and not even calling it Grade 1. At this age puppy is too young to properly assess the knees. In Europe finally grading is done after 2yrs old - maybe even closer to 3yrs old.
Loose knees can resolve, with a)intelligent exercises and b) safe practices of which there are many and c) joint supplements. And or some combination of both.
A book can be written about the exercises and the safe practices.

LIVER sHUNT LS: Can show up in a young puppy - recommended BATS testing at 16wks and 6months. Can show up later on in life, secondary to some other problem - for example bladder stones.

Hyperuricosuria - another condition that is genetic and can show up and often doesn't show up until after 5 years old (males predisposed to more serious concerns here).

Thyroid problems - May not show up in early life prior to one year old, and may show up after de-sexing, 2-3-4-5 years later.

Allergy problems: Do not usually show up until after one year old

PRA and or Cataracts - Can show up anytime up to 6 yrs old.

And the list goes on.

SO OP: at 15 wks old your puppy is healthy so far. Until you reach at least mile marker of 5 years old, you won't really know for sure.