Not all horses in the database were submitted by their owners. In the case where the horse is the Sire or Dam those are included but with limited information. In the future horses from pedigree tracing will be included where the result is an "educated guess".
None of the results here are guaranteed accurate and should not be used as such. Always get the actual result for the test from the owner that is verified against the registration data with AMHA. In the future when pedigree tracing horses are added they will be resulted with a "Suspected PSSM1" result and these should not be considered more than an educated guess.
As part of a future release I will be including "suspected pssm1" horses. These horses results are based upon tracing research and are nothing more than educated guessing and should be valued as such.