There is a very interesting article published in the July issue of the Journal of Exotic Pet Medicine. It is (as far as I know) the first scientific study done on Spider morph ball pythons.
The article is far too in depth to include here but they did conclude that “Although further research is necessary for improved understanding, there is clear potential for significant welfare compromises to result from artificial breeding selection of reptiles.”
For those interested:
Rose, Mark P., BSc, MSc, CBiol, MSB, and David L. Williams, Ma, VetMD, PhD, CertVOphthal, CertWEL, FHEA, FSB, FRCVS. “Neurological Dysfunction in a Ball Python (Python Regius) Colour Morph and Implications for Welfare.” Journal of Exotic Pet Medicine 23.3 (2014): 234-39. Print.