MRI evaluation of spontaneous intervertebral disc degeneration in the alpaca cervical spine. - Stolworthy DK; Bowden AE; Roeder BL; Robinson TF; Holland JG; Christensen SL; Beatty AM; Bridgewater LC; Eggett DL; Wendel JD; Stieger-Vanegas SM; Taylor MD (Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2015)