Mean ± SD fold increase in gene expression of ADAMTS-4 in healthy and laminitic equine digital laminae. The RNA was extracted from 3 sections of dorsal lamina obtained from 8 healthy control horses (CON), 6 horses during development of laminitis that corresponded to onset of fever (rectal temperature ≥ 38.9°C), 6 horses at onset of Obel grade 1 lameness (OG1), and 5 horses at onset of Obel grade 3 lameness (OG3) and reverse transcribed into cDNA. An RT-qPCR assay was performed in triplicate for each cDNA preparation with optimized gene-specific primers to analyze gene expression of ADAMTS-4 normalized on the basis of gene expression for GAPDH in corresponding samples. For each gene, primers were selected so that they did not amplify genomic DNA. *Value differs significantly (P < 0.05), compared with the value for the control horses, as determined from 95% confidence intervals of the treated samples via a 1-way ANOVA.