The objective of this study was to investigate the distribution pattern of two different volumes of a mepivacaine 2%/iopromide mixture along the infraorbital nerve using a controlled injection pressure. Infraorbital nerve blocks were performed at the infraorbital foramen with two different volumes (group 10: 10 mL or group 15: 15 mL) using a 22 gauge, 3 cm long needle and a standardised injection pressure in 10 cadaver skulls. Ten minutes after injection, computed tomography was performed in all skulls. Images were analysed for needle position, length of the iopromide column, filling percentage of the infraorbital canal, presence of iopromide at the maxillary foramen, volume of leakage, length and angle of the infraorbital canal and pathological changes. Percentage of infraorbital canal filling ranged from 74% ± 0.23 to 86.9% ± 0.24 and iopromide was present at the maxillary foramen in 70–90% of the blocks of groups 15 and 10 respectively; neither variables differed significantly between groups 15 and 10 (P = 0.582 and P = 0.244 respectively). Mean leakage retrograde into the rostrally surrounding tissue and into the maxillary sinus was significantly greater in group 15 (7.9 cm3 ± 4.2) than group 10 (3.02 cm3 ± 3.13), P = 0.008. Older horses were significantly associated with higher filling percentages (P = 0.049), whereas filling percentages or whether the mixture reached the maxillary foramen were not associated with any of the other variables. Infraorbital nerve blocks using 10 and 15 mL result in complete filling of the infraorbital canal in the majority of horses. This block may result in sufficient analgesia of Triadans 06 to 11 and offer a suitable safe alternative to maxillary nerve blocks.