Assessing Pubic Symphysis Evolution in Guinea Pigs ( <i>Cavia porcellus</i> ): Insights From Computer Tomography on Primiparous and Non‐Breeding Females

In guinea pigs (Cavia porcellus), dystocia is a common occurrence. Several factors have been identified in the literature, including the ossification of the pubic symphysis following failure to breed before 9-12 months of age. The objective of this study was to investigate the ossification of pubic symphysis and its evolution during growth in two groups of females. The first group consisted of non-breeding females, while the second group comprised females introduced to breeding at 4-6 months of age. Twelve pairs of sows were selected for comparison, with one non-breeding and one breeding sow in each pair. Symphysis width and tissue density were assessed using micro-computed tomography. Measurements included the distance between the acetabula, width and bone density of the pubic symphysis. Serial computed tomography scans were performed on each sow over several months, both before and after parturition. The results revealed a significantly higher symphysis width in females that had bred. In addition, symphysis ossification was absent in both breeding and non-breeding sows, contrary to previous descriptions of this species. Therefore, dystocia in guinea pigs may not be attributable to ossification of the pubic symphysis.