The association between bloodwork, signalment, and urolithiasis in guinea pigs (Cavia porcellus)

Urolithiasis represents a common, potentially life-threatening condition in pet guinea pigs (Cavia porcellus). The purpose of this study is to determine the potential association between signalment, packed cell volume, total solids, selected biochemical parameters, and imaging evidence of urolithiasis in client-owned guinea pigs presented to two veterinary teaching hospitals. Medical record databases from two veterinary teaching hospitals were searched for cases of client-owned guinea pigs that had both a plasma biochemistry panel and an imaging study performed during one medical event. Other parameters including age, sex, weight, packed cell volume, and total solids were also recorded. Of the 81 guinea pigs that met the inclusion criteria, 32 animals (40%) had evidence of urolithiasis present on at least one of their imaging modalities. The odds for the imaging presence of urolithiasis increased with a decreasing packed cell volume, an increasing plasma creatinine concentration, and with a decreasing plasma phosphorus concentration. While these variables were statistically significant and associated with imaging presence of urolithiasis, they had low predictive value to discriminate between guinea pigs with and without imaging evidence of urolithiasis. Given the relatively high prevalence of urolithiasis in guinea pigs in this study, imaging is strongly recommended for every animal with suspected affliction.