Abdominal ultrasound features and reference values in healthy guinea pigs (Cavia porcellus)

Background: This study aimed to determine the ultrasonographic features and reference values of the abdominal anatomy in guinea pigs.Methods: A complete abdominal ultrasonographic examination was performed in 20 adults and 20 young guinea pigs. The thickness of the wall of the gallbladder, stomach, duodenum, caecum, colon and urinary bladder (UB) was measured. Also, the adrenal glands (AGs) (width of the cranial and caudal poles, length), kidneys (length, width, height), ovaries (length, width), testes (length, width), uterus (width) and seminal glands (width) and the thickness of the spleen and pancreas were measured. All the measurements were compared between age groups and sexes.Results: The liver, gallbladder, gastrointestinal tract, pancreas, spleen, kidneys, UB, AGs and great vessels were clearly visualised in all the guinea pigs. No significant statistical differences were found between the sexes, but there were statistically significant differences in the size of the kidneys, AGs, pancreas, spleen and reproductive organs between age groups. No significant differences in the wall thickness of the digestive system, gallbladder and UB were observed between groups.Limitations: The main limitation of this study is the lack of gross anatomical or histological correlation.Conclusions: The results of this study support the use of ultrasonography as a diagnostic tool in guinea pigs and provide reference values for the abdominal organs of this species.