Polydipsia in Pet Guinea Pigs

Introduction
Polydipsia in pet guinea pigs (pGp) is well known by guinea pig breeders (1). However an upper limit for daily water intake (DWi) in normodipsic pGp has not been reported. reference values for urine specific gravity in pGp have never been established (2).
aims of the study were to determine DWi for the normo- and polydipsic pGp and decide whether urine specific gravity can be used as a reliable marker for polydipsia.

Materials and methods
Twenty pGp were recruited according to pre-determined inclusion/exclusion criteria. ten pGp were normodipsic (C group) and 10 were polydipsic (pD group). urinary sam- pling and measurement of urine specific gravity by refractometry was performed at the hospital.

Results
The full range of DWi/kg body weight in the C-group was 16-55 mL and in the pD group 143-481 mL. the difference between groups was significant with p<0,0001. the median urine specific gravity was 1.019 (range: 1.005-1.038) in the C group and 1.017 (range: 1.007-1.031) in the pD group. the difference between groups was not significant (p=0,65).

Conclusions
The results suggest that the upper limit for DWi in normodipsic pGp is 55 mL/kg body weight and that a higher intake may indicate polydipsia. Low uSG is an unreliable indi- cator of polydipsia in pGp. these conclusions may be relevant in further studies of poly- dipsic disorders in pGp.