Pitfalls in the measurement of canine urine concentration
Allchin, J.P.; Evans, G.O.; Parsons, C.E.
Veterinary Record 120(11): 256-257
1987
ISSN/ISBN: 0042-4900 PMID: 3576935 Document Number: 299177
The degree of concentration of 30 canine urine samples from healthy Beagles was measured by depression of freezing point (using a Roebling micro-osmometer) and by refractometry (using an Atago uricon meter). Results were compared with those obtained using a solid-phase reagent strip containing a poly-electrolyte indicator system. All of the test strip values were lower than those of the refractometer and only two agreed within 0.005. For a single specific gravity figure the urine osmolality varied considerably, for example for test strip 1.020 the osmolality figures were from 1111 to 2000 mosmol/kg. In addition, since the calibration scales of some refractometers have been changed to decrease figures compared with those of older instruments, consideration of the model is necessary.