Retrospektive Untersuchung zur Aussagekraft verschiedener Parameter im Hinblick auf den Grad der Dehydratation bei Kälbern mit Durchfall

In the present study the data of 156 calves of different breeds,
aged two to twelve weeks, with neonatal diarrhoea were evaluated
retrospectively. The calves were in-patients in the II.
Medizinischen Tierklinik of the LMU München in 1997 and 1999, where
the necessary data were collected. The aim of this study was to
find out, how certain easily obtainable findings change with the
severity of the disease. This was conducted with the results of the
macroscopic (colour, grade of cloudiness and pollution) and
physical (specific gravity)urine examination, the serum- and
urine-concentrations of creatinine (SCr and UCr), urea (SHst and
UHst) and sodium and the parameters Ucr / Scr, UHst / SHst and
EFNa. Factors that may lead to deviation of the results during
sampling were additionally considered. It was revealed that
especially the specific gravity and the colour of the urine sample
are suitable for the confirmation of the clinically diagnosed
degree of dehydration. The specific gravity increased from x =
1022.2 in non-dehydrated patients to x = 1029.3 in patients with
severe dehydration. The colour of the urine sample, assessed
macroscopically and subjectively, was stated to be darker with an
increasing grade of dehydration. The quotient Ucr / Scr does not
support the estimation of the grade of dehydration. Accompanied by
an increasing dehydration serum concentrations of creatinine and
urea and urine concentration of creatinine increased. The urine
concentration of creatinine correlated to the specific gravity (r =
0.73) and significantly rose in samples of darker colour. The
proportion of animals with an eliminated fraction of sodium (EFNa )
greater than 1% among patients with urine of light colour was
remarkable. This corresponds to the findings that also an Ucr / Scr
-quotient below 37 was frequently found in calves with urine of
light colour. Both indicates a restricted renal function caused by
impairment of the tubular reabsorption of sodium or glomerular
filtration, respectively. To evaluate influences on the results of
urine examination, that play a part during sampling, factors as
spontaneous or provoked collection of urine, sex and grade of the
samples´ cloudiness and pollution were taken into account. None of
these lead to a distinct change of findings. The results of this
study show the possibilities of an extended diagnosis of
dehydration grade in calves with neonatal diarrhoea. An eventual
damage of renal parenchyma may be suspected considering the Ucr /
Scr –quotient and the EFNa . This might be important for the
patient’s prognosis. The deviation of the findings of urine
examination by factors of sampling is supposed to be of lesser
importance for diagnosis.