Untersuchungen zur Ursache des generalisierten Haarausfalls bei jungen Kälbern

In the past few years alopecia has been observed in calves that
were admitted to our clinic because of diarrhea and/or ruminal
drinking. The aim of this prospective study was to investigate
whether there is a causal relationship between ruminal drinking and
generalized alopecia. Data from a total of 270 animals aged 31 days
or younger that were admitted to the clinic for various reasons –
and discharged after successful treatment were analysed. Animals
whose general condition did not allow the collection of samples
were excluded from the study. On the day of admission blood
samples, rumen liquid, and hair-pluck samples from three defined
regions of the body (forehead, withers, tail base) were taken. On
the following day, preferably twenty-four hours later, these
procedures were repeated. The fluid taken from the rumen was
examined for gross evidence of casein, and the pH-value was
measured. If the pH was above six on the first day, but below than
six on the second day, rumen liquid was taken again on the third
day. A differentiation between simple ruminal drinking (pH below
six on the first day of the study), and complicated ruminal
drinking (pH below six on two consecutive days) was obtained by
following the described procedure. Up to the day of discharge the
hair-pluck samples and visual examination were carried out daily. A
total of 76 of the examined animals developed alopecia. Animals
with alopecia were significantaly more often diagnosed with
complicated ruminal drinking than animals without hairloss. With
regard to simple ruminal drinking, presence of casein , and
force-feeding (according the history) the groups were not
significantly different. Significant differences were observed
between the groups with reference to base excess,
hydrogen-carbonate, D-lactate, urea, creatinine and the enzymes
glutathione peroxidase, aspartate amino-transferase, as well as
creatine kinase. Analysis of the blood values of L-lactate and
glucose did not show significant differences. Calves with hair loss
remained in the Clinic significantly longer than animals without
alopecia. On the basis of the results, the following causal
relationships are assumed: Alopecia and complicated ruminal
drinking represent after-effects of serious diarrheal illness in
the newborn calf. These secondarly problems seem to be independent
of each other. Alternatively, it could be hypothesized that
complicated ruminal drinking leading to a protracted ruminal
acidosis could induce alopecia. Furthermore, it can be assumed that
serious neonatal diarrhea alone could cause generalized hair loss
in calves. This assumption is supported by the results of this
study which show that the majority of the animals included in this
investigation suffered from severe diarrhea but were not diagnosed
with ruminal acidosis during the observation period. A variety of
disturbances caused by severe diarrheal illness possibly influence
the metabolism of the hair. D-lactatemia, dehydration, or blood
acidosis could be of relevance in this context. The mechanisms that
cause alopecia during serious illness should be the subject of
further studies.