Calves experimentally infested with Sarcoptes bovis were treated 14 weeks post infectionem with an
avermectin pour-on preparation (
Ivomec). On day 0 before and 14, 28 and 56 days
after treatment mite count,
scabies lesion score, histological sections of the skin, blood- (number of erythrocytes, PCV, Haemoglobin, MCV, MCH, MCHC, number of leukocytes, differential blood picture) and serum parameter (GOT/AST, GGT, GLDH,
glucose,
calcium, magnesium, phosphate,
sodium,
potassium and
chloride) and Sarcoptes specific
immunoglobulin G and
immunoglobulin M were determined. 14 days
after treatment no mites could be found in skin scrapings and the
mange lesions were in recovery stage. 28 days
after treatment the skin mostly was macroscopically unchanged. On all examination days in skin biopsies hyperkeratosis, mostly accompanied by epidermal
hyperplasia and perivascular infiltration with eosinophil granulocytes and mononuclear cells was observed. The dominance of eosinophil granulocytes in the tissue decreased
after treatment, while mononuclear cells increased and dominated in most cases on day 28 over eosinophil granulocytes. The differential blood count in most cases showed elevated lymphocytes on all examination days, increase of neutrophil granulocytes and decrease of eosinophil granulocytes between day 0 and 14. Monocytes on day 28 showed a marked decrease, thereafter on day 56 a marked elevation. Slightly increased serum
enzyme activities were seen with GLDH and GOT on day 0 before treatment and with GLDH on day 56
after treatment. The specific antibody titer against Sarcoptes
antigen showed decreasing
immunoglobulin G titre and increasing
immunoglobulin M titre during the investigation.