Ultrasonographic assessment of the reticular motility in cows after administration of different doses of metoclopramide and neostigmine

The aim of the present study was to use of ultrasonography for assessment of reticular motility after administration of various doses of metclopramide and neostigmine in cows. A total of ten Holstein cows were used in six trials in each one single dose of each drug was used. Metoclopramide was used at 0.1, 0.2 and 0.3 mg/kg intramuscularly, whereas neostigmine was used at 0.02, 0.03, and 0.04 mg/kg subcutaneously. Reticular motility was assessed using 3.5 MHz transducer just before drugs administration and every 20 minutes after administration with total time of two hours. At twenty minutes postadministration, metoclopramide at a dose rate of 0.3 mg kg significantly (P < 0.01) produced shortening of the interval time between the two biphasic reticular contractions by 25% and significantly (P < 0.05) increased the amplitude of the first reticular contraction by 42%, but with mild neurological signs. Neostigmine produced non-significant increase in reticular contraction rate and strength. The results of the present study indicate that metoclopramide and neostigmine at selected doses are not clinically useful agents for increasing reticular contraction rate and strength. The findings of this study in healthy animals may not be extrapolatable to findings in cattle with reticuloruminal hypomotility.