Objective—To determine the correlation between
insulin concentrations and myoelectrical activity of
the abomasum in cows with a left displaced abomasum
Animals—14 dairy cows with an LDA at the onset of
Procedure—During surgical correction of an LDA, 3
pairs of electrodes were placed in the smooth muscle
of the gastrointestinal tract (abomasal body, pars
pylorica, and duodenum) of each cow.
Electromyographic recordings were obtained once
per day for 7 days. Samples were collected and tested
to determine concentrations of insulin, glucagon,
cortisol, glucose, β-hydroxybutyrate, and nonesterified
Results—All 14 cattle had high glucose and insulin
concentrations at the time of admission, independent
of ketosis. Concentrations of glucose and
insulin decreased slowly after surgical treatment and
were associated with a progressive increase in abomasoduodenal
myoelectric activity. The 14 cows
were allocated into 2 groups (suspected insulinresistant
cattle, n = 7; suspected non–insulin-resistant
cattle, 7) on the basis of persistent hyperinsulinemia
during the postoperative period. Seven days
after surgery, the abomasoduodenal myoelectric
patterns were still significantly lower for the insulinresistant
cows, compared with patterns for the
Conclusions and Clinical Relevance—Insulin
resistance appears to be common in cows with an
LDA. Analysis of results of this study reveals that
abomasal atony in cows with an LDA depends on
persistence of high serum concentrations of insulin.
Results of this study could provide an explanation
for a pathogenetic factor of LDAs and the frequent
relapses of cattle affected by this condition. (Am J
Vet Res 2004;65:1319–1324)
OBJECTIVE To compare the effectiveness of an ultrasound-guided paravertebral nerve blockade technique (UGPNB) with distal and proximal paravertebral nerve blockade techniques without ultrasound guidance (DPNB and PPNB, respectively) in calves.
ANIMALS 4 calf cadavers and 7 healthy calves.
PROCEDURES A suitable acoustic window was identified to facilitate access to the T13, L1, and L2 spinal nerves in cadavers and live calves. In cadavers, nerves were injected with dye under ultrasound guidance. In calves, the UGPNB, DPNB, and PPNB were performed in random order at 10-day intervals by injection of an anesthetic solution containing 2% lidocaine hydrochloride. Nociceptive withdrawal responses were assessed to determine the effects of the blockades.
RESULTS In cadavers, nerve staining success rates (ie, ≥ 2-cm-long dye path) achieved with ultrasound guidance were 88% (T13 [ventral branch]), 75% (T13 and L1 [dorsal branches] and L1 and L2 [ventral branches]), and 38% (L2 [dorsal branch]). The nerves were each identified as a hyperechoic band in a longitudinal plane. In calves, the UGPNB, DPNB, and PPNB reduced the withdrawal response to the noxious stimulus, mainly in the dorsal-cranial, dorsal-caudal, and ventral-cranial areas of the flank. Overall, the UGPNB resulted in a better nociceptive cumulative score, administering only one half of the local anaesthetic dose, compared with findings for the DPNB and PPNB. However, time to perform the UGPNB was longer.
CONCLUSIONS AND CLINICAL RELEVANCE The UGPNB evaluated may be an improved alternative to the DPNB and PPNB for provision of anesthesia for flank surgery in calves. However, effectiveness of the UGPNB should be evaluated in a clinical setting and in adult cattle.