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SUMMARY

The effect of bethanechol, neostigmine, metoclopramide, and propranolol on myoelectric activity of the ileum, cecum, and proximal loop of the ascending colon was determined in 6 healthy Jersey cows implanted with 8 pairs of bipolar electrodes. Assigned at random, each cow received each of 5 treatments in 3-day intervals. The treatments included bethanechol (0.07 mg/kg of body weight, sc), neostigmine (0.02 mg/kg, sc), metoclopramide (0.15 mg/kg, im), dl-propranolol (0.2 mg/kg, im), and 0.9% sodium chloride (NaCl) solution (20 ml, sc). All drugs were administered during early phase I of the migrating myoelectric complex in the ileum. Myoelectric activity was recorded for 4 hours after treatment, and data were analyzed for each hour separately.

Bethanechol and neostigmine significantly (P < 0.05) increased the number of cecocolic spikes per minute per electrode, duration of cecocolic spike activity (%), and number of cecocolic propagated spike sequences per 10 minutes, relative to NaCl, during 1 or more hours of the recording period. The effect of bethanechol was more pronounced on duration of spike activity and number of propagated spike sequences, whereas neostigmine mainly increased the number of (uncoordinated) spikes. Metoclopramide and propranolol had no significant effect on cecocolic myoelectric activity, relative to NaCl.

It was concluded that bethanechol and, less likely, neostigmine at the dosage used in this study may be suitable for medical treatment of cecal dilatation in cattle in which hypomotility of the cecum and proximal loop of the ascending colon has to be reversed. The potential advantage of bethanechol vs neostigmine for medical treatment of cecal dilatation is worth further evaluation.

Free access
in American Journal of Veterinary Research

SUMMARY

The effect of xylazine, cisapride, and naloxone on myoelectric activity of the ileum, cecum, and proximal loop of the ascending colon (plac) was determined in 4 healthy Jersey cows implanted with 8 pairs of bipolar electrodes. A 4 × 4 Latin square design was used. The treatments included xylazine (0.04 mg/kg of body weight), cisapride (0.08 mg/kg), naloxone (0.05 mg/kg), and 0.9% sodium chloride solution (20 ml). All treatments were administered IV during early phase I of the migrating myoelectric complex in the ileum. Myoelectric activity was recorded for 4 hours after treatment, and data were analyzed for each hour separately.

Xylazine significantly (P < 0.05) increased the duration of phase I of the first migrating myoelectric complex in the ileum to 220.72 ± 26.89 minutes, compared with 30.91 ± 10.11 minutes after administration of 0.9% sodium chloride solution. The number of cecocolic spikes per minute per electrode and the duration of cecocolic spike activity (percentage of recording time) were significantly (P < 0.05) decreased for the first 3 hours, and the number of propagated spike sequences in the cecum and PLAC was significantly (P < 0.05) decreased for the first 2 hours after administration of xylazine. Significant difference was not found between control and either cisapride or naloxone treatment of healthy cows. However, during hour 1 after treatment with cisapride, number of spikes per minute, duration of spike activity, and number of propagated spike sequences were highest, compared with the other treatments.

It was concluded that naloxone at the dosage used in this study was not suitable for medical treatment of cecal dilatation in cattle, when hypomotility of the cecum and PLAC must be reversed. Xylazine should not be used for relief of signs of pain in cases of cecal dilatation, because it significantly reduced myo electric activity of the cecum and PLAC for at least 2 hours after treatment. Furthermore, results of this study indicated a trend (P > 0.05) toward increase of cecocolic myoelectric activity after administration of cisapride. It is the authors’ opinion that the potential benefit of cisapride for medical treatment of cecal dilatation in cattle needs further evaluation.

Free access
in American Journal of Veterinary Research

Summary

Six Jersey cows were implanted with 8 pairs of bipolar electrodes: 1 in the jejunum, 1 in the ileum, 3 in the cecum, and 3 in the proximal loop of the ascending colon (plac). Myoelectric activity was recorded at 2- to 3-day intervals, 3 times for 8 hours or 4 times for 6 hours, using a computer-based oscillograph and data-acquisition program.

Mean (± sd) duration of the migrating myoelectric complex (mmc) in the ileum was 84.52 ± 4.87 minutes. Phases I and II of the mmc lasted significantly (P < 0.05) longer than phase III. Two types (A and B) of cyclic activity were found in the cecum and plac. Cyclic activity type A was observed predominantly in the cecum, and type B was observed exclusively in the plac. Phase III of the mmc in the ileum was accompanied by hyperactivity type A at the level of the ileocecocolic junction in 60.90 ± 12.65% of the mmc. Twenty-seven types of orally and aborally propagated spike sequences, involving the cecum and plac, were found. They were most frequent when an mmc phase III was observed in the ileum, and least frequent when an mmc phase I was observed in the ileum (P < 0.05). All electrode sites of the cecum and plac served as pacemaker areas. Propagated and nonpropagated spikes were found at all electrode sites of the cecum and plac. Although propagated spikes lasted significantly (P < 0.05) longer than nonpropagated spikes, a clear distinction on the basis of duration could not be defined between the 2 spike types because broad overlapping of duration existed. Duration of cecocolic spiking activity per electrode (expressed as percentage of time) was significantly (P < 0.05) greater during mmc phase III in the ileum than during mmc phase I.

It can be concluded that myoelectric activity of the cecum is well coordinated with the ileum and the plac. Phases of reduced and increased myoelectric activity in the cecum and plac are simultaneous with phases I and III of the mmc in the ileum.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To estimate the prevalence of paratuberculosis in purebred beef cattle in Texas and identify risk factors for seropositivity.

Design—Epidemiologic survey.

Animals—4,579 purebred cattle from 115 beef ranches in Texas.

Procedure—Blood was collected, and serum was analyzed for antibodies with a commercial ELISA. Fecal samples were collected and frozen at −80°C until results of the ELISA were obtained, and feces from seropositive cattle were submitted for mycobacterial culture. Herd owners completed a survey form on management factors.

Results—Results of the ELISA were positive for 137 of the 4,579 (3.0%) cattle, and 50 of the 115 (43.8%) herds had at least 1 seropositive animal. Results of mycobacterial culture were positive for 10 of the 137 (7.3%) seropositive cattle, and 9 of the 50 (18%) seropositive herds had at least 1 animal for which results of mycobacterial culture were positive. Risk factors for seropositivity included water source, use of dairy-type nurse cows, previous clinical signs of paratuberculosis, species of cattle (Bos taurus vs Bos indicus), and location.

Conclusions and Clinical Relevance—Results suggested that seroprevalence of paratuberculosis among purebred beef cattle in Texas may be greater than seroprevalence among beef cattle in the United States as a whole; however, this difference could be attributable to breed or regional differences in infection rates or interference by cross-reacting organisms. Veterinarians should be aware of risk factors for paratuberculosis as well as the possibility that unexpected serologic results may be found in some herds. (J Am Vet Med Assoc 2005;226:773–778)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the use of sucrose permeability testing to detect ulcers in the gastric squamous mucosa of horses.

Animals—13 adult horses ranging from 5 to 19 years of age.

Procedure—Following induction of gastric ulcers by intermittent feed deprivation, horses underwent sucrose permeability testing (administration of sucrose by nasogastric intubation followed by collection of urine at 2 and 4 hours after intubation) and gastric endoscopy. Squamous ulcers were assigned a severity score (range, 0 to 3) by use of an established scoring system. Horses were subsequently administered omeprazole for 21 days, and sucrose testing and endoscopy were repeated. Pair-wise comparisons of urine sucrose concentration were made between horses with induced ulcers before and after omeprazole treatment. Urine sucrose concentrations also were compared on the basis of ulcer severity score.

Results—Urine sucrose concentrations and ulcer severity scores were significantly higher in horses with induced ulcers before omeprazole treatment than after treatment. Urine sucrose concentrations were significantly higher for horses with ulcer severity scores > 1. Use of a cut-point value of 0.7 mg/mL revealed that the apparent sensitivity and specificity of sucrose permeability testing to detect ulcers with severity scores > 1 was 83% and 90%, respectively. Results were similar after adjusting sucrose concentrations for urine osmolality.

Conclusions and Clinical Relevance—Urine sucrose concentration appears to be a reliable but imperfect indicator of gastric squamous ulcers in horses. Sucrose permeability testing may provide a simple, noninvasive test to detect and monitor gastric ulcers in horses. ( Am J Vet Res 2004;65:31–39)

Full access
in American Journal of Veterinary Research