In mammalian species studied previously, pepsinogen consisted of biochemically different groups of isozymogens. By use of gel filtration chromatography and electrophoresis, we isolated a predominant pepsinogen from the gastric mucosa of a horse. Peptide mapping with V8 protease revealed differences with its porcine homologue. However, porcine and equine pepsinogens, when activated to pepsin, had a similar pattern of activity when hemoglobin was used as substrate. Those results suggest that differences must exist in the primary structure of the pepsinogens of the 2 species.

Recumbency affects respiratory mechanics and oxygenation in anesthetized horses. Changes in pleural and abdominal pressures that can impair ventilation have not been described in all recumbencies. The objective of this study was to determine the effects of patient positioning on transdiaphragmatic pressure and selected hemodynamic variables. Horses were maintained under total intravenous general anesthesia with nasal oxygen supplementation. Transnasal balloon catheters in the stomach and thoracic esophagus were used to measure intrathoracic and gastric pressures in standing horses and in anesthetized horses positioned in right and left lateral recumbency, dorsal recumbency, reverse Trendelenburg position, and Trendelenburg position. Transdiaphragmatic pressure was calculated as the difference between gastric and intrathoracic pressures. Measurements of oxygen saturation (SpO(2)), heart rate, systolic, diastolic and mean arterial pressures, and respiratory rate were obtained every 5 minutes. When compared to dorsal recumbency, gastric expiratory pressure is decreased in the standing position. Thoracic expiratory pressure is decreased in standing and reverse Trendelenburg. Transdiaphragmatic expiratory pressure and SpO(2) are decreased in Trendelenburg. Heart rate is increased in reverse Trendelenburg. Systolic, diastolic, and mean arterial pressures are decreased in reverse Trendelenburg and increased in left lateral and right lateral recumbency. We found that there is wide variation in respiratory pressures between horses and positions and they are not predictive of associated changes in hemodynamic variables.

OBJECTIVE To compare load-to-failure results for laparoscopic absorbable fixation straps (AFSs) deployed at various angles and for AFSs versus absorbable knotless (barbed) suture when used in simulated total laparoscopic gastropexy (TLG) in specimens from cadaveric dogs. SAMPLE 30 stomach and abdominal body wall specimens. PROCEDURES Specimens were assigned to 1 of 3 groups for use in simulated TLG constructs for comparisons of load-to-failure results for single AFSs deployed at 30°, 60°, or 90° (AFS-angle group; n = 10) or for a gastropexy span of 4 to 5 cm achieved with 3-0 absorbable knotless (barbed) monofilament suture applied in a simple continuous pattern (TLG-1; 10) versus 8 AFSs applied with a deployment angle > 30° (TLG-2; 10). A 1-way ANOVA was used to compare results among AFS deployment angles (30°, 60°, or 90°) and between TLG-1 and TLG-2. RESULTS Mean ± SD load to failure for the AFS-angle group was significantly higher for the AFS deployment angles of 60° (8.00 ± 3.90 N) and 90° (12.71 ± 8.00 N), compared with 30° (5.17 ± 1.90 N). However, no substantial difference was detected in the mean ± SD load to failure for TLG-1 (39.18 ± 7.1 N) versus TLG-2 (31.43 ± 10.86 N). CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study supported the potential use of AFSs in gastropexy in dogs; however, prospective clinical research with adequate long-term follow-up is warranted before recommendations can be made.

OBJECTIVE To biomechanically assess outcomes for 2 percutaneous gastropexy techniques and determine the amount of time necessary to perform the techniques for securing percutaneous endoscopic gastrostomy (PEG) tubes in canine cadavers. ANIMALS 18 canine cadavers. PROCEDURES 6 cadavers were assigned to each of 3 groups (PEG tube only, PEG tube with T-fastener gastropexy, and PEG tube with U-stitch gastropexy). Time to completion of placement of a PEG tube and gastropexy was recorded. After tubes were placed, the stomach and body wall on the left side of the abdomen were removed and biomechanically tested. Maximum tension at the time of initial failure of the PEG tube or gastropexy was recorded. RESULTS Significantly more force was required to induce failure for the T-fastener and U-stitch techniques than for the PEG tube only technique. In addition, both the T-fastener and U-stitch techniques required significantly more time for placement than did the PEG tube only technique. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that performing a T-fastener or U-stitch gastropexy may decrease the risk of early dislodgement of a PEG tube in dogs. However, studies conducted with these techniques in live dogs would be necessary to confirm this hypothesis. The additional amount of time needed to perform the T-fastener or U-stitch gastropexy would likely be clinically unimportant.

OBJECTIVE To assess the feasibility of esophageal insufflation CT (EICT) for evaluation of the esophagus in dogs. ANIMALS 7 clinically normal adult Beagles. PROCEDURES Each dog was anesthetized twice with 1 week between anesthesia sessions. Dogs were positioned in sternal recumbency during all CT scans. During the first anesthesia session, a CT scan was performed before the esophagus was insufflated (insufflation pressure, 0 mm Hg) and unenhanced and contrast-enhanced EICT scans were performed after CO(2) was insufflated into the esophageal lumen to achieve a pressure of 5 mm Hg. For the contrast-enhanced scan, each dog received iohexol (600 mg/kg, IV), and the scan was performed 30 seconds later. During the second anesthesia session, unenhanced and contrast-enhanced EICT scans were performed in the same manner except the insufflation pressure achieved was 10 mm Hg. The esophageal luminal cross-sectional area and wall thickness were measured at each of 5 segments, and mean values were compared among the 3 insufflation pressures and between unenhanced and contrast-enhanced images. RESULTS Mean esophageal luminal cross-sectional area increased and esophageal wall thickness decreased as insufflation pressure increased. Measurements did not differ significantly between unenhanced and contrast-enhanced images. The stomach became distended with CO(2) at an insufflation pressure of 10 mm Hg but not at 5 mm Hg. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested EICT was feasible for esophageal evaluation in dogs. Further research is necessary to determine the optimal insufflation pressure for the procedure and its diagnostic efficacy in diseased patients.

OBJECTIVE To evaluate effects of laparoscopic-assisted incisional gastropexy (LAIG) on gastric motility in dogs by use of a wireless motility device (WMD). ANIMALS 10 healthy client-owned large or giant-breed dogs. PROCEDURES 10 dogs owned by clients interested in prophylactic LAIG were enrolled. To determine effects of LAIG on gastrointestinal motility in dogs during the nonfed state, each dog was evaluated by use of a noninvasive WMD before and > 4 weeks after LAIG. All dogs underwent LAIG, with or without concurrent elective gonadectomy. Data obtained before and after LAIG were analyzed by use of proprietary software to determine the gastric emptying time, small bowel transit time, large bowel transit time, whole bowel transit time, and motility index. RESULTS No changes in variables were detected between measurements obtained before and after prophylactic LAIG. CONCLUSIONS AND CLINICAL RELEVANCE In this study, prophylactic LAIG did not have an effect on gastrointestinal motility. The WMD was tolerated well by all dogs and appeared to be a safe and effective method for evaluating gastrointestinal motility in this population of dogs.