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Objective: The objective of this study was to analyze the use of rebound tonometry, as a noninvasive diagnostic tool, in arachnids., Methods: 5 juvenile (yearling) female and 1 juvenile male curlyhair tarantulas (Tliltocatl albopilosus, previously Brachypelma albopilosum) were used to track estimated ventral opisthosoma pressures over a 9-month period of time. Younger, growing animals were selected as they are more likely than adults to go through multiple molts throughout the 9 months of the study length. An iCare TONOVET TV01 rebound tonometer was used to measure the estimated ventral opisthosoma pressures of the spiders. Measurements were obtained from the ventral opisthosoma, 1 of the thinnest areas of exocuticle throughout the body. Readings were obtained once per week from the ventral opisthosoma for the first 2 months, then once every 2 weeks for 1 month, then back to once per week for the remainder of the study. Additional measurements were obtained following each ecdysis, after a 2% body weight sampling of hemolymph, and at the end of the study to evaluate readings in response to induction of general anesthesia with 5% isoflurane gas and oxygen flow at 2 L/min for 10 minutes., Results: The average of all estimated ventral opisthosoma pressure when spiders were not in molt was 26.19 mm Hg (SD, 3.54), with a statistically significant decrease postmolt to an average of 15.31 mm Hg (SD, 3.81), followed by a gradual increase back to premolt pressures over a 3-week period with an average of 22 days (SD, 1.93). Estimated ventral opisthosoma pressures decreased post hemolymph removal. There is not sufficient evidence that estimated ventral opisthosoma pressures changed over time following the anesthesia., Clinical Relevance: This study demonstrates that tonometry can be used to generally assess the estimated ventral opisthosoma pressure, which could correlate with where a spider is in an ecdysis cycle.

Objective: To evaluate the accuracy, precision, and observer agreement of three pressure measurement devices., Study Design: In vitro model study., Sample Population: Water manometer with built-in gauge (WMg), arterial pressure transducer (APT), and Compass CT (CCT)., Methods: The model was set to five predetermined pressures (4, 8, 13, 17, and 24 cm H 2 O) using a water manometer with a ruler (WMr) as the gold standard. Each device was tested at each pressure in a randomized order by three investigators. Bland-Altman plots were used to assess agreement between devices. Intraclass correlation coefficients (ICC) were calculated for interobserver and intraobserver agreements., Results: The mean differences (cm H 2 O) ± SEM in comparison with the set pressure were -0.020 ± 0.010 (WMg), -0.390 ± 0.077 (APT), and -1.267 ± 0.213 (CCT). Pressures measured by WMg did not differ from those measured by WMr. Pressures measured by all devices did not differ from each other (p > .062 for all comparisons). Interobserver agreement was excellent (1.000), and intraobserver agreement was excellent (0.985, 0.990, 0.998 for each observer)., Conclusion: Compared to the WMr, the WMg was the most accurate and precise, followed by the APT; the CCT was the least accurate and precise. Interobserver and intraobserver agreements for all three devices were excellent., Clinical Significance: The largest mean difference of all devices was within 1.3 cm H 2 O of the set pressure, indicating possible clinical utility of any of the devices. However, WMr or WMg should be considered first due to their high precision and accuracy., (© 2023 The Authors. Veterinary Surgery published by Wiley Periodicals LLC on behalf of American College of Veterinary Surgeons.)

Objective: To compare intraocular pressure (IOP) measurements in dogs taken with the Reichert® Tono-Vera® Vet rebound tonometer with and without the automatic positioning system., Animals Studied: Measurements were taken on 49 eyes from 26 Beagle-derived dogs with variable genetics-four non-glaucomatous and 22 ADAMTS10-mutant dogs affected with different stages of open-angle glaucoma. Seventeen of the 26 dogs were measured 2-4 times on different days with variable intervals since IOP-lowering medications were administered., Procedures: In each dog, tonometry was performed with the Tono-Vera® Vet using three different methods in a randomized order: (Method 1) Average of three readings with an automatic positioning system; (Method 2) one reading with an automatic positioning system; and (Method 3) average of three readings obtained without the automatic positioning system. Statistical analyses included one-way ANOVA, Tukey pairwise comparisons, and Bland-Altman plots (MiniTab®)., Results: With each of the three tonometry methods, 116 measurements were taken, resulting in 348 total IOP measurements with a range of 12.8-49.9 mmHg. The means and standard deviations for each method were 25.4 ± 6.9 mmHg (Method 1), 26.0 ± 7.2 mmHg (Method 2), and 26.9 ± 7.7 mmHg (Method 3), with no significant differences (p = .27). Mean IOP variances were also not significantly different between tonometry methods (p = .24 to .78)., Conclusions: Because mean IOPs and their standard deviations were not statistically different between the three tonometry methods, we conclude that Tono-Vera® Vet measurements conducted without the aid of the positioning system still provide reliable results., (© 2023 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.)

Objective: To compare the measurement of intraocular pressure in horses with clinical ocular disease using three tonometry devices., Animals Studied: A total of fifty horses were presented to the New Bolton Center Ophthalmology Service., Procedure: Intraocular pressure was taken on 50 client-owned horses (100 eyes) using the TonoVet, TonoVet Plus and Tono-Pen Avia tonometers. Clinical equine patients included were presented to New Bolton Center for ophthalmic examination. Auriculopalpebral blocks were performed but horses were unsedated., Results: All three tonometers were found to have strong agreement among them. The strongest agreement was between the TonoVet and the TonoVet Plus with the TonoVet on average 1.330 mmHg less than the TonoVet Plus (standard deviation 4.388 mmHg). This was followed by the TonoVet and the Tono-Pen Avia Vet with the TonoVet on average 2.531 mmHg greater than the Tono-Pen Avia Vet (standard deviation 4.124 mmHg). The weakest agreement was between the TonoVet Plus and the Tono-Pen Avia with the TonoVet Plus on average 3.854 mmHg greater than the Tono-Pen Avia (standard deviation 4.724 mmHg)., Conclusions: All three tonometers showed strong agreement, however, the TonoVet and the TonoVet Plus carried the strongest agreement with the TonoVet Plus having slightly higher measurements overall compared with the TonoVet. Due to small variations between devices, it is recommended that the same device be used for serial measurements of intraocular pressure. However, all three devices are appropriate to use in horses presented for ophthalmic evaluation., (© 2023 American College of Veterinary Ophthalmologists.)

Objective: The objectives of the study were to compare intraocular pressure (IOP) readings across a wide range and obtained via three rebound tonometers in ADAMTS10-mutant Beagle-derived dogs with different stages of open-angle glaucoma (OAG) and normal control dogs and to investigate the effect of central corneal thickness (CCT)., Animals Studied: Measurements were performed on 99 eyes from 50 Beagle-derived dogs with variable genetics-16 non-glaucomatous and 34 with ADAMTS10-OAG. Seventeen OAG eyes were measured twice-with and without the use of IOP-lowering medications., Procedures: IOP was measured in each eye using three tonometers with their "dog" setting-ICare® Tonovet (TV), ICare® Tonovet Plus® (TVP), and the novel Reichert® Tono-Vera® Vet (TVA)-in randomized order. CCT was measured with the Accutome® PachPen. Statistical analyses included one-way ANOVA, Tukey pairwise comparisons, and regression analyses of tonometer readings and pairwise IOP-CCT Pearson correlations (MiniTab®)., Results: A total of 116 IOP measurements were taken with each of the three tonometers. When comparing readings over a range of ~7-77 mmHg, mean IOPs from the TV were significantly lower compared with TVP (-4.6 mmHg, p < .001) and TVA (-3.7 mmHg, p = .001). We found no significant differences between TVA and TVP measurements (p = .695). There was a moderate positive correlation between CCT and IOP for TVA (r = 0.53, p < .001), TVP (r = 0.48, p < .001), and TV (r = 0.47, p < .001)., Conclusions: Our data demonstrate strong agreement between TVP and TVA, suggesting that the TVA may similarly reflect true IOP values in canines. CCT influenced IOP measurements of all three tonometers., (© 2022 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.)

Objective: To determine intraocular pressure (IOP) estimates using rebound tonometry in juvenile northern bobwhite quails., Animals Studied: Eighteen, 28-day-old, wild caught, captive raised, northern bobwhite quails., Procedures: Birds were manually restrained in sternal recumbency with two fingers placed below the head, applying minimal pressure. Following detailed ophthalmic examination by a board-certified veterinary ophthalmologist, IOP was obtained via rebound tonometry using the Tonovet "P" setting for undefined species in animals without obvious ocular pathology. IOPs were estimated three times on each eye. The mean result of the three estimates was recorded for further analysis. Only readings with low or no reported error were recorded., Results: No difference was detected between the eyes; therefore, a reference interval was calculated using both eyes. The overall IOP (n = 36 eyes) was 5.6 ± 1.2 mmHg (mean ± SD), the median was 6 mmHg, and the range was 2-7 mmHg. The 95% reference interval was 2.2-7.6 mmHg. All quails were ultimately released with no clinically appreciable abnormalities., Conclusions: This study provides information on normal IOP values for juvenile northern bobwhite quails, which can be used to evaluate the ocular health of this species. Future studies with a larger number of animals are needed, as well as validation of the rebound tonometry method using direct manometry., (© 2022 American College of Veterinary Ophthalmologists.)

Objective: To compare single and triplicate applanation tonometry values across previous intraocular pressure (IOP) studies in dogs., Animals: 116 ophthalmologically normal dogs., Procedures: Triplicate IOP readings (n = 1432) from studies evaluating effect of anesthetic protocols were analyzed to estimate a range of probable differences between averaged triplicate and first, averaged and lowest, and first and lowest IOPs. The decrease in variability with triplicate measurements and the magnitude of effects on statistical power were quantified., Results: The 2.5th to 97.5th interpercentile range for differences of averaged triplicate values minus first IOP readings was -3 to 2.7 mm Hg; for averaged minus lowest: 0 to 3.7 mm Hg; for first minus lowest: 0 to 5 mm Hg. The 95% prediction interval for differences in study group means (n = 160 groups, n = 5 to 11 eyes per group) based on averaged minus first measurements was -1.0 to 0.9 mm Hg with associated SDs reduced by 4% on average. Analysis of previous studies using averaged instead of first IOP values resulted in minimal decreases in SEs of 3-9% (0.03 to 0.09 mm Hg). Of 11 comparisons found significant with averaged data, 2 (18%) were found nonsignificant with first measurements. Of 96 comparisons found nonsignificant with averaged data, 3 (3%) were found significant with first measurements., Clinical Relevance: With applanation tonometry in ophthalmologically normal dogs, no clinically meaningful difference was found between the first, lowest, or averaged triplicate IOP measurements, but the first reading has a larger variance and hence will result in lower statistical power.

Ocular disease in pinnipeds under human care is well described, and intraocular pressure (IOP) can be impacted by a variety of ophthalmic conditions. Species-specific reference parameters from clinically normal animals are instrumental for understanding how ophthalmic diseases may impact ocular pressures. IOP measurements were obtained using rebound tonometry from free-ranging Peruvian fur seals ( Arctocephalus australis unnamed subspecies) at Punta San Juan, Peru, over a 6-yr period (2010-2016). Retrospective data obtained from 108 (81 adults and 27 neonates comprising 69 females and 39 males) anesthetized fur seals with normal anterior segment ophthalmic examinations was included in the analysis. Differences in IOP from each eye were compared to categorical variables (age, year, sex, restraint) using an independent-samples t test. All univariate results with a significance of P < 0.05 were included in multivariate analysis. Of the 13 general linear models evaluated, the top two for both the right and the left eye included age class when all variables were evaluated simultaneously. Neonates had significantly lower IOP values than adults in both the right eye (17.5 mm Hg; 95% confidence interval [CI]: 14.0-21.1 mm Hg compared to 33.5 mm Hg; 95% CI: 31.0-36.1 mm Hg, respectively) and the left eye (18.4 mm Hg; 95% CI: 14.4-22.5 mm Hg compared to 32.3 mm Hg; 95% CI: 29.3-35.3 mm Hg, respectively). Anesthesia method was not statistically significant ( P > 0.05). This is the first report of normal IOP measurements for any fur seal species. Described data can be used to improve diagnosis and management of ocular alterations in pinnipeds.

Objective: To compare intraocular pressures (IOPs) estimated by rebound and applanation tonometry for dogs with lens instability., Animals: 66 dogs., Procedures: Medical records of dogs examined between September 2012 and July 2018 were reviewed for diagnoses of anterior (ALL) or posterior (PLL) lens luxation or lens subluxation., Results: Estimates of IOP obtained with rebound and applanation tonometry significantly differed from each other for all types of lens instability considered collectively (mean ± SE difference between tonometric readings, 8.1 ± 1.3 mm Hg) and specific types of lens instability considered individually (mean ± SE difference between tonometric readings: ALL, 12.8 ± 2.5 mm Hg; PLL, 5.9 ± 1.7 mm Hg; subluxation, 2.8 ± 0.8 mm Hg). Median (range) differences between rebound and applanation tonometer readings for dogs with ALL was 5 mm Hg (-9 to 76 mm Hg), with PLL was 3 mm Hg (-1 to 19 mm Hg), and with lens subluxation was 3 mm Hg (-9 to 18 mm Hg). In eyes with ALL, rebound tonometer readings exceeded applanation tonometer readings on 44 of 60 (73%) occasions., Conclusions and Clinical Relevance: Rebound tonometry yielded higher estimates of IOP than did applanation tonometry in eyes with ALL and with all types of lens luxation considered collectively. Estimates of IOP in eyes with lens instability should ideally be obtained with both rebound and applanation tonometers. Veterinarians with only one type of tonometer should interpret results for dogs with lens instability concurrent with physical examination findings.

Primary Objective: To evaluate the effect of latex tip cover manufacturer on accuracy and repeatability of Tono-Pen Vet™ in canine eyes., Animal Studied: Twelve enucleated globes from six dogs., Procedures: The anterior chamber was cannulated and connected to a calibrated manometer. Intraocular pressure (IOP) measurements were obtained using the Tono-Pen Vet and TONOVET Plus at manometric IOP ranging from 5 to 80 mmHg. At each IOP, the Tono-Pen Vet was used with a new Ocu-Film™ latex tip cover (the only manufacturer-approved brand of cover) followed by a new Softips™ latex tip cover. For comparison, the TONOVET Plus was also used at each IOP with a new disposable rebound probe. Measured IOP values were analyzed by linear regression and intraclass correlation coefficient (ICC)., Results: Tono-Pen Vet accuracy was unaffected by tip cover manufacturer or by frequent change in cover. Using ICC analysis, repeatability of measurements using either tonometer was good to excellent at physiologic IOP levels but variably decreased with both devices at supraphysiologic IOP., Conclusions: Neither tip cover manufacturer nor frequent changes in tip cover adversely affect Tono-Pen Vet accuracy. Measurement repeatability with Tono-Pen Vet and TONOVET Plus is widely variable at supraphysiologic IOP. Therefore, minor changes in IOP >25 mmHg should not be used to make clinical decisions without considering this variability., (© 2021 American College of Veterinary Ophthalmologists.)

Objective: To determine if there is a difference in intra-abdominal pressure (IAP) among 3 anatomic body positions (right lateral, left lateral, and sternal recumbence) in apparently healthy dogs., Design: Prospective, observational study., Setting: University Veterinary Medical Teaching Hospital., Animals: Fourteen apparently healthy male dogs., Measurements and Main Results: After mild sedation with dexmedetomidine, a water manometer attached to a Foley urinary catheter was used to measure IAP in 3 different body positions in each dog. There was no significant difference in IAP between right lateral (3.87± 3.16 cm H 2 O), left lateral (4.45 ± 3.22 cm H 2 O), and sternal recumbence (4.04 ± 3.57 cm H 2 O)., Conclusions: Based on data from these 14 apparently healthy dogs, these 3 body positions can be used interchangeably for monitoring an individual dog. However, more research in dogs is needed to see if this conclusion holds true when IAP is abnormal., (© Veterinary Emergency and Critical Care Society 2020.)

Objective: To evaluate the use of gastric (PgCO 2 ) and bladder (PbCO 2 ) tonometry for assessing tissue hypoperfusion in dogs during sevoflurane-induced hypotension, and to compare these measurements with delivery of oxygen, arterial oxygen content, and plasma lactate concentration., Design: Prospective experimental trial., Setting: University veterinary teaching hospital., Animals: Fourteen adult Beagle dogs., Interventions: Anesthetic induction was performed by mask with sevoflurane and oxygen. Heart rate, direct arterial pressures, respiratory rate, and end-tidal carbon dioxide were recorded; arterial blood samples were taken to measure blood gases, and venous samples were sampled to measure plasma lactate. A tonometric catheter was introduced into the stomach to measure PgCO 2 . Samples of saline from the balloon of a Foley catheter placed in the bladder were collected every 10 minutes and used to measure PbCO 2 by gas analysis. Tonometry measurements, plasma lactate, and oxygen delivery and consumption were compared at 3 time points: at baseline, during hypotension, and during treatment periods. A hypotensive period (mean arterial pressure (MAP) < 60 mm Hg) of 15 minutes was induced by an overdose of sevoflurane, whereas during the treatment period, a constant-rate infusion of dopamine (10 μg/kg/min) was administered intravenously for 40 minutes., Measurements and Main Results: Values for PgCO 2 and PbCO 2 increased significantly during the hypotensive period, and correlations were found between these values and the delivery of oxygen. Gastric tonometry values had stronger correlations compared with bladder tonometry values., Conclusions: Gastric and bladder tonometry can be used to detect hypoperfusion. Further studies are warranted to determine the potential use of gastric and bladder tonometry in assessing dogs in clinical situations., (© Veterinary Emergency and Critical Care Society 2017.)

Objective: To evaluate the feasibility of ultrasound biomicroscopy (UBM) and tonometry in pigeons and to provide biometric reference ranges for normal pigeon eyes., Animals Studied: Ten pigeons (Columba livia var. domestica) with ophthalmologically normal eyes., Procedures: Ophthalmic examinations, including slit-lamp biomicroscopy and tonometry, were performed to confirm that the eyes were normal. UBM was then performed on the left eye. On each obtained image, the ciliary cleft (CC) length, CC width, and CC area, and iridocorneal angle (ICA) were measured., Results: Richly vascularized iris was observed in all pigeon eyes. Mean intraocular pressure was 11.7 ± 1.6 mmHg, without any statistical difference between the left and right eyes. The UBM scanning procedure was well tolerated in all pigeons. Mean values of CC length, CC width, CC area, and ICA were 1.55 ± 0.17 mm, 0.36 ± 0.05 mm, 0.39 ± 0.04 mm 2 , and 15.17 ± 1.06°, respectively., Conclusions: Ultrasound biomicroscopy could be a useful diagnostic tool to evaluate anterior ocular segment of pigeons., (© 2017 American College of Veterinary Ophthalmologists.)

Tonometry, an indirect measurement of intraocular pressure (IOP), is important for the diagnosis and management of glaucoma and uveitis. The aim of this study was to compare the performance of three hand-held tonometers in normal canine eyes. Eyes from cadavers of dogs without observable ocular disease were used to compare tonometric measurements with direct manometry over a range of 7.4-65mmHg. In vivo measurements using the three tonometers in both eyes of 12 healthy dogs were compared. All tonometers significantly underestimated manometric values both ex vivo and in vivo. One tonometer showed a small fixed bias over the range of IOP, whilst the other two tonometers had a negative proportional bias. The results of this study show that differences exist between handheld tonometers across the clinically relevant range of IOP, and that all underestimate manometric measurements., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

OBJECTIVE To validate the use of high-resolution manometry (HRM) in awake, healthy dogs and compare the effects of bolus type (liquid vs solid) and drug treatment (saline [0.9% NaCl] solution [SS] vs cisapride) on esophageal pressure profiles. ANIMALS 8 healthy dogs. PROCEDURES In a crossover study, each dog received SS (10 mL) IV, and HRM was performed during oral administration of 10 boluses (5 mL each) of water or 10 boluses (5 g each) of canned food. Cisapride (1 mg/kg in 60 mL of SS) was subsequently administered IV to 7 dogs; HRM and bolus administration procedures were repeated. Two to 4 weeks later, HRM was repeated following administration of SS and water and food boluses in 4 dogs. Pressure profile data were obtained for all swallows, and 11 outcome variables were statistically analyzed. RESULTS After SS administration, predicted means for the esophageal contractile integral were 850.4 cm/mm Hg/s for food boluses and 660.3 cm/mm Hg/s for water boluses. Predicted means for esophageal contraction front velocity were 6.2 cm/s for water boluses and 5.6 cm/s for food boluses after SS administration. Predicted means for residual LES pressure were significantly higher following cisapride administration. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that HRM was feasible and repeatable in awake healthy dogs of various breeds and sizes. Stronger esophageal contractions and faster esophageal contraction velocity occurred during solid bolus and liquid bolus swallows, respectively. Lower esophageal sphincter pressure increased significantly following cisapride administration. Esophageal contractions and bolus transit latency should be further evaluated by HRM in clinically dysphagic dogs.

Twenty-two captive adult European pond turtles (12 males and 10 females) were unrestrained without sedation while intraocular pressure (IOP) was measured by means of a Tonovet®. Mean±SD IOP values between 8 and 10 am for all turtles were 5.42±0.96 mm Hg (range, 3-9 mm Hg). IOP between the right and left eye and between males and females was not significantly different. There was no correlation between IOP and body weight or body length of animals.

Objectives: The objectives of this study were to determine (1) most appropriate volume of saline to be infused into the bladder prior to intra-abdominal pressure (IAP) measurement, (2) to determine if a difference exists between IAP measurements before and after abdominal surgery, and (3) to assess the variability in IAP measurements associated with different saline volumes., Design: Prospective study., Setting: University teaching hospital., Animals: Fifteen female research dogs, 7 undergoing ovariohysterectomy (OHE), and 8 undergoing laparoscopy., Interventions: All dogs had urinary catheters placed and 4 consecutive IAP measurements measured using a different volume of instilled saline (0.25, 0.5, 1, and 2 mL/kg) at baseline. Measurements were repeated intraoperatively in laparoscopy dogs and postoperatively in OHE dogs., Measurements and Main Results: For both groups of dogs, the volume infused into the bladder significantly affected IAP measurement. An instilled volume of 1 mL/kg of saline produced the best correlation (R(2) = 0.44, P = 0.04) between IAP measurement and laparoscopic insufflator pressure. The mean (±SD) preoperative IAP (cmH2 O) using 1 mL/kg instilled saline was 7.9 ± 1.4 and 9.6 ±1.9 for laparoscopy and OHE dogs, respectively. There was no difference in IAP before and after surgery in the dogs undergoing an OHE (P = 0.58). The volume of saline instilled into the bladder significantly affected the IAP (P = 0.0028)., Conclusions: One milliliter per kilogram instilled saline is recommended for standardized IAP pressure measurement in dogs. IAP in clinically normal dogs was not affected by abdominal surgery., (© Veterinary Emergency and Critical Care Society 2014.)

Objective: The outcomes of fundoplication for gastroesophageal reflux disease are suboptimal in many children, and alternatives are clearly needed. Dextranomer hyaluronic acid (DxHA) copolymer, an agent with proven efficacy in vesicoureteral reflux, was studied with respect to its effects on the gastroesophageal junction (GEJ)., Methods: Twelve New Zealand white rabbits underwent measurement of lower esophageal sphincter pressure followed by laparotomy and injection into the muscular layer of the GEJ (controls, 1.0 mL saline; low-dose DxHA [0.5 mL]; high-dose DxHA [1.0 mL]). After a 12-week survival period, the animals underwent manometry, sacrifice, and necropsy. Organs were examined histologically by pathologists blinded to the injection delivered., Results: All animals survived. Weight gain was equal in the 3 groups. There was no significant difference in mean lower esophageal sphincter pressure from baseline in any group (control 2.3 mmHg [95% confidence interval, CI -3.3 to 7.9]; low-dose group 3.2 mmHg [95% CI -0.8 to 7.2]; high-dose group -4.0 mmHg [95% CI -18.95 to 10.95]). Histologically, DxHA injection produced an intramural implant, with a foreign body giant cell reaction, and fibroblastic infiltration with collagen deposition. High-dose injection did not consistently result in a qualitative increase in the magnitude of the reaction. There was no mucosal injury or luminal stenosis., Conclusions: In this first study evaluating the effects of DxHA injection at the GEJ, a histologic bulking effect was observed without obvious functional complications. The agent may have a role in the treatment of gastroesophageal reflux disease.

Objective: To evaluate the effects of cisapride and metoclopramide hydrochloride administered orally on the lower esophageal sphincter (LES) resting pressure in awake healthy dogs., Animals: 6 adult Beagles., Procedures: Each dog was evaluated after administration of a single dose of cisapride (0.5 mg/kg), metoclopramide (0.5 mg/kg), or placebo (empty gelatin-free capsule) in 3 experiments performed at 3-week intervals. To measure LES pressure, a high-resolution manometry catheter equipped with 40 pressure sensors spaced 10 mm apart was used. For each experiment, LES pressure was recorded during a 20-minute period with a virtual electronic sleeve emulation before treatment (baseline) and at 1, 4, and 7 hours after drug or placebo administration. A linear mixed-effects model was used to test whether the 3 treatments affected LES pressure differently., Results: In the cisapride, metoclopramide, and placebo experiments, median baseline LES pressures were 29.1, 30.5, and 29.0 mm Hg, respectively. For the cisapride, metoclopramide, and placebo treatments, median LES pressures at 1 hour after administration were 44.4, 37.8, and 36.6 mm Hg, respectively; median LES pressures at 4 hours after administration were 50.7, 30.6, and 31.1 mm Hg, respectively; and median LES pressures at 7 hours after administration were 44.3, 28.5, and 33.3 mm Hg, respectively. The LES pressures differed significantly only between the placebo and cisapride treatments., Conclusions and Clinical Relevance: Results suggested that orally administered cisapride may be of benefit in canine patients for which an increase in LES pressure is desirable, whereas orally administered metoclopramide did not affect LES resting pressures in dogs.

Objective: To measure intra-abdominal pressure (IAP) in horses that crib and compare it with IAP in horses that do not have this vice., Study Design: Cohort study., Animals: Healthy cribbing horses (cribbing cohort, n = 8) and 8 healthy noncribbing horses (noncribbing cohort)., Methods: A microsensor catheter was introduced into the peritoneal cavity through the right paralumbar fossa, using local anesthesia, for measurement of IAP. These pressures were recorded in 1-minute intervals for 2 hours, while the horses were standing tied in a stall. IAPs of cribbing horses were compared to the noncribbing cohort., Results: Baseline IAPs were not significantly different between cribbing and noncribbing cohorts (P = .076); however, IAPs in the cribbing cohort were significantly increased when compared with the noncribbing cohort, during active cribbing behavior (P = .0016). Frequency of cribbing was not associated with increased IAP (P = .35). IAPs in the cribbing cohort remained significantly elevated compared with the noncribbing cohort, even after the behavior had ceased (P = .0002)., Conclusion: Cribbing is associated with increased IAP in the horse, both during and after the behavior., (© Copyright 2013 by The American College of Veterinary Surgeons.)

Objective: To determine the effect of gastric distension on intraabdominal pressures (IAP) measured directly from the intraperitoneal space., Design: Prospective, experimental study., Setting: A university-based equine research facility., Animals: Ten healthy adult horses, 5 males and 5 females., Interventions: Intraabdominal pressures were measured through an intraperitoneal cannula zeroed at a height midway between the height of the tuber ishii and point of the shoulder at 6 time points: at rest, after placement of a nasogastric tube, and after instillation of each 5 L increment up to a total of 20 L of water. Simultaneously, mean arterial pressures (MAP) were obtained using a tail cuff, and abdominal perfusion pressures (APP) were calculated using the measured IAP minus the measured MAP., Measurements and Main Results: Baseline direct IAP measurements were subatmospheric (-4.5 ± 3.0 cm H2 O). IAPs were not significantly affected by placement of a nasogastric tube (-2.69, 95% CI [-3.24, -2.14], P = 0.4195), but were significantly increased after placement of 5 L (-1.73, 95% CI [-2.28, -1.18], P = 0.0015), 10 L (-0.54, 95% CI [-1.09,0.01], P = 0.0001), 15 L (0.89, 95% CI [0.34, 1.44], P = 0.0001), or 20 L (3.08, 95% CI [2.53, 3.63], P = 0.0001) of water into the stomach. APPs were not significantly different for any volume of fluid infused into the stomach (P = 0.05 for all comparisons)., Conclusion: IAPs were significantly increased when > 5 L of water was infused into the stomach. These results indicate the need for further research in clinical cases to determine the relationship between gastric pressures and the development of intraabdominal hypertension in horses., (© Veterinary Emergency and Critical Care Society 2013.)

Objective: To evaluate the use of high-resolution manometry (HRM) in awake and sedated dogs and to assess potential effects of a standard sedation protocol., Animals: 22 Beagles., Procedures: An HRM catheter with 36 pressure sensors was inserted intranasally in each dog. After an adaption period of 5 minutes, each set of measurements included 5 swallows of a liquid and 5 swallows of a solid bolus. Measurements were repeated 30 minutes after IM administration of buprenorphine and acepromazine., Results: HRM was successfully performed in 14 dogs. Data sets of 8 dogs were adequate for analysis. For the upper esophageal sphincter, median values of baseline pressure, residual pressure, relaxation time to nadir, and relaxation duration were determined for awake and sedated dogs for liquid and solid swallows. For the tubular portion of the esophagus, median values of peristaltic contractile integral, bolus transit time, and contractile front velocity were determined for awake and sedated dogs for liquid and solid swallows. For the lower esophageal sphincter, median values of baseline pressure and residual pressure were determined for awake and sedated dogs for liquid and solid swallows. Significant differences (awake vs sedated) were found for the upper esophageal sphincter residual pressure (liquid swallows), relaxation time to nadir (liquid swallows), bolus transit time (solid swallows), and contractile front velocity (solid swallows)., Conclusions and Clinical Relevance: HRM was feasible for evaluation of esophageal function in most awake dogs. Although sedation in uncooperative patients may minimally influence results of some variables, an overall assessment of swallowing should be possible.

Objective: To review and summarize the human and veterinary literature on intra-abdominal pressure measurement techniques., Data Sources: Human and veterinary clinical studies, research articles, reviews, and textbooks with no date restrictions with a focus on techniques for intra-abdominal pressure (IAP) measurement and their limitations., Human Data Synthesis: Human literature has established the intravesicular method as the gold standard for indirect measurement of IAP. However, current research has explored the intragastric method as a valid alternative. Recently, debate has focused on the shortcomings of the various measurement methods., Veterinary Data Synthesis: Early human literature using dogs as models contributed to the original data for IAP measurements in small animals. Since that time, a number of clinical studies and 1 case report have contributed to that original information. A reference interval for IAP measured by the intravesicular method has recently been determined in healthy cats., Conclusions: Further studies investigating IAP in critically ill veterinary patients are required to establish the optimal technique for this measurement in veterinary medicine., (© Veterinary Emergency and Critical Care Society 2012.)

Objectives: To determine whether direct intra-abdominal pressures (IAP) and calculated direct abdominal perfusion pressures (APP) are location dependent within the abdomen of standing horses. We hypothesize that IAP will be increased and calculated APP will be decreased at a ventral abdominal location (V) when compared to values obtained from the left (LFl) or right flank (RFl)., Design: Prospective experimental design., Setting: University-based equine research facility., Animals: Seven healthy adult horses, 4 geldings and 3 mares., Interventions: Measurements of direct IAP obtained from the RFl, LFl, and V locations via abdominal cannulation and direct arterial blood pressures obtained via catheterization of the transverse facial artery were obtained in fasted, standing, unsedated horses. APP was calculated for each location by the subtraction of IAP from the mean arterial pressure. Differences between sites of measurement for IAP, APP, and their gradients were calculated and compared by ANOVA and t-tests., Measurements and Main Results: Mean flank IAP measurements were subatmospheric and negative compared to ventral IAP values (LFl = -3 mm Hg, RFl = -5 mm Hg, V = 25 mm Hg; P < 0.001 between each flank and the ventral location). Ventrum APP was lower than flank APP (V = 82 mm Hg; LFl = 106 mm Hg; RFl = 108 mm Hg; P = 0.029 between each flank and the ventral location). Gradient calculations between sites showed the IAP increased and APP decreased from dorsal to ventral (P < 0.05) and from right to left (P = 0.004) within the abdomen., Conclusions: IAP and calculated APP are location dependent. These data provide new information regarding abdominal pressure profiles in standing healthy adult horses., (© Veterinary Emergency and Critical Care Society 2012.)

Objectives: To (1) evaluate intra-abdominal pressure (IAP) measurements in dogs with possible risk factors for the development of intra-abdominal hypertension (IAH); (2) determine intra-observer variability of IAP measurements; and (3) determine interobserver variability of IAP measurements., Design: Prospective, observational, pilot study., Setting: Veterinary teaching hospital., Animals: Fourteen client-owned dogs, requiring urinary catheterization, admitted to the ICU., Interventions: Using the risk factors for IAH established for human patients as defined by the World Society of Abdominal Compartment Syndrome, dogs were assigned to either an IAH risk or no risk group. A commercially available IAP monitoring system was used to obtain 3 direct, transvesical IAP measurements. The primary investigator obtained the first 2 IAP measurements. A secondary investigator obtained the third IAP measurement., Measurements and Main Results: Dogs in the IAH risk group (n = 9/14) had significantly higher mean IAPs (9.4 ± 3.4 mm Hg) than dogs in the no risk group (n = 5/14; 4.1 ± 0.9 mm Hg) (P < 0.05). Measurements recorded by the primary investigator were compared to determine intra-observer variability. Pearson's correlation coefficient was 0.98 (P < 0.0001). Bland-Altman analysis determined a mean difference in IAP measurements of -0.3 mm Hg (95% confidence interval from 0.13 to -0.71 mm Hg) indicating an intra-observer variability of less than 0.8 mm Hg. Measurements recorded by the primary and secondary investigator were compared to determine interobserver variability. Pearson's correlation coefficient was 0.95 (P < 0.0001). Bland-Altman analysis determined a mean difference in IAP measurements of 0 mm Hg (95% confidence interval from 1.1 to -1.1 mm Hg) indicating an interobserver variability of less than 2.0 mm Hg., Conclusions: Dogs with predefined human risk factors for IAH had higher IAP than dogs without risk factors. IAP monitoring appears to have low variability within and across observers., (© Veterinary Emergency and Critical Care Society 2012.)

Reasons for Performing Study: Standing laparoscopic procedures, facilitated by abdominal insufflation with carbon dioxide, are being employed to an increasingly greater extent in horses. However, a sustained increase in abdominal pressure may be life-threatening. A practical method for intra-abdominal pressure (IAP) assessment is imperative. Although indirect methods for estimating IAP have been extensively studied in man, little work has been performed in veterinary medicine., Objectives: To investigate the utility of gastric manometry for purposes of evaluating IAP in horses., Methods: Gastric pressure (P(ga) ) was estimated by balloon manometry in 8 healthy, mature horses, before and during a 30 min passive pneumoperitoneum induced by right paralumbar puncture. The balloon manometer was positioned within the gastric lumen and inflated using 2 separate volumes of air: 10 and 50 ml. P(ga) Gastric pressure was determined at baseline (0) and 5, 15 and 30 min after induction of passive pneumoperitoneum. Intra-abdominal pressure was measured directly by right paralumbar puncture using an 8 gauge needle at baseline and immediately following establishment of passive pneumoperitoneum., Results: Baseline IAP values were negative and increased (P≤0.05) during development of passive pneumoperitoneum. However, recorded P(ga) measurements for both inflation volumes were positive before (baseline) and during the course of the passive pneumoperitoneum. Measured P(ga) values did not correlate with IAP at any time., Conclusions and Potential Relevance: Our results suggest that the indirect method used in human patients for estimating IAP by P(ga) is not applicable for horses., (© 2011 EVJ Ltd.)

The objective of this study was to evaluate and validate the accuracy of the Perkins handheld applanation tonometer for measuring intraocular pressure (IOP) in horses and cattle. Both eyes of 10 adult horses and cattle were evaluated in a postmortem study. The eyes from 10 clinically normal adult horses and cattle were also examined after bilateral auriculopalpebral nerve block and topical anesthesia for an in vivo study. IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer). The correlation coefficients (r(2)) for the data from the postmortem manometry and Perkins tonometer study were 0.866 for horses and 0.864 for cattle. In the in vivo study, IOP in horses was 25.1 ± 2.9 mmHg (range 19.0~30.0 mmHg) as measured by manometry and 23.4 ± 3.2 mmHg (range 18.6~28.4 mmHg) according to tonometry. In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry. There was a strong correlation between the IOP values obtained by direct ocular manometry and the tonometer in both horses and cattle. Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.

To characterize primate arterial waveforms, we prospectively studied 38 bonnet macaques (Macaca radiata; 25 female, 13 ± 4 y). Brachial artery waveforms were recorded from these animals by applanation tonometry and were decomposed into harmonics by using Fourier analysis. The ratio of individual to total harmonic amplitude (H:T) was derived from frequency spectra. Left ventricular (LV) mass, ejection fraction, fractional shortening, septal wall thickness, posterior wall thickness, LV end-diastolic diameter, and LV end-systolic diameter were obtained by echocardiography in all 38 monkeys. Blood pressure was obtained by sphygmomanometry. The fundamental frequency was 2.76 cycles/s. Harmonics ranged from 5 to 14. Indexed LV mass was inversely correlated with third H:T and second H:T but not with systolic or diastolic blood pressure. In addition, the third H:T was inversely correlated with septal wall thickness, posterior wall thickness, and LV end-diastolic diameter, whereas second H:T was inversely correlated with LV end-diastolic diameter. Heart rate was inversely correlated with eighth H:T. On multivariate analysis adjusting for age, gender, weight, and length, only third H:T was an independent predictor of LV mass. Harmonic analysis of arterial waveforms may provide information pertaining to LV mass. Lower H:T ratios (second and third) are related to LV mass, whereas higher H:T (eighth) is related to heart rate.

Practical Relevance: the clinical importance of feline hypertension has been recognised for many years and most feline practitioners are quite familiar with this syndrome. Once systemic hypertension is identified, long-term management of the patient is needed to avoid catastrophic (eg, blindness due to retinal detachment) or subtle (eg, accelerated renal damage) target organ damage., Patient Group: feline systemic hypertension is most commonly a complication of renal disease and hyperthyroidism, both diseases of older feline patients. By 15 years of age, the probability of having at least one of these two diseases is high. As well cared for cats are living longer, optimal long-term management of feline hypertension in patients with concurrent diseases is an issue of clinical importance., Clinical Challenges: obtaining accurate blood pressure measurements in patients that are anxious, fractious or just plain uncooperative remains a significant issue in feline medicine, as does confident analysis of results from these patients., Diagnostics: careful measurement of systolic blood pressure using Doppler or oscillometric techniques in conjunction with evaluation for evidence of hypertensive choroidopathy (funduscopic examination) and hypertensive cardiac changes (thoracic auscultation) are essential to the diagnosis of systemic hypertension in cats. Other diagnostic techniques, including evaluation of renal and thyroid function, are needed to detect the underlying disease condition., Evidence Base: numerous well-designed clinical studies have greatly advanced our understanding of the most appropriate methods of diagnosis and therapy of feline hypertension.

Objective: To establish a reference interval for intra-abdominal pressure (IAP) measured by urinary bladder catheterization in normal cats and determine if IAP is affected by observer variation, volume of saline instillation before measurement, or subject variables of gender, positioning, body condition score, and sedation., Design: Prospective experimental study., Setting: Private referral center., Animals: Twenty healthy adult cats., Interventions: Sedation with butorphanol, midazolam, and propofol for catheterization of the urinary bladder and measurement of IAP., Measurements and Main Results: A 5-Fr red rubber urinary catheter was placed under sedation, and IAP was determined using a water manometer with the cats in right lateral and sternal recumbency. Three readings were taken in each position by 2 observers. The cats were allowed to recover with the urinary catheter in place, and IAP was measured in each cat while they were awake in right lateral and sternal recumbency., Conclusions: In this population of clinically healthy cats, median (interquartile range) IAP taken over all measurements was 7.00 cm H(2)O (5.23-8.83 cm H(2)O). There was no statistical difference between observers or subject gender. Factors associated with a statistically significant increase in IAP were right lateral compared with sternal recumbency (P=0.002), being awake compared with sedated (P<0.001), having a higher body condition score (P=0.01 and 0.001), instillation of a higher volume of saline into the bladder for measurement (P<0.001), and struggling during awake measurements (P<0.001).

Objective: To determine the accuracy of and to establish reference values for a rebound tonometer (Tonovet) in normal feline eyes, to compare it with an applanation tonometer (Tonopen Vet) and to evaluate the effect of topical anesthesia on rebound tonometry., Procedures: Six enucleated eyes were used to compare both tonometers with direct manometry. Intraocular pressure (IOP) was measured in 100 cats to establish reference values for rebound tonometry. Of these, 22 cats were used to compare rebound tonometry with and without topical anesthesia and 33 cats to compare the rebound and applanation tonometers. All evaluated eyes were free of ocular disease., Results: Both tonometers correlated well with direct manometry. The best agreement with the rebound tonometer was achieved between 25-50 mmHg. The applanation tonometer was accurate at pressures between 0 and 30 mmHg. The mean IOP in clinically normal cats was 20.74 mmHg with the rebound tonometer and 18.4 mmHg with the applanation tonometer. Topical anesthesia did not significantly affect rebound tonometry., Conclusions: As the rebound tonometer correlated well with direct manometry in the clinically important pressure range and was well tolerated by cats, it appears suitable for glaucoma diagnosis. The mean IOP obtained with the rebound tonometer was 2-3 mmHg higher than that measured with the applanation tonometer. This difference is within clinically acceptable limits, but indicates that the same type of tonometer should be used in follow-up examinations in a given cat.

Objectives: To develop a direct method for measuring intra-abdominal pressures in the standing horse, identify a reference interval for direct intra-abdominal pressures, compare these pressures to indirect intra-abdominal pressures measured from the bladder, and determine the optimal bladder infusion volume for indirect pressure measurement., Design: Prospective, experimental study., Setting: A university-based equine research facility., Animals: Ten healthy adult horses, 5 males and 5 females., Interventions: Direct intra-abdominal pressures were measured through an intraperitoneal cannula and zeroed at the height midway between the height of the tuber ishii and point of the shoulder. Indirect measurements of intra-abdominal pressure were performed by measuring intravesicular pressures through a transurethral catheter zeroed at the tuber ishii., Measurements and Main Results: Direct pressure measurements obtained in the standing horse were subatmospheric (mean, -1.80 cm H(2)O; SD, 1.61 cm H(2)O; 95% CI, -2.80 to -0.80) and were shown to decrease as the horse's weight increased (Pearson's r=-0.67, P=0.04), with no effect of head position (P=0.15). Mean baseline indirect pressure measurements (mean, -8.63 cm H(2)O; SD, 4.37 cm H(2)O; 95% CI, -13.05 to -4.21) were significantly different from the pressures measured directly from the abdomen (P<0.001). Indirect pressure measurements were noted to increase with increasing volumes infused into the bladder, and were statistically different at a volume of 100 mL (P=0.004). There was low to moderate correlation between direct and indirect pressure measurements of intra-abdominal pressure over a range of fluid volumes infused into the bladder (Pearson's correlation range -0.38 to 0.58)., Conclusion: Pressures measured directly in the standing horse were subatmospheric, and increased as the horse's weight increased. Indirect pressures measured were altered by increasing volumes infused in the bladder. There was no significant correlation between the 2 methods of intra-abdominal pressure measurement.

Reasons for Performing Study: Large colon resection and anastomosis (LCRA) is the most aggressive method of surgical management of a colon with questionable viability. Currently, published studies are comprised mostly of broodmares and discuss short-term survival., Objectives: To determine the prognosis for survival after LCRA in a diverse population of horses, report the incidence of post operative complications, and determine if associations between analysed variables and survival rate exist., Methods: The medical records of 52 horses that underwent LCRA were evaluated. Data were used to identify univariable associations with survival as well as complications related to LCRA. Chi-square, odds ratio with 95% confidence interval, Mann-Whitney or Kruskal-Wallis tests were used, with significance set at P<0.05., Results: Forty-four horses (84.6%) survived anaesthesia and recovery, 30 (57.7%) survived to be discharged from the hospital. Of the variables analysed, heart rate 24 h after recovery was significantly associated with mortality, as were endotoxaemia, ileus and peritonitis experienced post operatively., Conclusions: Heart rate 24 h after recovery may be a more reliable prognostic indicator than other analysed variables. Survival rate and complications after LCRA were similar to those previously reported.

Background: Gastric tonometry is commonly used in humans as an assessment of intestinal mucosal perfusion. Values in healthy foals are currently unknown., Hypothesis: Age, enteral feeding, and omeprazole administration would significantly alter gastric tonometry measurements in neonatal foals., Animals: Nine clinically normal foals were used to assess the effect of age and feeding, and 8 similar foals were used to assess the effect of omeprazole., Methods: At 1, 7, and 14 days of age, gastric intramucosal PCO2 (PgCO2) and arterial blood gas samples were obtained at baseline, immediately after feeding milk, and 1 and 2 hours after fasting for calculation of the intramucosal-arterial PCO2 difference (DeltaCO2). To evaluate the effect of omeprazole, foals were evaluated twice as above, 2 hours after fasting, comparing administration of omeprazole to no drug., Results: There was a significant effect of age and feeding on PgCO2 and DeltaCO2, whereas arterial PCO2 was not significantly affected by these factors. Postfeeding DeltaCO2 values were significantly lower than fasted values. Baseline and postfeeding DeltaCO2 increased with age. There was no significant effect of age on data collected after 1 or 2 hours of fasting. The 90% reference interval for DeltaCO2 data collected after fasting was 0-54 mmHg. Foals had a significantly higher mean gastric pH and significantly higher DeltaCO2 and PgCO2 following omeprazole relative to no treatment., Conclusions and Clinical Importance: Because of the high and variable DeltaCO2, which is exacerbated by omeprazole administration, the reference interval in foals is extremely wide.

Objective: To evaluate the relationship of colonic luminal pressure (CLP) measurements to outcome in horses with large colon volvulus (LCV) after either manual correction or large colon resection and anastomosis (LCRA)., Study Design: Retrospective study., Animals: Horses (n=57) that had LCV., Methods: Records for horses with LCV (March 1997-December 2003) were reviewed. Inclusion criteria were strangulating LCV proximal to the cecocolic ligament (>270 degrees), recorded CLP, and successful recovery from anesthesia. CLP measurements and survival/mortality rates were compared between horses that had manual correction (M) or LCRA (R)., Results: Of 57 horses, 27 had M and 30 had LCRA. For group M, CLP measurements had a sensitivity of 0.60 and specificity of 0.77 for predicting survival, whereas for group R, sensitivity was 0.50 and specificity was 0.54., Conclusion: In our LCV population, elevated CLP measurements had poor accuracy for predicting outcome in horses after surgical correction, especially after LCRA., Clinical Relevance: CLP measurements based on a single hospital population of horses with LCV should be used with caution for other hospital populations of LCV. CLP may be only one of many variables needed for predicting outcome of horses with strangulating LCV, especially after LCRA.

Objective: To evaluate changes in intraocular pressure and pupil size in glaucomatous dogs after instillation of 0.004% travoprost once in the morning, or once in the evening, or twice daily in 5-day multiple dose studies., Materials and Methods: Applanation tonometry (IOP) and pupil size (PS) measurements were obtained at 8 a.m., 10 a.m., 12 noon, 2 p.m. and 4 p.m. in eight glaucoma dogs. Methylcellulose (0.5% as placebo) was instilled in the control eye, and 0.004% travoprost was instilled in the opposite drug eye. Methylcellulose (0.5%) and 0.004% travoprost were instilled on the 2nd through to the 5th day with instillations in the morning (8.30 a.m.), or evening (8 p.m.), or twice daily (8.30 a.m. and 8 p.m.)., Results: The mean +/- SEM diurnal changes from baseline IOP in the control and placebo eyes in all three studies ranged from 1.2 +/- 0.3 mmHg to 3.2 +/- 0.9 mmHg. The mean +/- SEM diurnal changes from the baseline IOP after 0.004% travoprost at 8 a.m. once daily for the next 4 days were 19.0 +/- 2.7 mmHg, 24.7 +/- 2.7 mmHg, 24.9 +/- 3.1 mmHg, and 24.7 +/- 3.1 mmHg, respectively, and were significantly different from the control eye. After travoprost was instilled at 8 p.m., the mean +/- SEM baseline changes from the baseline IOP in the drug eyes were 23.5 +/- 2.2 mmHg, 24.2 +/- 2.2 mmHg, 24.5 +/- 2.3 mmHg, and 24.2 +/- 2.3 mmHg, respectively. When 0.004% travoprost was instilled twice daily, the mean +/- SEM baseline IOP changes were 27.7 +/- 2.1 mmHg, 28.1 +/- 2.1 mmHg, 28.4 +/- 2.2 mmHg, and 28.5 +/- 2.2 mmHg, respectively, and were significantly different from the control eyes. Miosis of varying duration was frequent during the three studies., Conclusion: Travoprost instilled once daily (a.m. or p.m.) as well as twice daily produces significant decreases in IOP and PS in the glaucomatous Beagle.

Objective: To determine intraocular pressure (IOP) in adult yellow-footed tortoises using applanation tonometry., Animals: Fifteen healthy adult captive yellow-footed tortoises (eight males and seven females)., Procedures: Intraocular pressures were estimated for tortoises by using an applanation tonometer after topical anesthesia. Body length, measured from nuchal to anal scutes, ranged from 27.5 to 57.2 cm. Five measurements from each eye were obtained by a single observer in an ambient temperature of approximately 30 degrees C., Results: Mean +/- SEM IOP of 30 eyes of 15 yellow-footed tortoises was 14.2 +/- 1.2 mmHg. Range of IOP was 6-30 mmHg for tortoises. Significant differences were detected neither between right and left eyes (P = 0.357) of individual tortoises, nor between males and females (P = 0.524). Observer's readability was good (intraclass coefficient = 0.65), and IOP did not change over the ordered five measurements., Conclusions: There was no significant difference in IOP between males and females in this specie. Tonometry values for normal eyes may represent a useful diagnostic methodology for recognition and treatment of ocular diseases in reptiles.

Aim: To study the relationship between the radiological anatomy and the dynamics on bile duct sphincter in bile draining and regularizing effect of gallbladder., Methods: Sixteen healthy dogs weighing 18 kg to 25 kg were divided randomly into control group and experimental group (cholecystectomy group). Cineradiography, manometry with perfusion, to effect of endogenous cholecystokinin and change of ultrastructure were employed., Results: According to finding of the choledochography and manometry, in control group the intraluminal basal pressure of cephalic cyclic smooth muscle of choledochal sphincter cCS was 9.0+/-2.0 mmHg and that of middle oblique smooth muscle of choledochal sphincter (mOS) was 16.8+/-0.5 mmHg, the intraluminal basal pressure of cCS segment was obviously lower than that of mOS (P<0.01) in the interval period of bile draining, but significative difference of intraluminal basal pressure of the mOS segment was not found between the interval period of bile draining (16.8+/-0.5 mmHg) and the bile flowing period (15.9+/-0.9 mmHg) (P>0.05). The motility of cCS was mainly characterized by rhythmically concentric contraction, just as motility of cCS bile juice was pumped into the mOS segment in control group. And motility of mOS segment showed mainly diastolic and systolic activity of autonomically longitudinal peristalsis. There was spasmodic state in cCS and mOS segment and reaction to endogenous cholecystokinin was debased after cholecystectomy. The change of ultrastructure of cCS portion showed mainly that the myofilaments of cell line in derangement and mitochondria is swelling., Conclusion: During fasting, the cCS portion has a function as similar cardiac "pump" and it is main primary power source in bile draining, and mOS segment serves mainly as secondary power in bile draining. The existence of the intact gallbladder is one of the important factors in guaranteeing the functional coordination between the cCS and mOS of bile duct sphincter. There is dysfunction in the cCS and mOS with cholecystectomy.

Objective: To compare effects of oxytocin, acepromazine maleate, xylazine hydrochloride-butorphanol tartrate, guaifenesin, and detomidine hydrochloride on esophageal manometric pressure in horses., Animals: 8 healthy adult horses., Procedure: A nasogastric tube, modified with 3 polyethylene tubes that exited at the postpharyngeal area, thoracic inlet, and distal portion of the esophagus, was fitted for each horse. Amplitude, duration, and rate of propagation of pressure waveforms induced by swallows were measured at 5, 10, 20, 30, and 40 minutes after administration of oxytocin, detomidine, acepromazine, xylazine-butorphanol, guaifenesin, or saline (0.9% NaCI) solution. Number of spontaneous swallows, spontaneous events (contractions that occurred in the absence of a swallow stimulus), and high-pressure events (sustained increases in baseline pressure of > 10 mm Hg) were compared before and after drug adminision., Results: At 5 minutes after administration, detomidine increased waveform amplitude and decreased waveform duration at the thoracic inlet. At 10 minutes after administration, detomidine increased waveform duration at the thoracic inlet. Acepromazine administration increased the number of spontaneous events at the thoracic inlet and distal portion of the esophagus. Acepromazine and detomidine administration increased the number of high-pressure events at the thoracic inlet. Guaifenesin administration increased the number of spontaneous events at the thoracic inlet. Xylazine-butorphanol, detomidine, acepromazine, and guaifenesin administration decreased the number of spontaneous swallows., Conclusions and Clinical Relevance: Detomidine, acepromazine, and a combination of xylazine butorphanol had the greatest effect on esophageal motility when evaluated manometrically. Reduction in spontaneous swallowing and changes in normal, coordinated peristaltic activity are the most clinically relevant effects.

Three dogs with dysuria and urine retention caused by excessive functional urethral resistance are described. All dogs had clinical histories and urologic signs that previously would have been classified as detrusor-urethral dyssynergia. Diagnosis of functional urinary obstruction was established by exclusion of anatomic urinary obstruction and confirmed by urethral pressure profilometry. In 2 cases, multiple pressure deflections recorded in the urethral pressure profile suggested spasm of urethral musculature, whereas in a 3rd dog, abnormally high pressures were recorded along a portion of the proximal urethra. Functional urinary obstruction was associated with prostatitis in 1 dog and with a history of urethral calculi in 1 dog, and no underlying disorder could be identified in the remaining dog. All 3 dogs improved with medical treatments that included alpha adrenergic antagonists. The etiology, diagnosis, and pharmacologic management of functional urinary obstruction are discussed.

The measurement of central venous pressure (CVP) will provide objective information about intravascular blood volume. Limitations exist with direct and indirect methods of measuring CVP; however, the purpose of this study was to determine if such factors as catheter size, patient position, or measurements taken with either a water manometer or a strain-gauge transducer would affect the accuracy of CVP measurements. The study population consisted of six adult, mixed-breed dogs. Catheter sizes evaluated were 16- and 19-gauge. Patient positions evaluated were right and left lateral recumbencies. Right atrial pressures (RAPs) were used as the reference standards for CVP measurements. Measurements of RAP and CVP were obtained with a water manometer and a strain-gauge transducer. No significant differences were observed in measured CVPs for the effects of catheter size and right versus left lateral recumbency. A 2.7-mmHg difference in water manometry was demonstrated when compared to strain-gauge transducer measurements. Also, strain-gauge transducer measurements had less precision compared to water manometer measurements.

The effect of body position on lower oesophageal sphincter pressure (LOSP), gastric pressure and barrier pressure (BrP) was investigated in 40 dogs anaesthetised for neutering procedures. The dogs were placed in lateral recumbency followed by dorsal recumbency (group 1) or vice versa (group 2). LOSP decreased significantly in the animals which were positioned initially in lateral recumbency, when they were then placed in dorsal recumbency, while those initially positioned in dorsal recumbency showed no significant change in their LOSP or BrP when their position was altered to lateral recumbency. When the data from both groups were pooled, LOSP and BrP were significantly lower when the dogs were in dorsal compared to lateral recumbency (P < 0.05).

Intra-abdominal pressure (IAP) was indirectly measured, using a transurethral catheterization technique, in 20 client-owned dogs before and after elective ovariohysterectomy. Mean preoperative IAP was 4.50 +/- 0.44 cm H2O. Elective abdominal surgery caused significant elevations in mean postoperative IAP (mean 7.50 +/- 0.45 cm H2O, range 0 to 15 cm H2O) that persisted for at least 24 hours. However, the increase in IAP caused no clinically evident complications; thus, after elective abdominal surgery an elevation in IAP up to 15 cm H2O is to be expected. Intra-abdominal pressure was also measured in 20 consecutive clinical cases with gross abdominal distension, before or after laparotomy, or both. Included in this group were dogs with gastric dilation and volvulus, closed pyometra, hemoperitoneum, acute ascites, and diaphragmatic hernias. All dogs with gross abdominal distension had an elevated IAP (> or = 16 cm H2O) either before or after surgery. Severe elevations of IAP were associated with anuria in two dogs, necessitating surgical decompression; one with hemoperitoneum (47 cm H2O) and one after repair of a chronic diaphragmatic hernia (30 cm H2O).

Fifty DSH cats were studied radiographically and a highly significant linear correlation was found between the length of the oesophagus measured to the diaphragmatic line on the radiographs and the externally measured distance from the lower jaw incisor teeth to the anterior border of the head of 10th rib. A subsequent manometric study utilizing this correlation in 40 cats suggests that the functional lower oesophageal sphincter (LOS) is situated almost at the level of the diaphragm in the cat. Significant differences were found between the length of the LOS in cats anaesthetized with ketamine compared to alphaxalone-alphadolone or xylazine-ketamine-atropine. The mean lengths of the LOS was 1.42 +/- 0.3 cm. The findings of this study indicate that external measurements can be used to position catheters for accurate oesophageal manometry in the cat.

Two Mackay-Marg tonometers and 2 Tono-Pen tonometers were evaluated in eyes in which intraocular pressure (IOP) had been altered and measured by use of a manometer. Eyes of anesthetized dogs and enucleated horse eyes were used. Compared with the manometer, none of the tonometers accurately measured IOP over the range between 0 and 100 mm of Hg. However at manometer measurements from 0 to 30 mm of Hg, several of the tonometers accurately measured IOP. In addition, significant differences were observed when the measurement accuracy of one tonometer was compared with that of another, especially at high IOP. Coefficient of determination (r2) values for a linear model ranged from 0.979 to 0.991 in dogs, and from 0.982 to 0.996 in horse eyes.

Intrahepatic postsinusoidal obstruction, similar to congenital Budd-Chiari syndrome in human patients, was diagnosed in a young Basenji dog. Sonographic, radiographic, and manometric studies were used in antemortem localization of this unusual functional lesion, that was believed to be congenital.

Comparisons of the MacKay-Marg and Tono-Pen applanation tonometers in open and closed in vitro systems were made for the eyes of cats. Both instruments significantly underestimated intraocular pressure (IOP) vs direct manometry (P less than 0.001), but in readily predictable manner, with high coefficients of determination (r2 = 0.99). For tonometer 1 (MacKay-Marg), calculated actual IOP = 1.36 x (MacKay-Marg measurement) - 1.67 mm of Hg; and for tonometer 2 (Tono-Pen), calculated actual IOP = 1.37 x (Tono-Pen measurement) + 0.8 mm of HG, using measurements from 11 enucleated eyes. In vivo comparisons were initially made in 81 clinically normal eyes (n = 41 cats) by applying the Tono-Pen first followed by the MacKay-Marg. Compared with the MacKay-Marg, the Tono-Pen significantly (P less than 0.001) underestimated IOP in these cats. When the order of tonometer applanation was subsequently reversed in 73 clinically normal eyes (n = 37 cats) the Tono-Pen again significantly (P less than 0.001) underestimated IOP, compared with the MacKay-Marg. Alterations in tonometer order did not result in significant differences in measured IOP for the MacKay-Marg when compared with itself, but Tono-Pen measurements were significantly (P less than 0.05) less when its use followed, rather than preceded, that of the MacKay-Marg. Mean (+/- SD) IOP in clinically normal cats when each tonometer was used first was 22.6 +/- 4.0 mm of Hg (range, 14 to 32 mm of Hg) for the MacKay-Marg and 19.7 +/- 5.6 mm of Hg (9 to 31 mm of Hg) for the Tono-Pen.(ABSTRACT TRUNCATED AT 250 WORDS)

Fifty dogs were investigated in order to correlate the length and position of the lower oesophageal sphincter (LOS) with external measurements. Various external measurements were taken while the dogs were anaesthetised and positioned in lateral recumbency. An oesophageal tube was then introduced into the oesophagus and thoracic radiographs were taken. The 'real internal length of the oesophagus' was calculated as the length from the lower jaw incisor tooth to the position of the oesophageal tube at the costal border of the diaphragm. A highly significant linear correlation was found between this internal length and the external length from lower jaw incisor tooth to the anterior border of the head of the 10th rib. Using oesophageal manometry, the length and position of the LOS was also studied in 25 clinically normal bitches. The mean length of the LOS was found to be 4.6 +/- 0.92 cm. The position of the LOS was a mean of 4.4 +/- 1.69 cm cranial to the costal border of the diaphragm. The findings of this study indicate that the external measurements can be used to position catheters for accurate oesophageal manometry in the dog.