Efficacy of Omeprazole versus High-Dose Famotidine for Prevention of Exercise-Induced Gastritis in Racing Alaskan Sled Dogs

Retrospective evaluation of the effect of acid suppressant drugs on leukocyte ratios in dogs with mast cell tumors

BACKGROUND

Acid suppressant drugs (ASDs) are commonly used to decrease gastric acid production, but some evidence exists that ASDs exert immunomodulatory effects. Such an effect has not been investigated in dogs for which ASDs are routinely prescribed.

HYPOTHESIS

Compared to naïve subjects, dogs treated with ASDs will exhibit differences in leukocyte ratios after treatment.

ANIMALS

Fifty-one dogs with mast cell tumors (MCTs).

MATERIALS AND METHODS

Dogs with MCT that were either AS naïve or treated with ASDs (i.e., histamine-2-receptor antagonists [H2RA] or proton pump inhibitors [PPI]) were included in this retrospective study. Subjects were categorized into 3 treatment groups (AS naïve, H2RA treated, and PPI treated), and leukocyte ratios (neutrophil:eosinophil, lymphocyte:monocyte, and neutrophil:lymphocyte [NLR]) were calculated before and after treatment. A mixed effects analysis of variance on ranks was used to assess differences in ratios between treatments, between pre- and post-treatment time points, and between pre- and post-time points for each treatment. Concurrent administration of antihistamines, corticosteroids, and chemotherapeutic drugs was assessed as a confounding factor.

RESULTS

Famotidine (n = 14/14) and omeprazole (n = 12/12) were the only H2RA and PPI used, respectively. Dogs receiving famotidine had a significant increase in median NLR from pre- to post-treatment (3.429; range, 1.417-15 to 5.631; range, 2.654-92; P < 0.01) compared to PPI treated or AS naïve dogs. No differences existed in chemotherapeutic drug or corticosteroid use between groups.

CONCLUSIONS

A significant difference in NLR was identified in famotidine treated dogs compared with omeprazole treated or AS naïve dogs.

Prevalence and appropriateness of omeprazole prescription in dogs at a veterinary teaching hospital before and after the publication of the ACVIM consensus statement on the rational administration of gastrointestinal protectants

Introduction

Overprescribing of acid suppressants is a common phenomenon in human and small animal patients, leading to potential deleterious gastrointestinal (GI) and non-GI consequences. The impact of consensus statements on veterinary prescribing habits in clinical practice have not been fully evaluated. This study aimed to compare the prescribing habits of the proton pump inhibitor (PPI), omeprazole, in dogs in an academic veterinary teaching hospital before and after the publication of the American College of Veterinary Internal Medicine (ACVIM) consensus statement on rational use of gastrointestinal protectants.

Methods

Evaluation of the prescribing habits of omeprazole in dogs during the years 2017 and 2021 was retrospectively compared. These years were selected to reflect a 12-month period prior to and following the publication of the consensus statement. One hundred dogs from each year were randomly selected. Dose, frequency of administration, duration of treatment, concurrent prescription of more than one gastroprotectant and indications for prescribing omeprazole were analyzed.

Results

A significant increase in the cases that received omeprazole q12h (p < 0.0001) or that underwent a tapering dose after ≥4 week-therapy (p > 0.0001) was detected after the publication of the 2018 ACVIM consensus statement. Considering the indications, there was also a significant increase in the appropriate prescription of omeprazole in the second compared to the first period of study (p < 0.0001). Fifteen of 16 clinicians (94%) involved in the prescription of omeprazole indicated that their reading of the consensus statement had changed their clinical practice regarding PPI administration in dogs.

Discussion

These results support the beneficial impact of the ACVIM consensus statement on the judicious prescribing of omeprazole in an academic veterinary hospital. These results should not be extrapolated to first-opinion veterinary practices, and further efforts should be made to ensure that PPIs are prescribed prudently with a clear indication and regular review of the appropriateness of continued administration to minimize possible risks and adverse drug interactions.

Prospective Randomized Controlled Clinical Trial of the Long-Term Effects of Omeprazole on Healthy Dogs

The use of omeprazole as a preventive treatment for gastrointestinal ulcers in veterinary medicine has been questioned during previous years. The aim of the present study is to assess the long-term effect of omeprazole on cobalamin and serum gastrin levels in healthy dogs. Eighteen healthy dogs were included: 10 in the control group and 8 in the omeprazole group. Three samples were collected: before starting the treatment (T0), 30 days after the start of treatment (T1), and at 60 days (T2). The mean cobalamin value (ng/L) in the control group was 481.4 (±293.70) at T0, 481.4 (±170.21) at T1, and 513.2 (±174.50) at T2. In the omeprazole group, the values were 424.62 (±161.57) at T0, 454.5 (±160.96) at T1, and 414.87 (±127.90) at T2. No statistically significant changes were detected in cobalamin levels between the three-time period in both study groups. These results agree with previous findings in felines but contrast with human medicine studies. The median gastrin values (pg/mL) in the control group were 62.45 [30.17-218.75] at T0, 76.06 [30.67-199.87] at T1, and 63.02 [35.81-176.06] at T2. The median gastrin value in the omeprazole group was 67.59 [55.96-101.60] at T0, 191.77 [75.31-1901.77] at T1, and 128.16 [43.62-1066.46] at T2. Statistically significant differences were detected (p = 0.008), indicating an increase in gastrin levels after initiating treatment with omeprazole. In conclusion, the increased levels of gastrin observed in this population underscore the importance of conducting a comprehensive clinical assessment to identify potential gastrointestinal disorders, particularly in consideration of the usage of omeprazole as a preventive treatment.

Effect of esomeprazole with and without a probiotic on fecal dysbiosis, intestinal inflammation, and fecal short-chain fatty acid concentrations in healthy dogs

BACKGROUND

Proton pump inhibitors can cause diarrhea and a transient increase in fecal dysbiosis index in dogs. It is unknown if concurrent probiotic administration mitigates these effects.

OBJECTIVE/HYPOTHESIS

To assess the fecal Canine Microbial Dysbiosis Index (CMDI), fecal short chain fatty acid (SCFA), and fecal calprotectin concentrations in dogs administered esomeprazole with and without a probiotic.

ANIMALS

Eleven healthy dogs.

METHODS

Prospective, within-subjects before and after study. All dogs received 7-day courses of esomeprazole (1 mg/kg PO q 24h) alone followed by esomeprazole with a probiotic (15 billion CFU/kg), separated by a 4-week washout period. Data were compared between phases using mixed effects ANOVA or generalized estimating equations with post-hoc Holm adjustment for 2-way comparisons.

RESULTS

Compared to baseline (mean CMDI -2.66, SD 3.04), fecal CMDI was not different with esomeprazole administration alone (mean CMDI -1.48, SD 3.32, P = .08), but there was a significant increase (Diff 3.05, 95% CI [1.37, 4.74], P < .001, Effect size 2.02) when esomeprazole and a probiotic were administered concurrently (mean CMDI 0.39, SD 2.83). CMDI was significantly higher when esomeprazole was administered with a probiotic than alone (Diff 1.87, 95% CI [0.19, 1.87], P = .02, Effect size 1.24). Fecal calprotectin and SCFA concentrations did not differ between phases. The occurrence of vomiting and diarrhea was not different from baseline when esomeprazole was administered alone (36%/27%) or with a probiotic (46%/9%).

CONCLUSIONS AND CLINICAL IMPORTANCE

In healthy dogs, concurrent administration of a probiotic is unlikely to lessen adverse effects associated with esomeprazole administration.

Assessment of gastrointestinal health in racing Alaskan sled dogs using capsule endoscopy and inflammatory cytokines

OBJECTIVES

Exercise-induced gastrointestinal syndrome occurs in dogs and people and might compromise athlete performance by increasing intestinal permeability and causing gastrointestinal erosions. Racing sled dogs often receive acid suppressant prophylaxis which decreases the incidence of gastric erosions induced by exercise. The objectives were to quantify intestinal injury by measuring serum pro-inflammatory cytokine concentrations before and after exercise and to evaluate gastrointestinal mucosa using video capsule endoscopy after exercise.

MATERIALS AND METHODS

Prospective study of 12 racing Alaskan sled dogs receiving approximately 1 mg/kg omeprazole once daily from the day before the race until race completion. Blood was drawn before and 8 to 10 hours after an endurance race for the quantification of cytokines. Gastrointestinal tract mucosa was assessed with video capsule endoscopy immediately post-race.

RESULTS

Eight of nine dogs (89%; 95% confidence interval 52 to 100%) had gastric erosions; all dogs (100%, 95% confidence interval 63 to 100%) had small intestinal erosions. Most of the dogs (seven of nine) had straw or foreign material present. Cytokine levels were not different from before to after the race.

CLINICAL SIGNIFICANCE

Video capsule endoscopy identified gastrointestinal tract mucosal erosions after exercise in all dogs receiving once-daily omeprazole treatment, though other causes for the lesions besides exercise are possible.

Prescribing habits for the use of omeprazole as a gastroprotectant in dogs in a veterinary teaching hospital

OBJECTIVES

To examine the prescribing habits for omeprazole in a veterinary teaching hospital and to evaluate the effect of a clinical audit on omeprazole prescription.

MATERIAL AND METHODS

Observational study with retrospective clinical audit followed by a prospective study. The evaluated data about omeprazole prescription included the dose, frequency and indication. These were assessed according to published guidelines. A seminar about the audit and current guidelines on the use of omeprazole was organised for all members of clinical staff. Prospective data collection was conducted after the seminar. A comparison of the collected data before and after the clinical audit was made.

RESULTS

A total of 301 dogs were prescribed omeprazole in the veterinary teaching hospital during the study period (including the retrospective and prospective parts). Complete data were acquired from 240 patients. The prescribed frequency of omeprazole was inappropriate in 23 (16.5%) of the prescriptions in the retrospective section but in only five (5.0%) in the prospective study. Inappropriate indications were reported in 12 (8.6%) patients in the retrospective section and in two patients (2.0%) in the prospective study. Overall inappropriate omeprazole prescription was identified in 34 (24.5%) patients in the retrospective part and in seven (6.9%) patients in the prospective part. There was a statistically significant difference between the two groups in frequency, indication and overall prescription of omeprazole.

CLINICAL SIGNIFICANCE

This study details the frequency of inappropriate prescription of omeprazole in a veterinary teaching hospital and provides some evidence that dissemination of guidelines based on clinical audit can improve prescribing habits.

Use of a videofluoroscopic feeding evaluation to guide management of dogs with congenital idiopathic megaoesophagus

Background

Evidence‐based guidelines for determining dietary management in dogs with megaoesophagus are lacking.

Objectives

This study looked to compare oesophageal clearance times (ECT) of liquid and two food consistencies using a contrast videofluoroscopy feeding evaluation, and to assess if recommendations made based on findings could improve regurgitation and quality of life in dogs with congenital megaoesophagus.

Methods

Twenty‐one dogs with congenital megaoesophagus and nine healthy dogs received liquid, slurry, and meatball diets containing barium while in an upright position. Follow‐up was performed to determine response to recommendations.

Results

Healthy dogs had significantly shorter median ECT for all consistencies (p < 0.001). In the megaoesophagus group, ECT varied by consistency and individual. The number of dogs in the megaoesophagus group with complete clearance was four (median ECT 10 min) for liquid, five (median ECT 5 min) for slurry, and two (median ECT 5 and 30 min, respectively) for meatballs. Partial clearance was seen in 11 dogs (median clearance 25%) with liquid, seven with slurry (median clearance 50%), and five with meatballs (median clearance 60%). Recommendations included altering current medications (13/21 dogs), diet consistency (6/21), time upright (12/21), water delivery (21/21), and adding activity (7/21). Regurgitation episodes/week decreased significantly from 5.5 to 2.5 (p < 0.001) at follow‐up 3–5 weeks post‐evaluation, with 95% of owners reporting improvement in quality of life. Seventy percent were alive 46–777 days after last recheck. Three dogs died from megaoesophagus associated complications (median survival 461 days after diagnosis).

Conclusions

The findings of this study suggest that a videofluoroscopic feeding evaluation may help guide management of dogs with congenital megaoesophagus.

Efficacy of Nx4 to Reduce Plasma Cortisol and Gastrin Levels in Norwegian Sled Dogs During an Exercise Induced Stress Response: A Prospective, Randomized, Double Blinded, Placebo-Controlled Cohort Study

Introduction: An exercise induced stress response is commonly seen in high performance sled dogs, resulting in increased plasma cortisol. A stress induced rise of cortisol might result in increased prevalence of gastritis and gastric ulcers mediated by an increase of gastrin. Neurexan^® (Nx4) is a medicinal product used for stress relief by reduction of cortisol. The aim of the study was to show that Nx4 reduces plasma cortisol and plasma gastrin in high performance sled dogs and to show tolerability of Nx4 in dogs.

Material and Methods: First, a pilot study was done to validate the increase of cortisol by performance. The data from the pilot study was used for sample size estimation via an adapted power analysis as well as the identification of important variables. These were then used in the randomization procedure of the main study. Second, a prospective randomized, double blinded, placebo-controlled cohort study was conducted. The main study included 45 sled dogs, assigning 23 dogs to the Nx4 group, and 22 dogs to the placebo group, to analyze plasma cortisol and plasma gastrin at four time points: before, directly after and 30 and 120 min after performance.

Results: For the main target variable, area under the curve (AUC) of plasma cortisol, a significantly lower adjusted mean value in the Nx4 group compared to the placebo group (p = 0.031) was found. Plasma gastrin was also significantly reduced in the Nx4 group 30 min after performance (p = 0.023), resulting in a significantly reduced plasma gastrin AUC in the Nx4 group compared to the placebo group (p = 0.049).

Discussion: Within the limitation of the study, the results carry implications for the usefulness of Nx4 to reduce exercise induced plasma cortisol and gastrin levels. The reduction of the exercise induced stress response could help to improve the welfare of high-performance sled dogs. Since activation of the hypothalamic-pituitary-adrenal axis resulting in increased cortisol is similar for exercise induced stress and psychologic stress, the same might be true independent of the stressor, making Nx4 potentially useful in any stressful situation for dogs.

A prospective, randomized, placebo-controlled, double-blinded clinical trial comparing the incidence and severity of gastrointestinal adverse events in dogs with cancer treated with piroxicam alone or in combination with omeprazole or famotidine

OBJECTIVE

To assess the impact of prophylactic omeprazole and famotidine on the incidence and severity of gastrointestinal (GI) adverse events (AEs) in dogs with cancer treated with single agent piroxicam.

ANIMALS

39 dogs with a cytologic or histologic diagnosis of cancer with no history of GI disease and received piroxicam.

PROCEDURES

A prospective, randomized, placebo-controlled, double-blinded clinical trial was performed. All dogs received piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h) and either omeprazole (1 mg/kg [0.45 mg/lb], PO, q 12 h), famotidine (1 mg/kg, PO, q 12 h), or placebo (lactose; PO, q 12 h). Monthly assessments of GI AEs were performed and scored by using the Veterinary Comparative Oncology Group's Common Terminology Criteria for Adverse Events (version 1.1).

RESULTS

Compared with dogs in the placebo group, more dogs in the omeprazole group (84.6% vs 36.4%) and famotidine group (80.0% vs 36.4%) experienced GI AEs by day 56. The severity of GI AEs was higher in the omeprazole group, compared with the placebo group.

CONCLUSIONS AND CLINICAL RELEVANCE

Omeprazole was not helpful in reducing the frequency or severity of GI AEs and was associated with more frequent and severer GI AEs in dogs with cancer treated with single agent piroxicam. Proton-pump inhibitors and H2-receptor antagonists should not be prescribed as prophylaxis with NSAIDs for dogs with cancer.

Survey-Based Analysis of Current Trends for Prescribing Gastrointestinal Protectants among Small-Animal General Practitioners in Portugal

In both human and veterinary healthcare, gastrointestinal protectants (GIPs) are considered a staple of clinical practice in that they are prescribed by general practitioners (GPs) and specialists alike. Concerning GIP use, overprescription of proton pump inhibitors (PPIs) has become a growing concern among human healthcare providers. This trend has also been documented within veterinary practice, prompting the American College of Veterinary Internal Medicine (ACVIM) to publish a consensus statement in 2018 concerning evidence-based indications for GIP use. This observational cross-sectional study evaluated self-reported prescribing protocols among Portuguese GPs to determine whether there is adherence to the consensus guidelines. Respondents were Portuguese GPs recruited by social media posts in veterinarian online forums. Data were collected from 124 respondents concerning their GIPs of choice and their rationales for prescribing them. Data were mined for prescription patterns and protocols. Among GIPs, PPIs were prescribed more often. Rationales for use included gastrointestinal ulceration and erosion (GUE), prophylactic management of nonerosive gastritis, pancreatitis, reflux esophagitis, and steroid-induced ulceration. Once-daily administration of PPIs was the most frequent dosing regime among respondents. Ninety-six percent of PPI prescribers advocated that the drug be administered either shortly before or at mealtime. Forty-nine percent of respondents supported long-term use of PPIs. Fifty-nine percent of respondents acknowledged discontinuing PPIs abruptly. This study supports that Portuguese GPs commonly prescribe GIPs in accordance with ACVIM recommendations to medically manage GUE. However, misuse of GIPs does occur, and they have been prescribed where their therapeutic value is debatable. Educational strategies should target GPs in an effort to reduce GIP misuse.

Gastroprotective Therapy

A range of gastroprotective drugs are available for the treatment of esophagitis and gastroduodenal mucosal injury including acid suppressants (ie, histamine-2 receptor antagonists, proton pump inhibitors), coating agents, prostaglandin analogs, and antacids. Of these, the proton pump inhibitors are the most effective drugs for the medical treatment of upper gastrointestinal injury. However, proton pump inhibitors are not effective for all causes of upper gastrointestinal injury. The choice of gastroprotective drug should be guided by the cause and location of gastrointestinal injury and the potential for adverse effects.

ACVIM consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats

The gastrointestinal (GI) mucosal barrier is continuously exposed to noxious toxins, reactive oxygen species, microbes, and drugs, leading to the development of inflammatory, erosive, and ultimately ulcerative lesions. This report offers a consensus opinion on the rational administration of GI protectants to dogs and cats, with an emphasis on proton pump inhibitors (PPIs), histamine type-2 receptor antagonists (H2 RAs), misoprostol, and sucralfate. These medications decrease gastric acidity or promote mucosal protective mechanisms, transforming the management of dyspepsia, peptic ulceration, and gastroesophageal reflux disease. In contrast to guidelines that have been established in people for the optimal treatment of gastroduodenal ulcers and gastroesophageal reflux disease, effective clinical dosages of antisecretory drugs have not been well established in the dog and cat to date. Similar to the situation in human medicine, practice of inappropriate prescription of acid suppressants is also commonplace in veterinary medicine. This report challenges the dogma and clinical practice of administering GI protectants for the routine management of gastritis, pancreatitis, hepatic disease, and renal disease in dogs and cats lacking additional risk factors for ulceration or concerns for GI bleeding. Judicious use of acid suppressants is warranted considering recent studies that have documented adverse effects of long-term supplementation of PPIs in people and animals.

Effects of Short-Distance Recreational Mushing on Oxytocin, Gastrin, and Creatinine Kinase in Sled Dogs

A considerable increase in creatinine kinase (CK) activity and gastrin hormone due to exercise has been observed in sled dogs during endurance mushing races; however, there have been no studies on sled dogs during recreational mushing. Although oxytocin hormone is involved in social behaviors and empathy, it has not been studied in sled dogs. This study aimed to assess changes in plasma CK activity, and gastrin and oxytocin concentrations in adult sled dogs used in touristic mushing in North Patagonia, Argentina. Blood samples were collected before, during, and after the winter season of 2017. Creatinine kinase activity measurement was done using an enzymatic assay. Hormone analyses were performed using commercial Enzyme-Linked InmunoSorbent Assay kits. Results showed an expected two-fold increase in CK activity during the winter, with recovering basal values after winter (< 400 UI/L), low and stable levels of gastrin (9.4 ± 8.8 pg/mL), and a slight increase in oxytocin (23%) after mushing activities. No evidence indicated gastrin alterations or muscular damage from touristic mushing, but an oxytocin increase would indicate a stimulation of the brain reward system.

Gastroduodenal Ulceration in Small Animals: Part 2. Proton Pump Inhibitors and Histamine-2 Receptor Antagonists

In the first part of this review, we discussed the pathophysiology and epidemiology of gastric acid secretion and the epidemiology of gastroduodenal ulceration in dogs and cats. In this section, we discuss the pharmacology and evidence-based clinical use of histamine-2 receptor antagonists and proton pump inhibitors.

Pharmacokinetics of esomeprazole following intravenous and oral administration in healthy dogs

Investigation into the pharmacokinetic profile of esomeprazole was conducted using eight healthy dogs after intravenous (IV) and oral (po) administration in a two-part randomized crossover study. The dogs were fasted for a minimum of 12 hours and then received esomeprazole either intravenously (dose range 0.93–1.48 mg/kg) or orally using an enteric-coated formulation (dose range 0.95–1.50 mg/kg). After a 1-week washout period, the dogs received an alternative treatment. Serial blood samples were collected at predetermined time points, and plasma esomeprazole concentrations were determined by using ultra-high-performance liquid chromatography–mass spectrometry. Noncompartmental pharmacokinetic analyses were performed. Then, the area under the plasma concentration/time curve (AUC) and maximal plasma concentration (C_max) values were normalized to a 1.0 mg/kg dose of esomeprazole, that is, AUC/dose. Median (range) dose-normalized peak plasma concentration (C_max) values for the IV and po formulations were 4.06 µg/mL (2.47–4.57 µg/mL) and 1.04 µg/mL (0.31–1.91 µg/mL), respectively. The median (range) time-to-peak concentration (T_max) for the po formulation was 105 minutes (45–360 minutes). Median (range) plasma terminal half-life (t_½) was 45.56 minutes (39.43–64.20 minutes) for the IV formulation and 63.97 minutes (44.02–109.94 minutes) for the enteric-coated po formulation. The median (range) po bioavailability was 63.33% (32.26%–79.77%). Clinically, both po and IV formulations were well tolerated with minimal side effects observed.

Serum concentration of gastrin, cortisol and C-reactive protein in a group of Norwegian sled dogs during training and after endurance racing: a prospective cohort study

Background

High incidences of gastritis and gastric ulceration are observed in sled dogs participating in endurance races. Exercise-induced increases in hormones like gastrin and cortisol have been suggested as possible contributing factors. An increase in C-reactive protein (CRP) has also been observed in canines during physical exercise. The aim of this study was to evaluate the effect of long distance racing on the serum concentration of gastrin, cortisol and CRP in a group of sled dogs, by comparing the results achieved early in the training season and after participating in a long distance race; “Femundløpet”. Dogs that only trained to the race, but did not compete in the race, were used as control dogs. Sixty-five sled dogs participated in the study; 46 competing dogs (25 completing and 21 non-completing the race) and 19 non-racing dogs (control dogs). The blood samples were collected in October 2012 and February 2013.

Results

The post-race serum concentration of gastrin, cortisol and CRP was significantly elevated in sled dogs participating in the race (both completing and non-completing dogs) when compared to the results from training. However, no significant differences were observed between the two sampling dates in the control dogs. Post-race results for completing and non-completing dogs were also compared. This demonstrated a significant elevation in gastrin in non-completing versus completing dogs, and a significant elevation in cortisol in completing compared to non-completing dogs.

Conclusions

Participation in a long distance race was associated with a significant increase in serum gastrin, cortisol and CRP in sled dogs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-016-0204-9) contains supplementary material, which is available to authorized users.

Gastritis and Gastric Ulcers in Working Dogs

Gastritis and gastric ulcers are an important cause of morbidity and mortality in canine athletes. Although the majority of scientific work on this condition has been performed in ultraendurance racing sled dogs, this condition has been identified in other canine athletes, including sled dogs competing in shorter events and dogs performing off-leash explosive detection duties. The cause of the syndrome is unknown, but current hypotheses propose a link between exercise-induced hyperthermia and loss of gastric mucosal barrier function as an early event in the pathogenesis. Treatment is focused on prevention of clinical disease using acid secretion inhibitors, such as omeprazole, which has excellent efficacy in controlled clinical studies.

A Prospective, Placebo-Controlled Pilot Evaluation of the Effect of Omeprazole on Serum Calcium, Magnesium, Cobalamin, Gastrin Concentrations, and Bone in Cats

BACKGROUND

Chronic proton pump inhibitor administration has been associated with electrolyte and cobalamin deficiency, disrupted bone homeostasis, hypergastrinemia, and rebound acid hypersecretion in humans. It is unknown if this occurs in cats.

OBJECTIVES

Prolonged oral omeprazole results in altered bone mineral density or content, serum calcium, magnesium, cobalamin, and gastrin concentrations in healthy cats.

ANIMALS

Six healthy adult DSH cats.

METHODS

In a within subjects, before and after design, cats received placebo followed by omeprazole (0.83-1.6 mg/kg PO q12h) for 60 days each. Analysis of serum calcium, magnesium, cobalamin, and gastrin concentrations was performed on days 0, 30, and 60. Bone density and content were evaluated on days 0 and 60 of each intervention. Continuous data were analyzed using a two-way ANOVA (α = 0.006). On day 60 of omeprazole administration, continuous intragastric pH monitoring was performed in 2 cats to evaluate the effects of abrupt withdrawal of omeprazole.

RESULTS

No significant changes were detected between treatments for any variables, except serum gastrin, which was significantly higher during omeprazole treatment in comparison to placebo (P = 0.002). Evidence of gastric hyperacidity was seen in both cats in which intragastric pH monitoring was performed following cessation of omeprazole.

CONCLUSIONS AND CLINICAL IMPORTANCE

Although further studies with larger populations of cats will be needed to draw any definitive conclusions, these preliminary results suggest that prolonged PPI treatment results in hypergastrinemia and abrupt PPI withdrawal might result in RAH in cats.

The effect of orally administered ranitidine and once-daily or twice-daily orally administered omeprazole on intragastric pH in cats

BACKGROUND

Gastric acid suppressants frequently are used in cats with acid-related gastric disorders. However, it is not known if these drugs effectively increase intragastric pH in cats.

OBJECTIVES

To examine the effects of PO administered ranitidine and omeprazole on intragastric pH in cats and to compare the efficacy of once-daily versus twice-daily dosage regimens for omeprazole.

ANIMALS

Eight domestic shorthair cats.

METHODS

Using a randomized 4-way cross-over design, cats were given enteric-coated omeprazole granules (1.1-1.3 mg/kg q24h and q12h), ranitidine (1.5-2.3 mg/kg q12h), and placebo. Intragastric pH was monitored continuously for 96 hours using the Bravo(™) system, starting on day 4 of treatment, followed by a median washout period of 12 days. Mean percentage of time pH was ≥3 and ≥4 was compared among groups using repeated measures ANOVA.

RESULTS

Mean ± SD percentage of time intragastric pH was ≥3 and ≥4 was 67.0 ± 24.0% and 54.6 ± 26.4% for twice-daily omeprazole, 24.4 ± 22.8% and 16.8 ± 19.3% for once-daily omeprazole, 16.5 ± 9.0% and 9.6 ± 5.9% for ranitidine, and 9.4 ± 8.0% and 7.0 ± 6.6% for placebo administration. Twice-daily omeprazole treatment significantly increased intragastric pH, whereas pH after once-daily omeprazole and ranitidine treatments did not differ from that of placebo-treated cats.

CONCLUSION AND CLINICAL IMPORTANCE

Only twice-daily PO administered omeprazole significantly suppressed gastric acidity in healthy cats, whereas once-daily omeprazole and standard dosages of ranitidine were not effective acid suppressants in cats.

Efficacy of intravenous administration of combined acid suppressants in healthy dogs

Background

Short‐term intravenous co‐administration of famotidine and pantoprazole is used by some veterinarians to treat gastrointestinal bleeding in critically ill dogs. However, clinical studies have not evaluated the efficacy of combination acid suppressant treatment in dogs.

Hypothesis/Objectives

To compare the effect of intravenous co‐administration of famotidine and pantoprazole to monotherapy with pantoprazole on intragastric pH in dogs. We hypothesized that single agent pantoprazole would be more effective than combination with famotidine.

Animals

Twelve healthy adult colony dogs.

Methods

Randomized, 2‐way crossover design. All dogs received placebo (0.9% saline) for 24 hours followed by 1.0 mg/kg IV q12h pantoprazole or combination treatment with famotidine and pantoprazole for 3 consecutive days. Intragastric pH monitoring was used to continuously record intragastric pH for 96 hours beginning on day 0 of treatment. Mean percentage time (MPT) that intragastric pH was ≥3 and ≥4 were compared between groups using ANOVA with a posthoc Tukey‐Kramer test (α = 0.017).

Results

The MPT ± standard deviation intragastric pH was greater than ≥3 and 4 were 79 ± 17% and 68 ± 17% for pantoprazole and 74 ± 19% and 64 ± 23% for combination treatment, respectively. There were no significant differences in MPT intragastric pH was ≥3 and 4 between groups. Pantoprazole administered alone achieved pH goals established for humans with acid‐related disorders.

Conclusions and Clinical Importance

These results suggest that short‐term combination treatment with famotidine and pantoprazole is not superior to pantoprazole alone for increasing intragastric pH in dogs.

Evaluation of the effect of orally administered acid suppressants on intragastric pH in cats

Background

Acid suppressant drugs are a mainstay of treatment for cats with gastrointestinal erosion and ulceration. However, clinical studies have not been performed to compare the efficacy of commonly PO administered acid suppressants in cats.

Hypothesis/Objectives

To compare the effect of PO administered famotidine, fractionated omeprazole tablet (fOT), and omeprazole reformulated paste (ORP) on intragastric pH in cats. We hypothesized that both omeprazole formulations would be superior to famotidine and placebo.

Animals

Six healthy adult DSH colony cats.

Methods

Utilizing a randomized, 4‐way crossover design, cats received 0.88–1.26 mg/kg PO q12h fOT, ORP, famotidine, and placebo (lactose capsules). Intragastric pH monitoring was used to continuously record intragastric pH for 96 hours beginning on day 4 of treatment. Plasma omeprazole concentrations at steady state (day 7) were determined by high performance liquid chromatography (HPLC) with ultraviolet detection. Mean percentage time that intragastric pH was ≥3 and ≥4 were compared among groups using ANOVA with a posthoc Tukey‐Kramer test (α = 0.05).

Results

The mean percentage time ± SD that intragastric pH was ≥3 was 68.4 ± 35.0% for fOT, 73.9 ± 23.2% for ORP, 42.8 ± 18.6% for famotidine, and 16.0 ± 14.2% for placebo. Mean ± SD plasma omeprazole concentrations were similar in cats receiving fOT compared to those receiving ORP and in a range associated with acid suppression reported in other studies.

Conclusions and Clinical Importance

These results suggest that both omeprazole formulations provide superior acid suppression in cats compared to famotidine or placebo. Fractionated enteric‐coated OT is an effective acid suppressant despite disruption of the enteric coating.

Serum concentrations of gastrin after famotidine and omeprazole administration to dogs

Background

The duration of antacid‐induced hypergastrinemia after cessation of administration of omeprazole and famotidine apparently has not been determined in dogs.

Hypothesis

That serum gastrin will return to basal concentrations by 7 days after cessation of famotidine or omeprazole administration.

Animals

Nine healthy, adult, male, research colony dogs.

Methods

Randomized, cross‐over design. Serum gastrin was determined daily for 7 days to establish baseline concentrations. Famotidine (1.0 mg/kg q24h) or omeprazole (1.0 mg/kg q24h) was administered PO for 7 days followed by a 14‐day washout. Serum concentrations of gastrin were determined daily during 7 days of administration and daily for 7 days after cessation of administration. Each drug was evaluated in 8 of the 9 dogs.

Results

Omeprazole caused a significant increase in serum gastrin concentration (37.2 ± 7.3 to 71.3 ± 19.0 ng/L; P = .006). Famotidine induced a transient increase in serum gastrin (37.2 ± 7.3 to 65.5 ± 38.5 ng/L; P = .02) that peaked at administration day 3 and declined thereafter. By day 7 after cessation of both drugs, there was no difference in serum gastrin concentrations compared to those before administration (famotidine P = .99; omeprazole P = .99). During or after administration, gastrin concentrations above 3 times the upper reference range were rare (12 of 224 samples).

Conclusions and Clinical Importance

A 7‐day withdrawal from short‐term administration of famotidine or omeprazole is sufficient for serum gastrin to return to baseline concentrations. Withholding famotidine or omeprazole for longer before investigating pathologic causes of hypergastrinemia is unnecessary.

Effect of simulated deployment patrols on gastric mucosa of explosive detection dogs

Exercise-induced gastric disease is well-recognised in dogs performing ultra-endurance racing, but has not been described in dogs performing non-competitive athletic activities. Explosive detection dogs often perform prolonged periods of exercise and are reported to have chronic inappetance and weight-loss consistent with gastric disease. Seven privately-owned Labrador Retrievers trained for off-leash explosive detection activities were used to test the hypothesis that explosive detection dogs develop exercise-induced gastric disease while performing routine duties. Gastroscopy was performed on dogs before and after a 5-day exercise challenge designed to simulate routine military deployment activities. Five days of sustained submaximal exercise resulted in substantial gastric disease. These results demonstrate that dogs performing prolonged submaximal exercise consistent with off-leash explosive detection patrols are susceptible to exercise-induced gastric disease. Exercise-induced gastric disease may explain the anecdotal reports of poor thrift in these types of dogs during military deployment, and prophylactic acid suppression therapy should be considered in dogs participating in these activities.

A review of stress-related mucosal disease

OBJECTIVE

To review and summarize the human and veterinary literature regarding stress-related mucosal disease (SRMD) pathogenesis, patient risk factors, and therapeutic options for prophylaxis and treatment.

ETIOLOGY

SRMD is a common sequela of critical illness in human patients. Development of SRMD results from splanchnic hypoperfusion, reperfusion injury, and exposure of the gastric mucosa to acid, pepsin, and bile acids following breakdown of the gastric mucosal defense system. Human patients with the highest risk of stress ulceration include those with respiratory failure necessitating mechanical ventilation greater than 48 h or coagulopathy. Currently, little is known about the incidence and pathophysiology of SRMD in critically ill veterinary patients.

DIAGNOSIS

A presumptive diagnosis can be made in high-risk patient populations following detection of occult or gross blood in nasogastric tube aspirates, hematemesis, or melena. Definitive diagnosis is achieved via esophagogastroduodenoscopy. Lesions are localized to the acid-producing portions of the stomach, the fundus, and body.

THERAPY

Therapy is aimed at optimization of tissue perfusion and oxygenation. Pharmacologic interventions are instituted to increase intraluminal pH and augment natural gastric defenses. Histamine(2)-receptor antagonists, proton pump inhibitors, and sucralfate are the mainstays of therapy. In people, clinically significant bleeding may necessitate additional interventions (eg, packed red blood cell transfusions, endoscopic, or surgical hemostasis).

PROGNOSIS

Mortality is increased in people with clinically significant bleeding compared to those patients who do not bleed. Institution of prophylaxis is recommended in high-risk patients. However, no consensus exists regarding initiation of prophylaxis, preference of frontline drug class, or indication for discontinuation of therapy. The prognosis of veterinary patients with SRMD remains unknown at this time.

Clinical pharmacology of nonsteroidal anti-inflammatory drugs in dogs

OBJECTIVES

To discuss the clinical pharmacology of currently licensed veterinary NSAIDs and to review gastrointestinal and renal adverse effects as well as drug-drug interactions that have been reported with these drugs. To review the use of NSAIDs in the peri-operative setting and their use in patients with osteoarthritis. To further review the reported effects of NSAIDs on canine articular cartilage and liver as well as the clinical relevance of a washout period.

DATABASES USED

PubMed, CAB abstracts and Google Scholar using dog, dogs, nonsteroidal anti-inflammatory drugs and NSAID(s) as keywords.

CONCLUSIONS

A good understanding of the mechanisms by which NSAIDs elicit their analgesic effect is essential in order to minimize adverse effects and drug-drug interactions. Cyclooxygenase (COX) is present in at least two active isoforms in the body and is the primary pharmacologic target of NSAIDs. Inhibition of COX is associated with the analgesic effects of NSAIDs. COX is present in the gastrointestinal tract and kidneys, along with other areas of the body, and is also the likely reason for many adverse effects including gastrointestinal and renal adverse effects. The newer veterinary approved NSAIDs have a lower frequency of gastrointestinal adverse effects in dogs compared to drugs such as aspirin, ketoprofen and flunixin, which may be due to differential effects on the COX isoforms. There are currently no published reports demonstrating that the newer NSAIDs are associated with fewer renal or hepatic adverse effects in dogs. NSAIDs remain the cornerstone of oral therapy for osteoarthritis unless contraindicated by intolerance, concurrent therapies or underlying medical conditions. NSAIDs are also effective and frequently used for the management of post-operative pain.

Efficacy of oral famotidine and 2 omeprazole formulations for the control of intragastric pH in dogs

BACKGROUND

Little is known about the efficacy of commonly used acid suppressants on intragastric pH in dogs.

OBJECTIVE

To compare the effect of oral famotidine, 2 formulations of omeprazole, and placebo on intragastric pH in dogs with a catheter-free, continuous pH monitoring system.

ANIMALS

Six healthy adult mixed-breed colony dogs.

METHODS

Utilizing a randomized, 4-way cross over, open-label study, dogs were administered famotidine PO (1.0-1.3 mg/kg q12h), omeprazole tablet (1.5-2.6 mg/kg q24h), omeprazole reformulated paste (RP) (Gastrogard, 1.5-2.6 mg/kg q24h), and placebo for 7 days followed by a 10-day washout period. Radiotelemetric pH capsules were placed with gastroscopy assistance to continuously record intragastric pH for 4 days (days 4-7 of dosing). The percentage of time that intragastric pH was ≥3 and ≥4 was compared among treatment groups using repeated measures of analysis of variance. Tukey's Studentized range test was used to determine which groups were different with α= 0.05.

RESULTS

Mean ± SD percent time intragastric pH was ≥3 and ≥4 was 22 ± 8% and 14 ± 6% for famotidine, 63 ± 14% and 52 ± 17% for omeprazole tablet, 54 ± 17% and 44 ± 18% for omeprazole RP, and 6 ± 6% and 5 ± 5% for placebo. Both omeprazole formulations significantly increased intragastric pH compared with famotidine and placebo, but omeprazole tablet and RP was not significantly different from each other.

CONCLUSION

Oral omeprazole tablet and RP provide superior gastric acid suppression to famotidine, and should therefore be considered more effective for the treatment of acid related disorders in dogs.