Management of acute-onset pancreatitis in dogs: a Narrative Review.

Acute-onset pancreatitis (AP) is common in dogs and presents diagnostic as well as management challenges. Until recently, the management of AP in dogs was based mainly on supportive and symptomatic care. Identification and management of a possible cause of the disease is important, but the majority of cases are considered to be idiopathic. Fluid therapy that is tailored to the patient's needs is crucial to provide adequate hydration while preventing overhydration. Antiemetics are required to control vomiting and fluid loss and aid in early nutritional support. Recognition and management of complications is also crucial. Furthermore, analgesics for abdominal pain are very important. More recently, pharmaceutical modification of the inflammatory cascade has gained interest and the first specific therapeutic agent for the treatment of AP, fuzapladib sodium, has been shown to have a reasonable expectation of effectiveness in a pilot study. This drug has been licensed for the treatment of clinical signs of AP in dogs in Japan and also has achieved FDA conditional approval in the US. Antibiotics should not be used indiscriminately but are indicated for patients with aspiration pneumonia, gastrointestinal bacterial translocation, or evidence of another bacterial infection. Proton pump inhibitors and plasma are not routinely prescribed in pancreatitis unless specifically indicated. Nonsteroidal anti-inflammatory drugs should be avoided. Corticosteroid therapy, once thought to be contraindicated, may have some beneficial effects, as shown in a single retrospective study. However, further studies are required before their routine use can be recommended. Finally, a surgical approach is rarely indicated.

Demographic and histopathologic features of dogs with abnormally high concentrations of hepatic copper.

BACKGROUND: Copper associated hepatopathy (CAH) has become an important and prevalent disease since the 1990's, coincidental with changes in copper (Cu) content in commercial dog foods. Knowing the demographic and histopathologic features related to hepatic Cu concentrations might aid in diagnosing CAH in dogs. HYPOTHESIS/OBJECTIVES: The primary aim was to identify demographic and histopathologic features associated with abnormally high hepatic Cu concentrations. ANIMALS: Dogs that underwent liver histopathology and Cu quantification at a veterinary diagnostic laboratory between July 2010 and February 2020. METHODS: Data was retrospectively collected from an electronic database. A Gaussian multiple regression model on the log scale was used to evaluate associations between hepatic Cu and a set of demographic and histologic features selected with machine learning methods. RESULTS: Of 4559 cases meeting criteria, 50% had hepatic Cu > 400 and 19% had Cu > 1000 ppm (parts per million) dry weight (reference range 120-400). Median hepatic Cu was 391 ppm, range 4.5 to 31500. Age was negatively associated (P < .02), but specific breeds (Doberman pinscher, Labrador retriever, and West Highland white terrier) were positively associated with abnormally high hepatic Cu (P < .001). Severity of inflammation (mild, moderate, and severe) and necrosis/apoptosis were associated with abnormally high hepatic Cu (P < .01). CONCLUSION AND CLINICAL IMPORTANCE: Abnormally high hepatic Cu is prevalent in hepatic biopsies from dogs. Machine learning modeling showed that necroinflammation, not cholestasis or cirrhosis, on hepatic histopathology, is predictive of higher hepatic Cu and might be a reliable histologic predictor of CAH.

Strongly acidic gastroesophageal reflux and esophageal lumen pH before and after esophageal lavage with water or two bicarbonate concentrations in anesthetized dogs.

OBJECTIVE: To increase acidic esophageal lumen pH in dogs that developed gastroesophageal reflux (GER) during anesthesia. We compared water and 2 different bicarbonate concentrations. ANIMALS: 112 healthy, nonbrachycephalic dogs presented for ovariectomy. PROCEDURES: Following standard anesthesia and surgery protocols for ovariectomy in all dogs, esophageal lumen impedance and pH were monitored using a dedicated probe. Esophageal impedance indicates the presence of GER whereas pH indicates the acidity level. Dogs with strongly acidic GER and an esophageal lumen pH value < 4.0 were included in the study, and lavage was performed with either tap water, bicarbonate 1%, or bicarbonate 2% until the pH increased to > 4.0. The effect of lavage on esophageal pH was compared using the Kruskal-Wallis and Wilcoxon 2 sample tests. Associations between lavage and pH changes were determined. RESULTS: Of 48/112 dogs with strongly acidic GER, 33% neutralized their esophageal pH during surgery. For the 32 dogs that maintained an esophageal lumen pH value < 4, esophageal lavage with water increased the lumen pH to > 4 in 78.6% of dogs, whereas both bicarbonate concentrations increased it in 100% of the dogs to a more neutral pH (P < .0001). The dogs in the water group were more likely to regurgitate after anesthesia (36% vs 0% in both bicarbonate groups, P = .028). CLINICAL RELEVANCE: Bicarbonate 1% and 2% increased esophageal lumen pH to more than 4 after strongly acidic GER. Lavage with water was mildly effective, but required large volumes and predisposed to further regurgitation after anesthesia.

Assessment of the intracellular distribution of copper in liver specimens from cats.

The intracellular distribution of copper in the liver has been investigated in dogs and humans. However, this has not been reported in cats. This study aimed to assess the intracellular copper distribution in liver specimens from cats with a range of hepatic copper concentrations. Twenty-nine frozen liver specimens from cats were included. Each liver specimen was divided into two pieces for overall copper quantification and tissue fractionation. The copper concentrations in liver specimens and liver fractions were measured by flame atomic absorption spectroscopy. Five specimens had copper concentrations < 100 µg/g dry weight, eight had copper concentrations between 100 and 180 µg/g, 14 had copper concentrations between 181 and 700 µg/g, and two had copper concentrations >700 µg/g. Only one specimen had positive copper staining. Regardless of the overall concentrations, copper was mostly found in the cytosolic fraction followed by the nuclear, large granule, and microsomal fractions. Our findings indicate that similarly to other species, intracellular copper is predominantly found in the cytosolic and nuclear fractions in cats. The distribution in cats with copper-loaded conditions, such as primary copper hepatopathy, was not assessed but warrants evaluation.

Advances in the diagnosis of acute pancreatitis in dogs.

In the last 20 years, the diagnosis of pancreatitis has become more frequent as a result of improved diagnostic modalities such as abdominal ultrasound examination, advanced imaging, and immunoassays for the measurement of pancreatic lipase. Our aim is to provide a state-of-the-art overview of the clinical diagnosis of acute pancreatitis (AP) in dogs with a particular focus on pancreatic lipase assay validation and clinical performance, in addition to advanced imaging modalities. We also discuss the potential indications for cytology and histopathology in dogs with suspected AP.

Assessment of copper accumulation in archived liver specimens from cats.

OBJECTIVES: The aim of this study was to assess hepatic copper concentrations and zonal distribution in cat liver specimens. METHODS: For this study, 121 archived, formalin-fixed, paraffin-embedded liver specimens from cats were used. Tissue sections were stained for copper with rhodanine and scored from 0 (no copper accumulation) to 5 (panlobular copper accumulation). The tissue specimens were then deparaffinized and hepatic copper concentrations were measured using flame atomic absorption spectroscopy. RESULTS: Tissue samples were categorized into four groups based on histopathologic findings: (1) no significant histopathologic hepatic changes (n = 66); (2) hepatic steatosis (n = 18); (3) inflammatory or infectious disease (n = 24); and (4) neoplasia (n = 13). Of the 121 specimens, 13 (11%) stained positive for copper, with three having a score ⩾3. Thirty-seven specimens (31%) had copper concentrations above the reference interval ([RI] <180 µg/g dry weight liver). Copper concentrations in cats with hepatic inflammatory or infectious disease were significantly higher than cats with hepatic steatosis (P = 0.03). Copper-staining score and concentration were positively correlated (rs = 0.46, P <0.001). CONCLUSIONS AND RELEVANCE: Despite the fact that 31% of specimens had copper concentrations above the RI, only 11% showed positive copper staining and only 2.5% had a score ⩾3. Our findings suggest that hepatic copper concentrations greater than the upper limit of the RI are relatively common in cats. Further studies to determine the factors that influence hepatic copper staining in cats and to establish contemporary RIs for hepatic copper in healthy cats are warranted.

Computed tomographic evaluation of pancreatic perfusion in healthy dogs.

OBJECTIVE: To evaluate the feasibility of contrast-enhanced CT for assessment of pancreatic perfusion in healthy dogs. ANIMALS: 6 healthy purpose-bred female Treeing Walker Coonhounds. PROCEDURES: Contrast-enhanced CT of the cranial part of the abdomen was performed with 3-mm slice thickness. Postprocessing computer software designed for evaluation of human patients was used to calculate perfusion data for the pancreas and liver by use of 3-mm and reformatted 6-mm slices. Differences in perfusion variables between the pancreas and liver and differences in liver-specific data of interest were evaluated with the Friedman test. RESULTS: Multiple pancreatic perfusion variables were determined, including perfusion, peak enhancement index, time to peak enhancement, and blood volume. The same variables as well as arterial, portal, and total perfusion and hepatic perfusion index were determined for the liver. Values for 6-mm slices appeared similar to those for 3-mm slices. The liver had significantly greater median perfusion and peak enhancement index, compared with the pancreas. CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of pancreatic perfusion with contrast-enhanced CT was feasible in this group of dogs. Hepatic arterial and pancreatic perfusion values were similar to previously published findings for dogs, but hepatic portal and hepatic total perfusion measurements were not. These discrepancies might have been attributable to physiologic differences between dogs and people and related limitations of the CT software intended for evaluation of human patients. Further research is warranted to assess reliability of perfusion variables and applicability of the method for assessment of canine patients with pancreatic abnormalities.

Serum D-lactate concentrations in dogs with parvoviral enteritis.

BACKGROUND: Dogs infected with canine parvovirus (CPV) have compromised intestinal epithelial barrier integrity. Production of D-lactate by enteric bacteria may directly reflect disease severity or contribute to metabolic acid-base status in these dogs. HYPOTHESIS: Serum D-lactate concentration will be increased in CPV dogs compared to healthy controls and correlate with markers of disease severity and acid-base status. ANIMALS: Dogs with CPV undergoing treatment (n = 40) and healthy control dogs (n = 9). METHODS: Prospective observational study. Dogs with CPV had a baseline and daily CBC, venous blood gas with serum electrolyte concentrations, composite clinical severity score, and serum D-lactate concentration performed. A single serum D-lactate measurement was obtained from healthy control dogs. RESULTS: The CPV dogs had a higher D-lactate concentration (mean ± SD) of 469 ± 173 µM compared to controls, 306 ± 45 µM (P < .001). There was no difference in baseline D-lactate concentrations for CPV survivors (474 ± 28 µM), versus nonsurvivors (424 ± 116 µM; P = .70). D-lactate concentration decreased over the first 4 days of treatment (-9.6 µM/d; P = .46). Dogs hospitalized for <4 days had lower baseline D-lactate concentrations compared to those hospitalized ≥4 days (400 ± 178 µM versus 520 ± 152 µM; P = .03). No sustained correlation over time between serum D-lactate concentration and clinical severity score or recorded acid-base results. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum D-lactate concentrations are higher in dogs with CPV compared to healthy controls but do not appear to be clinically relevant. No relationship identified between serum D-lactate concentrations and markers of CPV disease severity, acid-base status, or outcome.

CT angiographic changes in dogs with acute pancreatitis: A prospective longitudinal study.

Computed tomographic angiography (CTA) has recently been shown to be a useful tool in the diagnosis of acute canine pancreatitis, the identification of pancreatic necrosis, and the detection of sequelae. Evidence of pancreatic necrosis on CTA has been shown to be correlated with a poorer outcome in both humans and dogs and early diagnosis and intervention may improve outcomes. In humans, pancreatic necrosis is typically evident on CTA within 48 h of clinical signs, thus, repeat CTA examinations are often performed to identify pancreatic necrosis that may not have been evident on CTA examinations performed early in the course of disease. Published information investigating the timing of CTA examinations and the use of serial CTA in dogs with acute pancreatitis is lacking. In this prospective, longitudinal study, CTA examinations were performed at the time of hospitalization and repeated 3-5 days later in 11 dogs suffering from acute canine pancreatitis to determine if pancreatic necrosis or sequelae are under diagnosed on examinations performed at the time of hospitalization. Computed tomographic angiography studies were evaluated for changes in pancreatic size, pancreatic contrast enhancement, and peri-pancreatic tissues and vessels. The only statistically significant difference between the initial and repeat CTA examinations was the improvement of fat stranding on the repeat CTA examinations (P < .045). Based on these results, CTA performed at the time of admission is likely adequate in the diagnosis and evaluation of dogs with acute pancreatitis. Repeat CTA examinations are unlikely to add additional information in the absence of worsening clinical signs.

Retrospective evaluation of cyclosporine in the treatment of presumed idiopathic chronic hepatitis in dogs.

BACKGROUND: The etiology of idiopathic chronic hepatitis (ICH) in dogs is poorly understood, but evidence supports an immune-mediated pathogenesis in some dogs. OBJECTIVES: To describe a case series of dogs with presumed ICH treated with cyclosporine (CsA) with or without concurrent medications and to document the incidence of biochemical remission and factors associated with failure to attain remission. ANIMALS: Forty-eight client-owned dogs diagnosed with presumed ICH, treatment of which included CsA. METHODS: Two-institution, retrospective case series of dogs between 2010 and 2017. All dogs were treated with CsA with or without concurrent medications for ≥2 weeks. Data were collected from medical records. RESULTS: Biochemical remission (<1.1 times the upper limit of normal for alanine aminotransferase activity) was attained in 79% of dogs (38/48). Median dose of CsA at remission was 7.9 mg/kg/d (range, 2.5-12.7 mg/kg/d) and median time to remission was 2.5 months (range, 0.75-18 months). Concurrent hepatoprotectant treatment was not associated with likelihood of remission. Clinical score, ascites, hypoalbuminemia, hyperbilirubinemia, prolonged coagulation times, dose, and duration of treatment were not associated with the probability of remission or time to remission. Common adverse effects of CsA were gastrointestinal signs in 38% (18/48) and gingival hyperplasia in 25% (12/48) of treated dogs. CONCLUSION AND CLINICAL IMPORTANCE: A treatment regimen including CsA and frequent hepatoprotectant use resulted in biochemical remission of ICH in most dogs. None of the evaluated factors, including hepatoprotectant use, were significantly associated with likelihood of remission. Future prospective studies are indicated to evaluate CsA monotherapy in ICH dogs.

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs.

This consensus statement on chronic hepatitis (CH) in dogs is based on the expert opinion of 7 specialists with extensive experience in diagnosing, treating, and conducting clinical research in hepatology in dogs. It was generated from expert opinion and information gathered from searching of PubMed for manuscripts on CH, the Veterinary Information Network for abstracts and conference proceeding from annual meetings of the American College of Veterinary Medicine and the European College of Veterinary Medicine, and selected manuscripts from the human literature on CH. The panel recognizes that the diagnosis and treatment of CH in the dog is a complex process that requires integration of clinical presentation with clinical pathology, diagnostic imaging, and hepatic biopsy. Essential to this process is an index of suspicion for CH, knowledge of how to best collect tissue samples, access to a pathologist with experience in assessing hepatic histopathology, knowledge of reasonable medical interventions, and a strategy for monitoring treatment response and complications.

Computed tomographic angiography and ultrasonography in the diagnosis and evaluation of acute pancreatitis in dogs.

BACKGROUND: Acute pancreatitis in dogs is an under-diagnosed disease. Current diagnostic methods are insufficient at identifying sequelae and lack prognostic capability. Computed tomographic angiography (CTA) is accurate for diagnosis and prognostication of pancreatitis in humans. OBJECTIVES: In comparison to ultrasound (US), CTA will (1) better diagnose more severe pancreatitis and sequelae and (2) provide assessment of patient outcome by identification of pancreatic contrast enhancement patterns. ANIMALS: Twenty-six client-owned dogs suspected to have acute pancreatitis. METHODS: US and CTA examinations performed at time of admission were compared to determine the detection of pancreatic changes and sequelae. CTA findings also were compared to outcome indicators for prognosis of dogs with acute pancreatitis. Specific canine pancreatic lipase (cPL) samples were obtained and compared with CTA findings. RESULTS: Ten of 26 dogs had heterogeneous contrast enhancement of the pancreas. Compared to US, CTA better identified portal vein thrombosis (P = .003). Patients with heterogeneous contrast enhancement had longer hospitalization (P = .01), including hospital stays for >5 days (P = .02), had more relapses, and were more likely to have portal vein thrombosis (P = .002). Patients with heterogeneous contrast enhancement had increased spec cPL (P = .006). CONCLUSIONS AND CLINICAL IMPORTANCE: In comparison to US, CTA better identified dogs with more severe acute pancreatitis and those with portal vein thrombosis, factors that may predict longer hospitalization and increased risk of relapse. The presence of heterogeneous contrast enhancement and portal vein thrombosis may change therapy for patients with acute pancreatitis.

Assessing the Efficacy of Maropitant Versus Ondansetron in the Treatment of Dogs with Parvoviral Enteritis.

Antiemetics are commonly prescribed during the treatment of canine parvoviral enteritis. This blinded, randomized prospective study compared the quality of clinical recovery and duration of hospitalization in canine parvoviral dogs receiving either maropitant (1 mg/kg [0.45 mg/lb] IV q 24 hr, n = 11) or ondansetron (0.5 mg/kg [0.23 mg/lb] IV q 8 hr, n = 11). All dogs were treated with IV fluids, cefoxitin, and enteral nutrition. Frequency of vomiting and pain scoring were recorded twice daily. Rescue analgesics and antiemetics were administered as dictated by specific pain and vomiting criteria. Clinical severity scoring, body weight, and caloric intake were monitored daily. When comparing dogs receiving maropitant versus ondansetron, respectively, there were no differences in duration of hospitalization (3.36 ± 0.56 versus 2.73 ± 0.38 days, P = .36), requirement of rescue antiemetic (3/11 versus 5/11 dogs, P = .66), duration of vomiting (5 versus 4 days, P = .65), or days to voluntary food intake (2 versus 1.5 days, P = 1.0). Results of this study suggest that maropitant and ondansetron are equally effective in controlling clinical signs associated with parvoviral enteritis.

Effect of hospitalization on gastrointestinal motility and pH in dogs.

OBJECTIVE To determine the effect of hospitalization on gastrointestinal motility and pH in healthy dogs. DESIGN Experimental study. ANIMALS 12 healthy adult dogs. PROCEDURES A wireless motility capsule (WMC) that measured pressure, transit time, and pH within the gastrointestinal tract was administered orally to dogs in 2 phases. In the first phase, dogs received the WMC at the hospital and then returned to their home to follow their daily routine. In the second phase, dogs were hospitalized, housed individually, had abdominal radiography performed daily, and were leash exercised 4 to 6 times/d until the WMC passed in the feces. All dogs received the same diet twice per day in both phases. Data were compared between phases with the Wilcoxon signed rank test. RESULTS Data were collected from 11 dogs; 1 dog was excluded because the WMC failed to exit the stomach. Median gastric emptying time during hospitalization (71.8 hours; range, 10.7 to 163.0 hours) was significantly longer than at home (17.6 hours; range, 9.7 to 80.8 hours). Values of all other gastric, small bowel, and large bowel parameters (motility index, motility pattern, pH, and transit time) were similar between phases. No change in gastric pH was detected over the hospitalization period. High interdog variability was evident for all measured parameters. CONCLUSIONS AND CLINICAL RELEVANCE Hospitalization of dogs may result in a prolonged gastric emptying time, which could adversely affect gastric emptying of meals, transit of orally administered drugs, or assessments of underlying motility disorders.

Evaluation of an outpatient protocol in the treatment of canine parvoviral enteritis.

OBJECTIVE: To compare 2 treatment protocols (standard in-hospital versus modified outpatient) in affecting the duration of treatment or survival of dogs with parvoviral enteritis. DESIGN: Prospective, randomized study. SETTING: University teaching hospital. ANIMALS: Client-owned dogs with naturally acquired parvovirus were randomized to receive either an inpatient (n = 20) or outpatient (n = 20) treatment protocol. INTERVENTIONS: Both groups received intravenous (IV) fluid resuscitation and correction of hypoglycemia at hospital admission. Following stabilization, basic inpatient interventions included administration of IV fluids, administration of cefoxitin (22 mg/kg IV q 8 h), and maropitant (1 mg/kg IV q 24 h). Basic outpatient interventions (provided in-hospital) included administration of subcutaneous (SC) fluid (30 mL/kg q 6 h), administration of maropitant (1 mg/kg SC q 24 h) and cefovecin (8 mg/kg SC once). Using daily electrolyte and glucose evaluations, dextrose and potassium supplementation was provided intravenously (inpatients) or orally (outpatients) as indicated. Rescue criteria were used in both groups for analgesia and nausea. All dogs were syringe fed a commercial canine convalescence diet (1 mL/kg PO q 6 h) until voluntary appetite returned. MEASUREMENTS AND MAIN RESULTS: Protocol success, defined as survival to hospital discharge, was 90% (18/20) for the inpatient group compared to 80% (16/20) for the outpatient group (P = 0.66). There was no difference detected in duration of hospitalization for inpatient dogs (4.6 ± 2 days) versus outpatient dogs (3.8 ± 1.8 days, P = 0.20). Metabolic disturbances were frequent in the outpatient group, with 50% of dogs requiring dextrose supplementation and 60% of dogs requiring potassium supplementation. CONCLUSIONS: An outpatient protocol may be a reasonable alternative for dogs that cannot receive standard in-hospital treatment for parvoviral enteritis. Diligent supportive care and monitoring are still required to optimize treatment of dogs with parvoviral enteritis in an outpatient setting.

Palatability and Clinical Effects of an Oral Recuperation Fluid During the Recovery of Dogs With Suspected Parvoviral Enteritis.

Dogs infected with canine parvovirus (CPV) can develop severe enteritis that requires supportive care until voluntary food and water consumption return. An oral recuperation fluid (ORF) may assist in the overall recovery from CPV. The hypotheses of the study were that dogs with naturally infected CPV would prefer the ORF to water and that dogs consuming the ORF would have a more rapid return to voluntary appetite and improved caloric intake during the initial recovery period compared with dogs consuming water. A total of 28 dogs with CPV were enrolled. Dogs were excluded if voluntary food or water intake was present at the time of study enrollment. Dogs were randomized to either an ORF or water group. The designated fluid was offered twice daily, followed by offering the opposite fluid 1 hour later if the designated fluid was refused. Dogs also received a standardized supportive treatment protocol. Beginning on day 2, all dogs were offered a gastrointestinal diet q8h, staggered with the fluid intake trials. A total of 40% (6/15) of dogs with CPV consumed the ORF as their designated fluid, and 31% (4/13) of dogs with CPV consumed water as their designated fluid (P = .71). For those dogs who refused their designated fluid, 56% (5/9) of the dogs consuming ORF ultimately consumed water, and 22% (2/9) of the dogs consuming water also consumed the ORF (P = .33). Dogs who consumed the ORF demonstrated a more rapid return to voluntary appetite (median = 1.5 days [range: 1-3]) compared with those that consumed water (median = 4.25 days [range: 1.5-5.5], P = .01) or neither fluid (median = 2 days [range: 1.5-5.5], P = .03). Additionally, those dogs consuming the ORF demonstrated greater caloric intake [median = 100% resting energy requirement (RER), range: 61%-100%] compared with those that consumed water (median = 19% RER; range: 9%-100%; P = .004) or neither fluid (median = 37% RER; range: 3-100; P = .05). This study suggests that some dogs with CPV voluntarily consume an ORF during the recovery phase of their illness and that consumption of the ORF may foster a more rapid return of voluntary appetite as well as improved caloric intake. Additional studies are warranted to further assess additional effects of this ORF during recovery from CPV.

Prospective Controlled Study of Gastroesophageal Reflux in Dogs with Naturally Occurring Laryngeal Paralysis.

OBJECTIVE: To determine the frequency, nature, and magnitude of gastroesophageal reflux (GER) in dogs with laryngeal paralysis (LP). STUDY DESIGN: Prospective comparative clinical study. ANIMALS: Client-owned dogs with LP and healthy client-owned dogs (n = 6 each). METHODS: Dogs underwent sedated laryngeal examination for diagnosis and grading of bilateral LP and for placement of a nasoesophageal dual pH/impedance probe. Endoscopy was used to confirm probe location and evaluate the distal esophagus. Data were recorded continuously. GER was defined as pH<4 or >7.5 lasting >2 seconds reaching a magnitude of 2 impedance sensors proximally. RESULTS: The median total number of GER events per hour was 0.64 (range, 0.44-1.6) for the LP group and 0.53 (range, 0.38-1.0) for the control group (P = 0.259; power = 0.50). The median total number of alkaline regurgitation events per hour was 0.37 (range, 0.17-0.93) for the LP group and 0.46 (range, 0.25-1.0) for control group (P = 0.575; power = 0.57). The median total number of acidic regurgitation events per hour was 0.22 (range, 0-0.70) and 0.0 (range, 0-0.14) for the LP and control groups, respectively (P = 0.025). Acidic reflux events reached the proximal pH sensor in 2 dogs in the LP group for a total of 4 reflux events and in 1 dog in the control group for a total of 3 reflux events (P = 0.673). CONCLUSION: Based on the limited number of dogs studied, it appears that dogs with naturally occurring LP have increased acidic reflux events compared to clinically normal dogs. GER can reach the most proximal part of the esophagus.