Identification of Genetic Susceptibility Factors Associated with Canine Gastric Dilatation-Volvulus.

Canine gastric dilatation-volvulus (GDV) is a common life-threatening condition occurring primarily in large and giant breeds with a 3.9% to 36.7% lifetime risk. The genetic correlates of GDV have not previously been systematically explored. We undertook an inter-breed genome-wide association analysis (GWAS) of 253 dogs from ten breeds including 106 healthy dogs and 147 dogs with at least one GDV episode. SNP array genotyping followed by imputation was conducted on 241 samples to identify GDV-associated single-nucleotide polymorphisms (SNPs) and copy number variations (CNVs). A subset of 33 dogs (15 healthy dogs and 18 GDV patients from the three most represented breeds) was characterized by whole genome sequencing (WGS). After genome-wide Bonferroni correction, we identified a significant putatively protective intergenic SNP (rs851737064) across all breeds. The signal was most significant in Collies, German Shorthaired Pointers, and Great Danes. Subsequent focused analysis across these three breeds identified 12 significant additional putatively protective or deleterious SNPs. Notable significant SNPs included those occurring in genes involved in gastric tone and motility including VHL, NALCN, and PRKCZ. These data provide important new clues to canine GDV risk factors and facilitate generation of hypotheses regarding the genetic and molecular underpinnings this syndrome.

Peritoneal fluid analysis in dairy cows with left displaced abomasum and abomasal volvulus.

Peritoneal fluid (PF) was evaluated in 40 cows with left displaced abomasum (LDA) and 15 cows with abomasal volvulus (AV). PF was obtained by abdominocentesis at the right ventral abdomen at admission. Simultaneously, a blood sample was taken from the jugular vein. Biochemical and cytological variables in blood and PF specific for ischaemia, inflammation and cell damage were compared. Total protein, albumin, glucose and cholesterol were normal in PF of cows with LDA and AV. Although L-lactate increased in both groups, cows with AV had significantly higher values (LDA: 1.47/0.69/2.68 mmol/l; AV: 6.45/4.55/12.89 mmol/l (median/1. quartile/3. quartile)). D-dimer (LDA: 0.50/0.22/0.88 mg/l; AV: 1.11/0.40/1.85 mg/l) and LDH (LDA: 663/437/943 U/l; AV: 1099/750/1439 U/l) were only increased in PF of cows with AV. The number of leucocytes was normal; however, significantly more peritoneal neutrophils appeared necrotic or apoptotic after AV. PF of cows with abomasal displacement showed distinctive features of ischaemia and inflammation. Characteristics of haemostatic dysfunction and cell damage were mainly evident in PF of cows with AV. The results suggest that anti-inflammatory therapy is indicated in each cow with abomasal displacement. Additionally, medical treatment should be directed to prevent complications of ischaemia and reperfusion in cows with AV.

Diaphragmatic hernia presenting as gastrointestinal bleeding.

We report a 5-year-old girl who presented with persistent iron-deficiency anemia. She had a history of abdominal pain and recurrent gastrointestinal bleeding. High-resolution computed tomography, esophagogastroduodenoscopy and barium meal examination revealed a congenital diaphragmatic hernia with intermittent gastric volvulus. The anemia was the result of Cameron lesions associated with diaphragmatic hernia.

The effect of experimental gastric dilatation-volvulus on adenosine triphosphate content and conductance of the canine gastric and jejunal mucosa.

The objective of this study was to determine if experimental gastric dilatation volvulus (GDV) would decrease adenosine triphosphate (ATP) concentration and increase membrane conductance of the canine gastric and jejunal mucosa. Male dogs (n = 15) weighing between 20 and 30 kg were used. Dogs were randomly assigned to 1 of 3 equal groups: Group 1 was control, group 2 was GDV, and group 3 was ischemia. All dogs were anesthetized for 210 min. Group 1 had no manipulation. Group 2 had GDV experimentally induced for 120 min followed by decompression, derotation, and reperfusion for 90 min. Group 3 had GDV experimentally induced for 210 min. Gastric (fundus and pylorus) and jejunal tissue was taken at 0, 120, and 210 min from all of the dogs. Tissue was analyzed for ATP concentration, mucosal conductance, and microscopic changes. The ATP concentration in the fundus did not change significantly from baseline in group 2, but decreased significantly below baseline at 210 min in group 3. The ATP concentration in the jejunum decreased significantly below baseline in groups 2 and 3 at 120 min, remaining significantly decreased in group 3 but returning to baseline at 210 min in group 2. Mucosal conductance of the fundus did not change significantly in any dog. Mucosal conductance of the jejunum increased at 120 min in groups 2 and 3, and became significantly increased above baseline at 210 min. The jejunal mucosa showed more profound cellular changes than the gastric mucosa. The jejunum showed substantial decreases in ATP concentration with an increase in mucosal conductance, suggesting cell membrane dysfunction. Dogs sustaining a GDV are likely to have a change in the activity of mucosal cells in the jejunum, which may be important in the pathophysiology of GDV.

Calculation of variables describing plasma nonvolatile weak acids for use in the strong ion approach to acid-base balance in cattle.

OBJECTIVE: To calculate values for the total concentration of nonvolatile weak acids (Atot) and the effective dissociation constant for nonvolatile weak acids (Ka) of bovine plasma and to determine the best method for quantifying the unmeasured strong anion concentration in bovine plasma. SAMPLE POPULATION: Data sets from published and experimental studies. PROCEDURE: The simplified strong ion model was applied to published and experimentally determined values for pH, PCO2, and strong ion difference (SID+). Nonlinear regression was used to solve simultaneously for Atot and Ka. Four methods for quantifying the unmeasured strong anion concentration in plasma (anion gap, the Fencl base excess method [BEua], the Figge unmeasured anion method [XA], and the strong ion gap [SIG]) were compared in 35 cattle with abomasal volvulus. RESULTS: For bovine plasma at 37 C, Atot was 25 m M/L, equivalent to 76 times the albumin concentration or 3.6 times the total protein concentration; Ka was 0.87 x 10(-7), equivalent to pKa of 706. The Atot and Ka values were validated, using data sets from in vivo and in vitro studies. Plasma unmeasured strong anion concentration was most accurately predicted in critically ill cattle by calculating SIG from serum albumin (R2, 0.66) or total protein concentration (R2, 0.60), compared with BEua (R2, 0.56), [XA] (R2, 0.50), and the anion gap (R2, 0.41). CONCLUSIONS AND CLINICAL RELEVANCE: Calculated values for Atot, Ka, and the SIG equation should facilitate application of the strong ion approach to acid-base disturbances in cattle.

Intracellular magnesium concentrations in dogs with gastric dilatation-volvulus.

OBJECTIVE: To quantify and compare intracellular magnesium concentrations (Mgi) in clinically normal dogs (control dogs) and dogs that have gastric dilatation-volvulus (GDV dogs) and to determine whether there is a difference in Mgi and serum magnesium concentrations (Mgs) between GDV dogs with and without cardiac arrhythmias. ANIMALS: 41 control dogs and 21 GDV dogs. PROCEDURE: Rectus abdominis muscle specimens were obtained from control and GDV dogs for determination of Mgi. Blood samples were obtained from GDV dogs for determination of Mgs, and dogs were monitored for 48 hours for cardiac arrhythmias. Muscle specimens were frozen at -40 C, oven dried at 95 C, and digested with concentrated nitric acid. Multielemental analyses were performed by simultaneous/sequential inductively coupled plasma-atomic emission spectroscopy with fixed-cross flow nebulization. The Mg, was standardized to sulfur content to correct for the amount of fat and fascia in the muscle specimen. Mean (+/- SEM) values were recorded in parts per million (ppm). Results-There were no significant differences in Mgi between control (627 +/- 11.1 ppm) and GDV (597 +/- 20.5 ppm) dogs, in Mgi between GDV dogs with (590 +/- 34 ppm) and without (584 +/- 29 ppm) cardiac arrhythmias, and in Mgs between GDV dogs with (1.77 +/- 0.26 ppm) and without (1.51 +/- 0.09 ppm) cardiac arrhythmias. There was no correlation between Mgs and Mgi (R2 = 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that Mg depletion is not pathophysiologically important in dogs with GDV and does not play a role in the cardiac arrhythmias detected in these patients.

[pH, sodium, potassium, magnesium, calcium, phosphate and chloride in the rumen and abomasal contents of cows with abomasal displacement]. / pH, Natrium, Kalium, Magnesium, Kalzium, Phosphat und Chlorid im Pansen- und Labmageninhalt von Kühen mit Labmagenverlagerung.

Ruminal and abomasal contents were collected from cows with left abomasal displacement (L), right abomasal displacement (R-), or abomasal volvulus (R+), before the abomasum was corrected, as well as one and three days later, pH and concentrations of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), phosphate (P), and chloride (Cl) were determined. Results were compared with those from healthy control cattle fed a balanced diet. Ruminal concentrations of Na and Ca were reduced in cattle with abomasal displacement, whereas those of K, P and Cl were increased, and those of Mg and pH remained nearly unchanged. Concentrations of K and P before abomasal correction were lower in cattle with L than in those with R+, and declined after the correction. Concentrations of Cl decreased continuously after the abomasum was corrected in cattle with L, whereas they increased after replacement in cattle with R and declined later. These findings imply that cattle with abomasal displacement took up less feed before surgical correction and that ruminal contents backed up in the rumen, whereby the backup was less with L than with R+, and that the backed-up contents passed on after the abomasum was corrected. The results also indicate that a reflux of abomasal contents into the rumen took place in cattle with all forms of abomasal displacement, whereby with R+ increased amounts of abomasal contents passed into the rumen following correction and were then later passed out. Compared to controls, abomasal concentrations of Cl were increased in cattle with displacement and the concentrations of K, Mg, Ca, and P were reduced. Before abomasal correction, pH was decreased in cattle with L and unchanged in those with R- and R+. The concentrations of Na and K before correction in L were lower than those with R+, whereas the concentrations of K, Mg, Ca, and P were higher. After abomasal correction, the concentrations of Na declined, and those of K, Mg, Ca, and P increased. On the third day after abomasal correction, pH and the concentrations of K, Mg, Ca, and P were lower and the concentrations of Cl higher than in controls. These findings indicate that before abomasal correction in cattle with abomasal displacement secretion from the abomasal glands was increased, abomasal contents backed up in the abomasum, whereby the secretion/backup was less with L than with R+, and that the backed-up contents are passed on after the abomasum is corrected. The findings also suggest that the increased rate of secretion from the abomasal glands or abomasal motility disorders continues on to the third day after abomasal correction.

Effects of gastric distention-volvulus on coronary blood flow and myocardial oxygen consumption in the dog.

Gastric distention-volvulus (GDV; at 50 mm of Hg gastric inflation pressure) was experimentally induced in 8 dogs anesthetized using pentobarbital. Hemodynamic indices including heart rate, mean arterial pressure, cardiac output, and coronary blood flow (4 dogs) were measured during a 20-minute period of GDV and for 10 minutes after decompression. Arterial and coronary venous oxygen tensions were also measured for calculation of myocardial oxygen extraction (7 dogs) and myocardial oxygen consumption (4 dogs). Dogs were monitored for 72 hours postoperatively for the occurrence of arrhythmias, then were euthanatized for gross and histologic examination of the heart. Experimental GDV resulted in significant (P less than 0.05) decreases in cardiac output (89%), mean arterial pressure (45%), and coronary blood flow (50%) compared with control values. Myocardial oxygen extraction increased (30%) and overall myocardial oxygen consumption decreased (50%), compared with control values. Evidence of subendocardial necrosis was seen in 6 dogs, 4 of which had developed ventricular arrhythmias 8 to 24 hours postoperatively.