Effect of tissue processing on assessment of endoscopic intestinal biopsies in dogs and cats.

BACKGROUND: Prior studies failed to detect significant association between hypoalbuminemia and small intestinal lesions. HYPOTHESIS: Use of pictorial templates will enhance consistency of interpathologist interpretation and identification of intestinal lesions associated with hypoalbuminemia. ANIMALS: Tissues from 62 dogs and 25 cats examined as clinical cases at 7 referral veterinary practices in 4 countries. METHODS: Retrospective, observational study. Histopathology slides from sequential cases undergoing endoscopic biopsy were examined by 4 pathologists by pictorial templates. Changes for 9 microscopic features were recorded as normal, mild, moderate or severe, and 2- and 4-point scales were tested for consistency of interpretation. Logistic regression models determined odds ratios (OR) of histologic lesions being associated with hypoalbuminemia while kappa statistics determined agreement between pathologists on histologic lesions. RESULTS: There was poor agreement (kappa = -0.013 to 0.3) between pathologists, and institution of origin of slides had effect (kappa = 1.0 for 3 of 4 lesions on slides from Institution 5) on agreement between pathologists on selected histologic features. Using 2 point as opposed to 4-point grading scale increased agreement between pathologists (maximum kappa = 0.69 using 4-point scale versus maximum kappa = 1.0 using 2-point scale). Significant association (P = .019- .04; 95% OR = 3.14-10.84) between lacteal dilation and hypoalbuminemia was found by 3 pathologists. CONCLUSIONS AND CLINICAL IMPORTANCE: Substantial inconsistency between pathologists remains despite use of pictorial template because of differences in slide processing. Distinguishing between mild and moderate lesions might be important source of the disagreement among pathologists.

A prospective, randomized, double-blinded, placebo-controlled study of human intravenous immunoglobulin for the acute management of presumptive primary immune-mediated thrombocytopenia in dogs.

BACKGROUND: Immune-mediated thrombocytopenia (IMT) is a common hematologic disorder in dogs. Human intravenous immunoglobulin (hIVIG) may have a beneficial effect in canine IMT. HYPOTHESIS: A single hIVIG infusion (0.5 g/kg) in dogs with presumed primary IMT (pIMT) is a safe adjunctive emergency treatment to accelerate platelet count recovery and shorten hospitalization time without increasing the cost of patient care. ANIMALS: Eighteen client-owned dogs with a presumptive diagnosis of pIMT. METHODS: Prospective, randomized, double-blinded, placebo-controlled clinical trial. RESULTS: There were no identifiable immediate or delayed adverse reactions associated with hIVIG administration over a 6-month period. The median platelet count recovery time for the hIVIG group was 3.5 days (mean + or - SD: 3.7 + or - 1.3 days; range, 2-7 days) and 7.5 days (mean + or - SD: 7.8 + or - 3.9 days; range, 3-12 days) for the placebo group. The median duration of hospitalization for hIVIG group was 4 days (mean + or - SD: 4.2 + or - 0.4 days; range, 2-8 days) and 8 days (mean + or - SD: 8.3 + or - 0.6 days; range, 4-12 days) for the placebo group. There was no significant difference between groups with respect to expense of initial patient care, whereas significant reduction in platelet count recovery time (P= .018) and duration of hospitalization (P= .027) were detected in the hIVIG group. CONCLUSIONS AND CLINICAL IMPORTANCE: Compared with corticosteroids alone, adjunctive emergency therapy of a single hIVIG infusion was safe and associated with a significant reduction in platelet count recovery time and duration of hospitalization without increasing the expense of medical care in a small group of dogs with presumed pIMT.

Effect of sample quality on the sensitivity of endoscopic biopsy for detecting gastric and duodenal lesions in dogs and cats.

BACKGROUND: The quality of histopathology slides of endoscopic biopsies from different laboratories varies, but the effect of biopsy quality on outcome is unknown. HYPOTHESIS: The ability to demonstrate a histologic lesion in the stomach or duodenum of a dog or cat is affected by the quality of endoscopic biopsy samples submitted. More endoscopic samples are needed to find a lesion in poor-quality tissue specimens. ANIMALS: Tissues from 99 dogs and 51 cats were examined as clinical cases at 8 veterinary institutions or practices in 5 countries. METHODS: Histopathology slides from sequential cases that underwent endoscopic biopsy were submitted by participating institutions. Quality of the histologic section of tissue (inadequate, marginal, adequate), type of lesion (lymphangiectasia, crypt lesion, villus blunting, cellular infiltrate), and severity of lesion (normal, mild, moderate, severe) were determined. Sensitivity of different quality tissue samples for finding different lesions was determined. RESULTS: Fewer samples were required from dogs for diagnosis as the quality of the sample improved from inadequate to marginal to adequate. Duodenal lesions in cats displayed the same trend except for moderate duodenal infiltrates for which quality of tissue sample made no difference. Gastric lesions in dogs and mild gastric lesions in cats had the same trend, whereas the number of tissue samples needed to diagnose moderately severe gastric lesions in cats was not affected by the quality of tissue sample. CONCLUSIONS AND CLINICAL IMPORTANCE: The quality of endoscopically obtained tissue samples has a profound effect on their sensitivity for identifying certain lesions, and there are differences between biopsies of canine and feline tissues.

Beta-adrenergic agonists regulate KCa channels in airway smooth muscle by cAMP-dependent and -independent mechanisms.

Stimulation of calcium-activated potassium (KCa) channels in airway smooth muscle cells by phosphorylation-dependent and membrane-delimited, G protein actions has been reported (Kume, H. A. Takai, H. Tokuno, and T. Tomita. 1989. Nature [Lond.]. 341:152-154; Kume, H., M. P. Graziano, and M. I. Kotlikoff. 1992. Proc. Natl. Acad. Sci. USA. 89:11051-11055). We show that beta-adrenergic receptor/channel coupling is not affected by inhibition of endogenous ATP, and that activation of KCa channels is stimulated by both alpha S and cAMP-dependent protein kinase (PKA). PKA stimulated channel activity in a dose-dependent fashion with an EC50 of 0.12 U/ml and maximum stimulation of 7.38 +/- 2.04-fold. Application of alpha S to patches near maximally stimulated by PKA significantly increased channel activity to 15.1 +/- 3.65-fold above baseline, providing further evidence for dual regulatory mechanisms and suggesting that the stimulatory actions are independent. Analysis of channel open-time kinetics indicated that isoproterenol and alpha S stimulation of channel activity primarily increased the proportion of longer duration events, whereas PKA stimulation had little effect on the proportion of short and long duration events, but resulted in a significant increase in the duration of the long open-state. cAMP formation during equivalent relaxation of precontracted muscle strips by isoproterenol and forskolin resulted in significantly less cAMP formation by isoproterenol than by forskolin, suggesting that the degree of activation of PKA is not the only determinant of tissue relaxation. We conclude that beta-adrenergic stimulation of KCa channel activity and relaxation of tone in airway smooth muscle occurs, in part, by means independent of cyclic AMP formation.

GABA receptors in the dorsal motor nucleus of the vagus influence feline lower esophageal sphincter and gastric function.

Gamma-aminobutyric acid (GABA) antagonist (bicuculline methiodide, BIC; picrotoxin, PIC) or agonist (muscimol, MUS) microinjections were made into the dorsal motor nucleus of the vagus nerve (DMV), and effects on lower esophageal sphincter pressure (LESP), gastric motility, and gastric acid secretion were determined in chloralose-anesthetized cats. Right or left DMV sites were microinjected with BIC, PIC, MUS, or isotonic tonic saline (140 nl) through a glass micropipette having a tip diameter of 15-21 microns. Esophageal body, LESP, and gastric fundic pressures were measured manometrically. Circular smooth muscle contractions of the antrum and pylorus were recorded with strain-gauge force transducers. Gastric acid secretion was measured every 15 min through a gastric cannula and titrated to pH 7.0. DMV microinjection sites were verified histologically. Direct BIC microinjections (0.275 or 0.550 nmol) into the DMV primarily produced a decrease in LESP (71% of all sites tested), with mean LESP changing from 23.2 +/- 1.7 mmHg to 3.7 +/- 0.7 mmHg (p < 0.01). Tonic LESP increases and phasic LESP contractile activity occurred less frequently. BIC-induced LESP responses were abolished by vagotomy or by microinjections of MUS (0.5 to 10 nmol) into the DMV. Direct PIC microinjection (0.232 nmol) into the DMV produced a pattern of responses similar to those observed with BIC (which were also abolished by vagotomy or by MUS microinjections into the DMV). The antrum and pylorus were also responsive to DMV microinjections of both GABA antagonists. Microinjections of BIC or PIC into the DMV produced increases in gastric circular muscle activity that occurred less frequently than LESP effects, but also were eliminated by vagotomy. The high (0.550 nmol) dose of BIC increased gastric motility significantly more often than the low dose of BIC (p < 0.05). In addition, BIC (0.550 nmol) microinjections into the DMV increased gastric secretory volume (from 0.6 +/- 0.2 to 6.0 +/- 2.5 ml/15 min; p < 0.01) and total titratible acid (from 34.4 +/- 8.9 to 86.0 +/- 19.1 mEq/15 min; p < 0.01), and decreased gastric pH (from 4.63 +/- 0.44 to 3.50 +/- 0.49; p < 0.05). Vagotomy also eliminated the gastric secretory effects of DMV BIC. Direct microinjections of MUS into the DMV also blocked BIC- or PIC-induced changes in gastric motility and/or gastric acid secretion. Isotonic saline microinjected into the DMV did not increase basal or decrease stimulated gastric esophageal motility or gastric secretion. These data indicate that LESP, gastric motility, and gastric secretion are influenced by a tonic DMV inhibition mediated by GABAA receptor stimulation of the DMV. Because disinhibition of these receptors clearly activates the upper gut, future work should focus on identifying the nuclei providing this synaptic input to the DMV that might be involved in the functional regulation of upper gut motor and secretory function.

Cisapride stimulates contraction of idiopathic megacolonic smooth muscle in cats.

We have previously shown that cisapride, a substituted piperidinyl benzamide, stimulates contraction of healthy feline colonic smooth muscle. The purpose of the present investigation was to determine the effect of cisapride on feline idiopathic megacolonic smooth muscle function. Longitudinal smooth muscle strips from ascending and descending colon were obtained from cats with idiopathic megacolon, suspended in a 1.5 mM Ca(2+)-HEPES buffer solution (37 degrees C, 100% O2, pH 7.4), attached to isometric force transducers, and stretched to optimal muscle length (Lo). Control responses were obtained at each muscle site with acetylcholine (10(-8) to 10(-4) M), substance P (10(-11) to 10(-7) M), or potassium chloride (10 to 80 mM). Muscles were then stimulated with cumulative (10(-9) to 10(-6) M) doses of cisapride in the absence or presence of tetrodotoxin (10(-6) M) and atropine (10(-6) M), or in a 0 calcium HEPES buffer solution. In cats with idiopathic megacolon, cisapride stimulated contractions of longitudinal smooth muscle from both the ascending and the descending colon. Cisapride-induced contractions were similar in magnitude to those induced by substance P and acetylcholine in the ascending colon, but were less than those observed in the descending colon. Cisapride-induced contractions in megacolonic smooth muscle were only partially inhibited by tetrodotoxin and atropine, but were virtually abolished by removal of extracellular calcium. We concluded that cisapride-induced contractions of feline megacolonic smooth muscle are largely smooth muscle mediated and dependent on influx of extracellular calcium. Cisapride-induced contractions in megacolonic smooth muscle are only partially dependent on enteric cholinergic nerves. Thus, cisapride may be useful in the treatment of cats with idiopathic megacolon.

Acute pancreatitis in cats with hepatic lipidosis.

The purpose of this study was to characterize the incidence, clinical features, and prognosis of acute pancreatitis in cats with hepatic lipidosis. Of 13 cats histologically diagnosed with hepatic lipidosis between July 1988, and November 1989, 5(38%) were also histologically diagnosed with acute pancreatitis. In cats with hepatic lipidosis alone, the signalment, history, physical examination, and clinicopathologic findings were generally indistinguishable from those of cats with concurrent acute pancreatitis except that cats with acute pancreatitis were more likely to be cachectic and to have coagulation abnormalities. Hepatomegaly was seen on abdominal radiographs in both groups. Of the 5 cats with concurrent acute pancreatitis, abdominal ultrasonography detected 1 cat with a hypoechoic pancreas and 5 with peritoneal effusion; those abnormalities were not seen in cats without concurrent acute pancreatitis. Cats with concurrent acute pancreatitis had only a 20% recovery rate, compared with a 50% recovery rate in cats with hepatic lipidosis alone. We conclude that cats with hepatic lipidosis should be rigorously evaluated for concurrent acute pancreatitis because of 1) the rate of disease coincidence, 2) the inability of signalment, history, physical examination, and clinicopathologic findings to adequately distinguish between hepatic lipidosis and acute pancreatitis, 3) the worse prognosis associated with concurrent acute pancreatitis, and 4) the opposing nutritional strategies for hepatic lipidosis and acute pancreatitis.

Congenital esophageal hiatal hernia in the Chinese shar-pei dog.

Esophageal hiatal hernia was diagnosed in 11 young Chinese Shar-Pei dogs between October 1985 and July 1991. The dogs ranged in age from 2 to 11 months and included 3 females and 8 males. The most common clinical signs were regurgitation, vomiting, and hypersalivation. Physical examination was normal in 6 dogs; abnormal physical examination findings in the other 5 dogs included fever, dehydration, hypersalivation, and pulmonary wheezes and crackles. Laboratory evaluation was significant only for neutrophilia in 5 dogs. A diagnosis of hiatal hernia was made on the basis of survey thoracic radiographic and/or barium esophagram findings of displacement of the esophagogastric junction and stomach into the thoracic cavity; the diagnosis was confirmed by surgery in 9 dogs and at necropsy in 2 dogs. Megaesophagus (n = 7), gastroesophageal reflux (n = 4), and esophageal hypomotility (n = 1) were additional findings in some dogs. Aspiration pneumonia was diagnosed in 7 of the dogs. Medical therapies formulated for the therapy of presumed reflux esophagitis generally failed to resolve the clinical signs associated with the hiatal hernia. Hiatal herniae were surgically repaired in 9 of the Shar-Peis by various combinations of diaphragmatic crural apposition, fixation of the esophagus to the diaphragmatic crus (esophagopexy), and left fundic tube gastropexy. Eight of the animals survived surgery, six of which have been asymptomatic since surgery (19 to 36 months). The megaesophagus, esophageal hypomotility, and bronchopneumonia resolved in all of these dogs.

Effects of cisapride on feline colonic smooth muscle function.

OBJECTIVE: To determine the effects of cisapride on feline colonic smooth muscle function. DESIGN: In vitro smooth muscle mechanical measurements. ANIMALS: Intact colon was obtained from healthy 2- or 3-year-old cats. PROCEDURE: Longitudinal smooth muscle strips from proximal and distal portions of feline colon were suspended in physiologic buffer solution (37 C. 100% O2, pH 7.4), attached to isometric force transducers, and stretched to optimal muscle length. Control responses were obtained at each muscle site with acetylcholine (10(-8) to 10(-4) M), cholecystokinin (10(-11) to 10(-7) M), substance P (10(-21) to 10(-7) M), or neurotensin (10(-11) to 10(-7) M). Muscles were then stimulated with cumulative (10(-9) to 10(-6) M) or bolus (10(-6) M) doses of cisapride in the absence or presence of tetrodotoxin (10(-5) M) and atropine (10(-6) M), nifedipine (10(-6) M), or calcium-free buffer solution. RESULTS: Cisapride stimulated contractions of longitudinal smooth muscle from proximal and distal portions of feline colon that were similar in magnitude to contractions induced by substance P and neurotensin. Cisapride contractions were only partially inhibited by tetrodotoxin (10(-6) M) and atropine (10(-6) M), suggesting that cisapride responses are only partially dependent on enteric cholinergic nerves. Nifedipine (10(-6)M) inhibited the maximal contraction to cisapride (10(-6) M) by approximately 80%. Removal of extracellular calcium did not inhibit cisapride contractions to a greater extent than did inhibition by nifedipine, indicating that calcium influx through voltage-dependent calcium channels was predominantly responsible for the dependence of the cisapride contraction on extracellular calcium. CONCLUSIONS: Cisapride-induced contractions of feline colonic smooth muscle are largely smooth muscle-mediated and dependent on calcium influx, and are only partially dependent on enteric cholinergic nerves. CLINICAL RELEVANCE: Cisapride may be useful in the treatment of feline colonic motility disorders.

Alterations in colonic smooth muscle function in cats with idiopathic megacolon.

OBJECTIVE: To determine whether colonic smooth muscle dysfunction is involved in the pathogenesis of idiopathic megacolon in cats. DESIGN: In vitro smooth muscle mechanical measurements. ANIMALS: Colon from healthy cats and cats with idiopathic megacolon. PROCEDURE: Colonic smooth muscle strips were suspended in physiologic buffer solution, attached to isometric force transducers, and contracted with acetylcholine (ACh; 10(-9) to 10(-4)M), substance P (SP; 10(-10) to 10(-6)M), cholecystokinin (CCK; 10(-11) to 10(-8)M), potassium chloride (KCl; 10 to 80 mM), or electrical field stimulation (EFS; 25 V, 1 to 30 Hz, 0.5-millisecond duration). Isometric stress responses were compared with those obtained from healthy controls. Colonic smooth muscle strips were also evaluated histologically for neuronal and smooth muscle cell morphology. RESULTS: Passive isometric stress was not altered, but the active isometric stress responses of megacolon smooth muscle to ACh, SP, CCK, KCl, and EFS were significantly (P < 0.05) diminished, compared with healthy controls. Differences were observed in longitudinal and circular smooth muscle from proximal and distal portions of the colon. Histologic evaluation revealed few abnormalities of smooth muscle cells or of myenteric or submucosal plexus neurons. The contractile response of megacolon smooth muscle to EFS, and the inhibition of this response by tetrodotoxin, suggest that myenteric and submucosal plexus neurons in megacolon smooth muscle are functional. CONCLUSIONS: Idiopathic megacolon is a generalized dysfunction of colonic smooth muscle in cats. The diminished isometric stress responses to receptor occupancy (ACh, SP, and CCK) and membrane depolarization (KCl) further suggest that the disorder involves disturbance in the activation of smooth muscle myofilaments.

Effects of age, sex, reproductive status, and hospitalization on serum alpha 1-antitrypsin concentration in dogs.

We performed a study to determine a reference range for serum alpha 1-antitrypsin (alpha 1AT) in dogs by specific immunoassay; to evaluate whether serum alpha 1AT concentration varied with age, sex, or reproductive status in healthy dogs; and to investigate whether the serum alpha 1AT concentration in hospitalized dogs differed from that of healthy, nonhospitalized dogs. Serum alpha 1AT was quantitated by radial gel immuno-diffusion for 60 healthy dogs and 311 hospitalized dogs. In healthy dogs, serum alpha 1AT concentration was 2.33 +/- 0.41 mg/ml (mean +/- SD), yielding a reference range (mean +/- 2 SD) of 1.51 to 3.15 mg/ml. A correlation was not found between serum alpha 1AT concentration and age in healthy dogs. The serum alpha 1AT concentration (mean +/- SEM mg/ml) was significantly higher in healthy, sexually intact females (2.64 +/- 0.1) than in healthy, spayed females (2.22 +/- 0.12; P < 0.004); healthy, sexually intact males (2.14 +/- 0.1; P < 0.0006); and healthy, and castrated males (2.25 +/- 0.14; P < 0.02). Hospitalized, sexually intact females had a lower serum alpha 1AT concentration (1.93 +/- 0.07) than healthy, sexually intact females (2.64 +/- 0.1; P < 0.0002). Likewise, the serum alpha 1AT concentration in hospitalized, sexually intact males (1.92 +/- 0.04) was less than in healthy, sexually intact males (2.14 +/- 0.1; P < 0.04). A difference in alpha 1AT concentration was not found between healthy and hospitalized, neutered dogs.

Evaluation of intestinal carbohydrate malabsorption in the dog by pulmonary hydrogen gas excretion.

Breath H2 was measured for the assessment of intestinal carbohydrate absorption in healthy, fasted dogs before and after the ingestion of carbohydrate test meals. The dogs were fed lactulose, xylose, glucose, a hypoallergenic diet, or the hypoallergenic diet supplemented with rice, corn, or wheat flour. Breath samples for H2 analysis were collected by an interval-sampling technique during tidal breathing and were analyzed by thermal conductivity gas chromatography. Pulmonary H2 excretion in fasted dogs never exceeded 1 part per million (molecules of H2 per 10(6) molecules of air). Breath H2 excretion after the ingestion of 12.5 g of glucose, a completely absorbed monosaccharide, was not significantly different (P greater than 0.05) from that during fasting; however, ingestion of 12.5 g of xylose, an incompletely absorbed pentose, significantly increased (P less than 0.001) breath H2 excretion. After ingestion of 12.5, 25, or 50 g of lactulose, a nonabsorbable disaccharide, pulmonary H2 excretion increased significantly (P less than 0.001) over fasting amounts and the increases were different (P less than 0.001) from one another. Increases in breath H2 excretion correlated (r = 0.97) with increases in lactulose dose. Breath H2 excretion after the ingestion of the hypoallergenic diet did not significantly (P greater than 0.05) differ from that after fasting. The addition of rice flour to this diet did not significantly (P greater than 0.05) increase H2 production. However, the addition of wheat or corn flour to this diet significantly (P less than 0.001) increased breath H2 excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Digestion of bentiromide and absorption of xylose in healthy cats and absorption of xylose in cats with infiltrative intestinal disease.

The digestion of bentiromide and the absorption of D-xylose was measured in 17 clinically healthy cats. The plasma xylose concentrations of the healthy cats were compared with values from 9 cats with diffuse infiltrative intestinal disease. The cats were administered 16.7 mg of bentiromide/kg and 0.5 g of xylose/kg via a stomach tube. Plasma samples were obtained before administration and 30, 60, 90, and 120 minutes after administration. The maximum mean plasma p-aminobenzoic acid concentration occurred at 60 minutes, with a value of 386 +/- 134 micrograms/dl (mean +/- SD). The maximum mean plasma xylose concentration also occurred at 60 minutes, with a value of 26.0 +/- 9.2 mg/dl. Plasma concentrations of p-aminobenzoic acid and xylose were lower in healthy cats than those reported for healthy dogs. There was no significant difference between xylose concentrations in healthy cats and cats with infiltrative intestinal disease.

Granulomatous hepatitis in dogs: nine cases (1987-1990).

Granulomatous hepatitis (GH) is an uncommon histopathologic diagnosis in dogs. On the basis of clinical reports, fungal infections appear to be the most common cause of GH in dogs, but many other potential causes have been identified. The medical records and histopathologic findings for 9 dogs with GH were reviewed to identify additional specific causes of GH in dogs. Diseases associated with GH included intestinal lymphangiectasia (n = 2), lymphosarcoma (n = 1), histiocytosis (n = 1), dirofilariasis (n = 1), and histoplasmosis (n = 1). In 1 dog, no other disease process was identified. Of the remaining 2 dogs, 1 had concurrent granulomatous pneumonitis of unknown cause, and the other had periportal hepatitis and temporal muscle wasting. All 9 dogs with GH had clinical evidence of liver disease, such as hepatomegaly, icterus, and ascites, or had high serum alkaline phosphatase and alanine aminotransferase activity. Because of the wide variety of potential causes of GH in dogs, an accurate diagnosis should be sought so that appropriate treatment can be chosen and an accurate prognosis given.

Canine gastric dilatation/volvulus syndrome in a veterinary critical care unit: 295 cases (1986-1992).

Two hundred ninety-five case records were included in an analysis of dogs treated by a standardized protocol for gastric dilatation/volvulus syndrome between 1986 and 1992. A breed predisposition was demonstrated for Great Danes, German Shepherd Dogs, large mixed-breed dogs, and Standard Poodles. One hundred and ninety-three dogs had gastric dilatation and volvulus (GDV) confirmed at surgery, 66 had simple gastric dilatation (GD), and 36 others had gastric dilatation but volvulus could not be proved or disproved (GD +/- V). Among dogs with GDV, the fatality rate was 15% (29/193). Twenty-six (13.5%) dogs with GDV underwent partial gastrectomy, and 8 (31%) died or were subsequently euthanatized. In comparing the group of dogs with GDV that survived to those that died, there were no statistical differences in the age of dog, time between onset of clinical signs and admission, time from admission to surgery, or duration of anesthesia. Cardiac arrhythmias were detected in 40% (78/193) of the dogs with GDV. There also was no statistical correlation between development of a cardiac arrhythmia and outcome in dogs with GDV. The causes of death in dogs with GDV were multiple and varied; presumed gastric necrosis was a common reason for intraoperative euthanasia (11 dogs). Among dogs with GD or GD +/- V, the fatality rate was 0.9% (1/102).

Hepatic abscesses in dogs: 14 cases (1982-1994).

OBJECTIVES: To determine typical clinical signs and clinicopathologic findings in dogs with hepatic abscesses, to assess outcome of treatment, and to evaluate the role that abdominal ultrasonography has in the diagnosis of hepatic abscesses in dogs and in monitoring response to treatment. DESIGN: Retrospective case series. ANIMALS: 14 dogs with hepatic abscesses. RESULTS: Anorexia and lethargy were the most common historical complaints, followed by vomiting and diarrhea. Physical abnormalities included fever, dehydration, signs of abdominal pain, hepatomegaly, and mucosal bleeding. Hematologic abnormalities included leukocytosis with neutrophilia, mild to moderate thrombocytopenia, and mild anemia. Serum biochemical abnormalities included high alkaline phosphatase and alanine aminotransferase activities and high bilirubin concentration; hypoalbuminemia and prolonged coagulation values were also reported. Abdominal radiography revealed hepatomegaly, poor abdominal detail, a hepatic mass, or splenomegaly in 9 dogs. Thoracic radiography revealed alveolar consolidation or mixed bronchial/interstitial pulmonary patterns in 6 dogs. Hypoechoic, heteroechoic, or hyperechoic masses were identified in all dogs in which ultrasonography was performed. Escherichia coli, Clostridium sp, Klebsiella pneumoniae, Enterococcus sp, Staphylococcus epidermidis, and S intermedius were the most common bacteria isolated from hepatic abscesses. Concurrent infections were identified in the biliary tract, spleen, blood, endocardium, lung, prostate gland, peritoneum, lymph nodes, salivary gland, or brain of several dogs. Seven dogs died or were euthanatized before definitive treatment could be initiated. One dog was successfully treated with antibiotics and was alive 12 months after medical treatment. Six dogs were treated surgically (ie, full or partial liver lobectomy, drainage, abdominal lavage) and medically (ie, antibiotic administration). Five of these dogs survived and were alive 12 months after surgery. Ultrasonography was used to monitor response to treatment in several dogs. CLINICAL IMPLICATIONS: Hepatic abscesses are rare in dogs, but the clinical signs and clinicopathologic findings are similar to other inflammatory hepatic disease. Ultrasonography revealed abnormalities in all animals in which imaging studies were performed, and was successfully used to monitor response to treatment in several dogs. Medical and surgical treatments were used successfully to treat hepatic abscesses in dogs.

Use of pulmonary hydrogen gas excretion to detect carbohydrate malabsorption in dogs.

Pulmonary H2 excretion was measured in 10 healthy dogs, in 6 dogs with pancreatic exocrine insufficiency, and in 6 dogs with chronic small intestinal disease. Concentration of expired H2 in fasted healthy dogs was 0.9 +/- 0.1 ppm (mean +/- SEM) and peak H2 concentration of 1.4 +/- 0.2 ppm was detected up to 8 hours after feeding. Dogs with pancreatic exocrine insufficiency had fasting expired H2 concentrations of 3.3 +/- 0.9 ppm, which increased to a mean peak H2 concentration of 28.8 +/- 2.0 ppm 6.5 hours after feeding. Following xylose administration, expired H2 concentrations increased from fasting concentrations of 3.6 +/- 0.9 ppm to peak at 19.0 +/- 2.0 ppm in 1.5 hours. Blood xylose concentrations were diagnostic for carbohydrate malabsorption in 4 of 6 dogs with pancreatic exocrine insufficiency. Plasma p-aminobenzoic acid concentration identified bentiromide maldigestion in all dogs with pancreatic exocrine insufficiency. In 3 pancreatic exocrine insufficient dogs tested, pancreatic enzyme replacement therapy partially corrected carbohydrate malabsorption. Fasting expired H2 concentration was 5.3 +/- 1.3 ppm in dogs with chronic small intestinal disease and increased to a peak H2 of 72.2 +/- 18.0 ppm 7 hours after feeding. Following administration of xylose to dogs with chronic small intestinal disease, fasting expired H2 concentration increased from 3.0 +/- 1.0 ppm to a peak of 35.5 +/- 7.2 ppm at 2 hours. Blood xylose concentration was abnormal in only 2 of 6 dogs with chronic small intestinal disease. Results of these studies indicate that expired H2 analysis can identify carbohydrate malabsorption in dogs with pancreatic exocrine insufficiency or chronic small intestinal disease, and that pulmonary H2 testing is more sensitive than xylose absorption testing for the identification of carbohydrate malabsorption.

Serum alpha 1-antitrypsin concentration in dogs with panniculitis.

OBJECTIVE: To measure serum alpha 1-antitrypsin (alpha 1AT) concentration in dogs with histologically confirmed panniculitis to determine whether serum deficiency could cause or exacerbate panniculitis in dogs. DESIGN: Cross-sectional, descriptive study. ANIMALS: 9 dogs (5 with multiple lesions and 4 with solitary lesions). PROCEDURE: Serum samples were obtained by means of cephalic or jugular venipuncture and frozen at -20 C until assayed. Serum alpha 1AT concentration was measured by means of radial gel immunodiffusion. RESULTS: In all dogs, serum alpha 1AT concentration was within the previously established reference range. CLINICAL IMPLICATIONS: In the small number of-dogs studied, panniculitis was not associated with serum alpha 1AT deficiency.

Risk factors for acquired megaesophagus in dogs.

OBJECTIVE: To identify risk factors associated with acquired megaesophagus in dogs. DESIGN: Case-control study. ANIMALS: 136 dogs with acquired megaesophagus (case dogs); 272 dogs from the general hospital population and 151 dogs that underwent thyroid-stimulating hormone response tests (control dogs). All dogs were more than 6 months old. PROCEDURE: Medical records of dogs in which megaesophagus was diagnosed during a 10-year period were reviewed. Inclusion criteria included regurgitation or vomiting, onset of clinical signs at more than 6 months of age, and radiographic evidence of generalized esophageal dilatation. Dogs with intra- or extraesophageal obstructive disease, brain stem disease, or neck trauma were excluded from analyses. Statistical analyses included odds ratios, 95% confidence intervals, and two-tailed t-tests. Control dogs were frequency matched to case dogs on the basis of year of diagnosis. RESULTS: Dogs with megaesophagus ranged from 0.75 to 18 years old (mean, 8.1 years) and were significantly older and heavier than control dogs. More males than females were affected, but sex and reproductive status were not associated with megaesophagus. German Shepherd Dogs, Golden Retrievers, and Irish Setters were at increased risk for developing megaesophagus. Peripheral neuropathies, laryngeal paralysis, acquired myasthenia gravis, esophagitis, and chronic or recurrent gastric dilatation with or without volvulus were associated with an increased risk of developing megaesophagus. Hypothyroidism was not associated with megaesophagus. CLINICAL IMPLICATIONS: Dogs with acquired megaesophagus should be evaluated for peripheral neuropathies, laryngeal paralysis, acquired myasthenia gravis, esophagitis, and chronic or recurrent gastric dilatation with or without volvulus. These dogs may be evaluated for hypothyroidism; however, this study did not reveal a clear association between hypothyroidism and acquired megaesophagus.