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Summary

Medical records of 52 dogs born with portal venous anomalies (PVA) were reviewed and separated into 2 groups, based on anatomic location of the shunt (intrahepatic vs extrahepatic). Statistical analysis was used to compare the groups with respect to presurgical clinicopathologic data, as well as to compare presurgical clinicopathologic data with postoperative mortality.

Three presurgical predictors of location were identified. Mean body weight at admission was statistically different (P = 0.0001) between dogs with an intrahepatic PVA (mean, 15 kg) and those with an extrahepatic PVA (mean, 4.8 kg). Blood glucose concentration was significantly (P = 0.028) higher in dogs with an intrahepatic PVA (mean, 99.8 mg/dl) than in dogs with an extrahepatic PVA (mean, 85.1 mg/dl). The third significant (P = 0.036) predictor of location was degree of elevation of serum alkaline phosphatase concentration. The intrahepatic location resulted in a concentration 3.2 times that of the reference value, whereas an extrahepatic location resulted in a 1.7 times increase.

Two predictors of early postoperative mortality were identified. In comparing the 2 groups, significant differences in PCV before surgery (P = 0.04) and in rectal temperature after surgery (P = 0.002) were found. Dogs that survived had a mean presurgical PCV of 36% and a mean postoperative rectal temperature of 35.7 C, whereas nonsurvivors had a mean presurgical PCV of 40.6% and a mean temperature of 34.3 C. There was no significant difference between nonsurvivors and survivors with respect to postligation portal pressure or change in portal pressure after ligation. Overall mortality was 15%.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the effect of oral administration of a silibinin-phosphatidylcholine complex (SPC) on oxidative stress in leukocytes and granulocyte function in healthy cats.

Animals—10 purpose-bred adult cats.

Procedures—Cats were administered SPC (10 mg/kg/d) orally for 5 days; blood samples were collected prior to and immediately after the 5-day treatment period. Leukocytes were incubated with monochlorobimane for detection of reduced glutathione (GSH) via flow cytometry. Leukocytes were also incubated with dihydrorhodamine 123 and mixed with Escherichia coli conjugated to a fluorescent marker to measure E coli phagocytosis and the subsequent oxidative burst via flow cytometry. Activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase, along with the reduced glutathione-to-oxidized glutathione (GSH:GSSG) ratio and a measure of lipid peroxidation (malondialdehyde concentration [Mmol/L of blood]), were measured spectrophotometrically.

Results—The mean fluorescence intensity (MFI), representing GSH content, increased significantly in feline lymphocytes and granulocytes following 5 days of oral administration of SPC. Mean ± SD lymphocyte MFI significantly increased from 27.8 ± 9.0 to 39.6 ± 6.7, and the granulocyte MFI increased from 508.6 ± 135.6 to 612.1 ± 122.9. Following 5 days of SPC administration, the percentage of phagocytic cells that were responding optimally significantly increased (from 37 ± 11.8% to 45 ± 17.5%). Other measures of oxidative stress did not change significantly.

Conclusions and Clinical Relevance—In cats, oral administration of supplemental SPC appears to increase granulocyte GSH content and phagocytic function, both of which would be potentially beneficial in cats with diseases associated with oxidative stress.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate changes in pH of peritoneal fluid associated with CO2 insufflation during laparoscopy in dogs.

Animals—13 client-owned dogs and 10 purpose-bred teaching dogs.

Procedures—Laparotomy was performed on control dogs; peritoneal fluid pH was mea-sured at time of incision of the abdominal cavity (time 0) and 30 minutes later. Laparoscopic insufflation with CO2 was performed and routine laparoscopic procedures conducted on the teaching dogs. Insufflation pressure was limited to 12 mm Hg. Intraperitoneal fluid pH was measured by use of pH indicator paper at 4 time points. Arterial blood gas analysis was performed at the same time points.

Results—Peritoneal fluid pH did not change significantly between 0 and 30 minutes in the control dogs. For dogs with CO2 insufflation, measurements obtained were a mean of 8.5, 24.5, 44.5, and 72.0 minutes after insufflation. The pH of peritoneal fluid decreased signifi-cantly between the first (7.825 ± 0.350) and second (7.672 ± 0.366) time point. Blood pH decreased significantly between the first (7.343 ± 0.078), third (7.235 ± 0.042), and fourth (7.225 ± 0.038) time points. The PaCO2 increased significantly between the first (39.9 ± 9.8 mm Hg) and fourth (54.6 ± 4.4 mm Hg) time points. Base excess decreased significantly between the first and all subsequent time points.

Conclusions and Clinical Relevance—Pneumoperitoneum attributable to CO2 insufflation caused a mild and transient decrease in peritoneal fluid pH in dogs. Changes in peritoneal fluid associated with CO2 insufflation in dogs were similar to those in other animals.

Full access
in American Journal of Veterinary Research

SUMMARY

To evaluate the sensitivity and specificity of 2 commercial test kits for detection of occult blood in canine feces, various volumes of blood were administered to 6 dogs via orogastric tube. Blood volumes tested were chosen on the basis of hemoglobin quantities of 5, 10, 20, 200, 350, and 500 mg of hemoglobin/kg of body weight. Fecal specimens were collected twice daily and analyzed separately by 2 observers for the presence of occult blood by use of modified guaiac and orthotolodine tablet tests, and for melena by visual inspection. Five dogs given blood at the rate of 500 mg of hemoglobin/kg and 1 dog given blood at the rate of 350 mg of hemoglobin/kg developed melena. Results of both occult blood tests were positive in 2 of 6 dogs given blood at the rate of 5 mg of hemoglobin/kg. Five of 6, and 4 of 6 dogs given blood at the rate of 10 mg hemoglobin/kg had positive test results by modified guaiac and orthotolodine methods, respectively. Results of both methods were positive in all dogs given blood at the rate of 20 mg of hemoglobin/kg. There was 86% agreement between the 2 observers’ results for the modified guaiac method, and 78% agreement for the orthotolodine method. There was 77% agreement of results between the 2 test methods. Gastrointestinal transit time decreased with increasing volumes of blood. Occult blood testing was found to be useful for detection of blood in feces at volumes 20 to 50 times less than that required to cause melena.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the oral bioavailability, single and multidose pharmacokinetics, and safety of silibinin, a milk thistle derivative, in healthy horses.

Animals—9 healthy horses.

Procedures—Horses were initially administered silibinin IV and silibinin phospholipid orally in feed and via nasogastric tube. Five horses then consumed increasing orally administered doses of silibinin phospholipid during 4 nonconsecutive weeks (0 mg/kg, 6.5 mg/kg, 13 mg/kg, and 26 mg/kg of body weight, twice daily for 7 days each week).

Results—Bioavailability of orally administered silibinin phospholipid was 0.6% PO in feed and 2.9% via nasogastric tube. During the multidose phase, silibinin had nonlinear pharmacokinetics. Despite this, silibinin did not accumulate when given twice daily for 7 days at the evaluated doses. Dose-limiting toxicosis was not observed.

Conclusions and Clinical Relevance—Silibinin phospholipid was safe, although poorly bio-available, in horses. Further study is indicated in horses with hepatic disease.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate antioxidant capacity and inflammatory cytokine gene expression in horses fed silibinin complexed with phospholipid.

Animals—5 healthy horses.

Procedures—Horses consumed increasing orally administered doses of silibinin phospholipid during 4 nonconsecutive weeks (0 mg/kg, 6.5 mg/kg, 13 mg/kg, and 26 mg/kg of body weight, twice daily for 7 days each week). Dose-related changes in plasma antioxidant capacity, peripheral blood cell glutathione concentration and antioxidant enzyme activities, and blood cytokine gene expression were evaluated.

Results—Plasma antioxidant capacity increased throughout the study period with increasing dose. Red blood cell nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase I activity decreased significantly with increasing doses of silibinin phospholipid. No significant differences were identified in glutathione peroxidase activity, reduced glutathione or oxidized glutathione concentrations, or expression of tumor necrosis factor α, interleukin-1, or interleukin-2.

Conclusions and Clinical Relevance—Minor alterations in antioxidant capacity of healthy horses that consumed silibinin phospholipid occurred and suggest that further study in horses with liver disease is indicated.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether results of histologic examination of hepatic biopsy samples could be used as an indicator of survival time in dogs that underwent surgical correction of a congenital portosystemic shunt (PSS).

Design—Retrospective case series.

Animals—64 dogs that underwent exploratory laparotomy for an extrahepatic (n = 39) or intrahepatic (25) congenital PSS.

Procedures—All H&E-stained histologic slides of hepatic biopsy samples obtained at the time of surgery were reviewed by a single individual, and severity of histologic abnormalities (ie, arteriolar hyperplasia, biliary hyperplasia, fibrosis, cell swelling, lipidosis, lymphoplasmacytic cholangiohepatitis, suppurative cholangiohepatitis, lipid granulomas, and dilated sinusoids) was graded. A Cox proportional hazards regression model was used to determine whether each histologic feature was associated with survival time.

Results—Median follow-up time was 35.7 months, and median survival time was 50.6 months. Thirty-eight dogs were alive at the time of final follow-up; 15 had died of causes associated with the PSS, including 4 that died immediately after surgery; 3 had died of unrelated causes; and 8 were lost to follow-up. None of the histologic features examined were significantly associated with survival time.

Conclusions and Clinical Relevance—Findings suggested that results of histologic examination of hepatic biopsy samples obtained at the time of surgery cannot be used to predict long-term outcome in dogs undergoing surgical correction of a PSS.

Full access
in Journal of the American Veterinary Medical Association

Abstract

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.

Full access
in American Journal of Veterinary Research

Abstract

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.

Open access
in American Journal of Veterinary Research