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Abstract

Objective—To examine cyclooxygenase (COX) expression in canine platelets and Madin-Darby canine kidney (MDCK) cells in culture.

Sample Population—Canine platelets and MDCK cells.

Procedure—Total RNA was recovered from isolated canine platelets and MDCK cells. Northern blot analysis and reverse transcription-polymerase chain reaction (RTPCR), using complementary DNA probes and primers designed from the human COX sequences, were used to determine COX-1 and -2 (cyclooxygenase isoforms 1 and 2) messenger RNA (mRNA) expression.

Results—Following northern blot analysis, canine platelets were found to express only the 2.8-kb COX- 1 transcript; COX-2 was not detected. Canine MDCK cells expressed the 4.5-kb COX-2 transcript, in addition to the 2.8-kb COX-1 transcript. A single DNA band of 270 base pairs was identified following gel electrophoresis of the product obtained from RT-PCR of mRNA from canine platelets. Sequencing revealed that this PCR product was 90% homologous to a portion of the human COX-1 gene (Genbank M59979).

Conclusions and Clinical Relevance—Detection of COX-1 by RT-PCR of RNA obtained from canine platelets is a novel finding. The 90% homology of the PCR product with the human sequence suggests strong conservation between the canine and human COX-1 gene. Cloning and sequencing of the canine gene will be required to fully characterize homologous regions. Because of the importance of COX in the inflammatory process and as a potential target of currently available nonsteroidal anti-inflammatory drugs (NSAID), a better understanding of canine COX may improve our ability to use NSAID appropriately, achieve efficacy, and avoid potential adverse drug effects in dogs. (Am J Vet Res 2000;61:1512–1516)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine effects of therapeutic dosages of aspirin, carprofen, deracoxib, and meloxicam on platelet function and systemic prostaglandin concentrations in healthy dogs.

Animals—10 hound-crossbred dogs.

Procedures—Aspirin (10 mg/kg, PO, q 12 h), carprofen (4.4 mg/kg, PO, q 24 h), deracoxib (2 mg/kg, PO, q 24 h), meloxicam (0.1 mg/kg, PO, q 24 h), and a placebo were administered for 7 days in a random order to each of 10 healthy dogs; there was a 21-day washout period between subsequent treatments. One-stage prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration, and plasma concentrations of thromboxane (TX)B2 and 6-keto prostaglandin (PG)F were measured before and after treatment administration. Platelet function was assessed by use of a platelet-function analyzer and aggregation.

Results—Aspirin, carprofen, and meloxicam did not significantly affect platelet function. Deracoxib caused a mild decrease in platelet aggregation induced by 50μM ADP. Platelet number, Hct, PT, aPTT, and plasma TXB2 and 6-keto PGF concentrations were unchanged after NSAID administration. Meloxicam administration resulted in a significant decrease in fibrinogen concentration, but results remained within the laboratory reference interval.

Conclusions and Clinical Relevance—Oral administration of commonly used NSAIDs at therapeutic dosages in healthy dogs did not alter plasma TXB2 and 6-keto PGF concentrations. Deracoxib administration resulted in a minor abnormality in platelet aggregation. Anti-inflammatory doses of aspirin did not affect platelet function as measured by use of optical aggregometry and a platelet-function analyzer. Further evaluation of the effects of aspirin and cyclooxygenase-2–selective inhibitors on hemostasis should be performed.

Full access
in American Journal of Veterinary Research

Abstract

Objective

To evaluate cardiovascular effects of epidurally administered oxymorphone (OXY) and an OXY-bupivacaine combination (O/B) in halothaneanesthetized dogs.

Animals

6 dogs.

Procedure

In a randomized crossover design study, dogs were anesthetized with halothane and given OXY, O/B, and saline solution (SAL). Eucapnia and end-tidal halothane concentration of 1.2% were established. Heart rate (HR), systemic and pulmonary arterial pressures, central venous pressure (CVP), and cardiac output were measured at baseline and 5, 15, 30, 45, 60, and 75 minutes after treatment. At 90 minutes, glycopyrrolate was administered IV, and measurements were repeated at 95 minutes. Cardiac index (CI), stroke volume, stroke index, systemic vascular resistance (SVR), and left ventricular work were calculated. End-tidal halothane concentration was decreased to 0.8% from 17 to 45 minutes and to 0.5% from 47 to 95 minutes for OXY and O/B, where-as for SAL, it was maintained at 1.5 and 1.2%, respectively. Samples were obtained at 0, 2, 5, 15, 30, 45, 60, and 95 minutes for measurement of serum opiate concentration and comparison with values after IM administration of OXY.

Results

HR decreased, but CVP and SVR increased in response to OXY and O/B. These changes were reversed after IV administration of glycopyrrolate, resulting in significant increase in CI, compared with that in response to SAL. Serum opiate concentration increased markedly and peaked within 15 minutes after OXY and O/B administration but did not differ from values after IM administration.

Conclusions

Epidural administration of OXY results in rapid systemic uptake and decreased HR. Glycopyrrolate administration improves HR, resulting in improved CI at equipotent halothane concentrations. (Am J Vet Res 1999;60:194–200)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine the capacity of pulmonary mast cells (PMC) to degranulate in response to various potential allergens and other secretagogues in horses with recurrent airway obstruction (heaves) and clinically normal horses before and after exposure to moldy hay.

Animals

5 horses with heaves and 5 clinically normal horses.

Procedures

Heaves was characterized as an increased clinical respiratory score and maximum change in transpulmonary pressure of > 20 cm H2O after exposure. Bronchoalveolar lavage was performed during each period. Washed and resuspended cells were exposed for 20 minutes at 37 C with whole reconstituted freeze-dried preparations of Aspergillus fumigatus, Alternaria tenuis, and Ambrosia elation, fungal extracts of Aspergillus fumigatus, Alternaria tenuis, and Micropolyspora faeni; A23187; and compound 48/80. Histamine release (HR) was used as a marker of degranulation.

Results

Compared with clinically normal horses, HR was significantly greater from PMC from horses with heaves during remission and exacerbation in response to whole preparations and extracts of Aspergillus fumigatus and whole preparations of Alternarla tenuis. Extracts of Alternaria tenuis caused significantly greater HR from PMC from horses with heaves during exacerbation. Histamine was also released from PMC in response to A23187 and to changes in osmolality of the medium, but only as a result of cell lysis by compound 48/80.

Conclusions

Increased degranulation of PMC after antigenic challenge may contribute to the pathogenesis of heaves in horses.

Clinical Relevance

Strategies for prevention and treatment that attenuate degranulation of PMC may assist in the clinical management of horses with heaves. (Am J Vet Res 1999;60:841–847)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To identify the normal gastric acid secretion profile in dogs and determine the degree of gastric acid suppression associated with 4 gastric acid suppressants.

Animals—12 healthy Beagles.

Procedure—Intragastric pH was measured continuously for 24-hour periods with a digital recording system placed via a gastrostomy tube. Baseline measurements were obtained when food was withheld and when dogs were fed a standard diet. Dogs were then treated with ranitidine (2 mg/kg, IV, q 12 h), famotidine (0.5 mg/kg, IV, q 12 h), pantoprazole (1 mg/kg, IV, q 24 h), omeprazole (1 mg/kg, PO, q 24 h), or saline solution for 7 days; intragastric pH was recorded on days 0, 2, and 6. Subsequently, the effects of administering famotidine (0.5 mg/kg, IV, q 8 h; 6 dogs) and omeprazole as a suspension (1 mg/kg, PO, q 12 h; 6 dogs) were evaluated. Median 24-hour intragastric pH, percentage of time pH was ≥ 3, and percentage of time pH was ≥ 4 were determined.

Results—Median pH, percentage of time pH was ≥ 3, and percentage of time pH was ≥ 4 were all significantly higher when food was withheld than when dogs were fed. Famotidine, pantoprazole, and omeprazole significantly suppressed gastric acid secretion, compared with saline solution, as determined on the basis of median 24-hour pH and percentages of time pH was ≥ 3 or ≥ 4. However, ranitidine did not. Omeprazole suspension suppressed gastric acid secretion.

Conclusions and Clinical Relevance—Results suggest that in healthy dogs, famotidine, pantoprazole, and omeprazole significantly suppress gastric acid secretion. Twice daily administration of a suspension of omeprazole, was the only regimen tested that approached the potential therapeutic efficacy for acidrelated disease when assessed by criteria used for human patients. (Am J Vet Res 2005;66:425–431)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the role of veterinary team effectiveness regarding job satisfaction and burnout in companion animal veterinary practice.

Design—Cross-sectional observational study.

Sample—48 companion animal veterinary health-care teams.

Procedures—274 team members participated in an online survey. Overall job satisfaction was evaluated with a 1-item measure, and the 3 dimensions of burnout (exhaustion, cynicism, and professional efficacy) were measured with the Maslach Burnout Inventory-General Survey. Team effectiveness was assessed with a survey developed for this study. Demographic and team effectiveness factors (coordinated team environment, toxic team environment, team engagement, and individual engagement) associated with job satisfaction and burnout were evaluated.

Results—Overall mean job satisfaction score was 5.46 of 7 (median, 6.00); veterinary technicians and kennel attendants had the lowest scores. According to the Maslach survey results, 22.4% of participants were in the high-risk category for exhaustion, 23.2% were in the high-risk category for cynicism, and 9.3% were in the high-risk category for professional efficacy. A coordinated team environment was associated with increased professional efficacy and decreased cynicism. A toxic team environment was negatively associated with job satisfaction and positively associated with exhaustion and cynicism. Individual engagement was positively associated with job satisfaction and professional efficacy and negatively associated with exhaustion and cynicism.

Conclusions and Clinical Relevance—Results suggested the effectiveness of a veterinary team can significantly influence individual team members’ job satisfaction and burnout. Practices should pay specific attention to the effectiveness with which their veterinary team operates.

Full access
in Journal of the American Veterinary Medical Association

Objective

To assess the efficacy of clomipramine for treatment of canine compulsive disorder (CCD).

Design

Randomized, placebo-controlled, double-blind, balanced AB-BA crossover clinical study

Animals

51 dogs with CCD.

Procedures

Dogs were given clomipramine (3 mg/kg [1.3 mg/lb] of body weight, PO, q 12 h) for 4 weeks and placebo for 4 weeks. At the end of each treatment each owner rated the severity of their dog's behavior, using 2 validated rating scales. Statistical analysis was made by ordinal regression. Compliance, adverse effects, and the effectiveness of masking were also assessed. Each dog's behavior was reevaluated 1 to 2 years after completing the study.

Results

Behaviors included spinning (n = 17) and self-mutilation by licking (acral lick dermatitis, 12). Both rating scales demonstrated a treatment effect. Compliance was satisfactory, and masking was effective. Sedation and reduced appetite were reported more commonly when dogs were given clomipramine than when they were given placebo. Forty-five dogs available for follow-up evaluation still had their behaviors; 6 dogs were lost to follow-up evaluation.

Clinical Implications

Results suggest that clomipramine was effective in dogs with CCD and was not associated with serious adverse effects. However, treatment for 4 weeks was not curative. Behavior modification is likely to be necessary to manage CCD. (J Am Vet Med Assoc 1998;213:1760–1766)

Free access
in Journal of the American Veterinary Medical Association