Search Results

You are looking at 1 - 8 of 8 items for

  • Author or Editor: M. Amanda Marks x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Objective—To determine the effect of protein binding on the pharmacokinetics and distribution from plasma to interstitial fluid (ISF) of cephalexin and cefpodoxime proxetil in dogs.

Animals—6 healthy dogs.

Procedures—In a crossover study design, 25 mg of cephalexin/kg or 9.6 mg of cefpodoxime/kg was administered orally. Blood samples were collected before (time 0) and 0.33, 0.66, 1, 2, 3, 4, 6, 8, 10, 12, 16, and 24 hours after treatment. An ultrafiltration device was used in vivo to collect ISF at 0, 2, 4, 6, 8, 10, 12, 16, and 24 hours. Plasma and ISF concentrations were analyzed with high-pressure liquid chromatography. Plasma protein binding was measured by use of a microcentrifugation technique.

Results—Mean plasma protein binding for cefpodoxime and cephalexin was 82.6% and 20.8%, respectively. Mean ± SD values for cephalexin in plasma were determined for peak plasma concentration (Cmax, 31.5 ± 11.5 μg/mL), area under the time-concentration curve (AUC, 155.6 ± 29.5 μg•h/mL), and terminal half-life (T½, 4.7 ± 1.2 hours); corresponding values in ISF were 16.3 ± 5.8 μg/mL, 878 ± 21.0 μg•h/mL, and 3.2 ± 0.6 hours, respectively. Mean ± SD values for cefpodoxime in plasma were 33.0 ± 6.9 μg/mL (Cmax), 282.8 ± 44.0 μg•h/mL (AUC), and 5.7 ± 0.9 hours (T1/2); corresponding values in ISF were 4.3 ± 2.0 μg/mL, 575 ± 174 μg•h/mL, and 10.4 ± 3.3 hours, respectively.

Conclusions and Clinical Relevance—Tissue concentration of protein-unbound cefpodoxime was similar to that of the protein-unbound plasma concentration. Cefpodoxime remained in tissues longer than did cephalexin.

Full access
in American Journal of Veterinary Research

Summary

A commercial cryptococcal antigen latex agglutination test was used to evaluate sera from 20 cats with cryptococcosis and 184 cats without cryptococcosis. Cryptococcal antigen was detected in the sera from 19 of 20 cats with cryptococcosis. Antigen was not detected in sera from any of the cats without cryptococcosis. The test had sensitivity of 95% and specificity of 100%.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate early medical and behavioral effects of deployment to the World Trade Center, Fresh Kills Landfill, or the Pentagon on responding search-and-rescue (SAR) dogs.

Design—Prospective double cohort study.

Animals—The first cohort included SAR dogs responding to the September 11, 2001, terrorist attacks (deployed), and the second cohort included SAR dogs trained in a similar manner but not deployed (controls). Enrollment occurred from October 2001 to June 2002.

Procedure—Dogs were examined by their local veterinarians; thoracic radiographs and blood samples were shipped to the University of Pennsylvania for analysis. Handlers completed medical and training histories and a canine behavioral survey.

Results—Deployed dogs were older and had more search experience than control dogs. Serum concentrations of globulin and bilirubin and activity of alkaline phosphatase were significantly higher in deployed dogs, independent of age and training. Despite significant differences in several blood parameters, values for both groups were within reference ranges. No pulmonary abnormalities were detected on radiographs, and no significant differences in behavior or medical history were detected between groups.

Conclusions and Clinical Relevance—Within the first year following the September 11 attacks, there was no evidence that responding dogs developed adverse effects related to their work. Mild but significantly higher serum concentrations of globulin and bilirubin and activity of alkaline phosphatase in deployed dogs suggested higher antigen or toxin exposure. These dogs will be monitored for delayed effects for at least 3 years. (J Am Vet Med Assoc 2004;225:861–867)

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To determine whether directly measured arterial blood pressure differs among anatomic locations and whether arterial blood pressure is influenced by body position.

ANIMALS 33 client-owned dogs undergoing anesthesia.

PROCEDURES Dogs undergoing anesthetic procedures had 20-gauge catheters placed in both the superficial palmar arch and the contralateral dorsal pedal artery (group 1 [n = 20]) or the superficial palmar arch and median sacral artery (group 2 [13]). Dogs were positioned in dorsal recumbency, and mean arterial blood pressure (MAP), systolic arterial blood pressure (SAP), and diastolic arterial blood pressure (DAP) were recorded for both arteries 4 times (2-minute interval between successive measurements). Dogs were positioned in right lateral recumbency, and blood pressure measurements were repeated.

RESULTS Differences were detected between pressures measured at the 2 arterial sites in both groups. This was especially true for SAP measurements in group 1, in which hind limb measurements were a mean of 16.12 mm Hg higher than carpus measurements when dogs were in dorsal recumbency and 14.70 mm Hg higher than carpus measurements when dogs were in lateral recumbency. Also, there was significant dispersion about the mean for all SAP, DAP, and MAP measurements.

CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that arterial blood pressures may be dependent on anatomic location and body position. Because this may affect outcomes of studies conducted to validate indirect blood pressure measurement systems, care must be used when developing future studies or interpreting previous results.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To compare blood pressure measured noninvasively with an oscillometric device that involved use of a novel conical cuff and a traditional cylindrical blood pressure cuff.

ANIMALS 17 adult hound-type dogs.

PROCEDURES Dogs were anesthetized, and a 20-gauge, 1.5-inch catheter was inserted in the median sacral artery. The catheter was attached to a pressure transducer via fluid-filled noncompliant tubing, and direct blood pressure was recorded with a multifunction monitor. A specially fabricated conical cuff was placed on the antebrachium. Four sets of direct and indirect blood pressure measurements were simultaneously collected every 2 minutes. Four sets of measurements were then obtained by use of a cylindrical cuff.

RESULTS The cylindrical cuff met American College of Veterinary Internal Medicine consensus guidelines for validation of indirect blood pressure measurements for mean arterial blood pressure (MAP), systolic arterial blood pressure (SAP), and diastolic arterial blood pressure (DAP). The conical cuff met the consensus guidelines for difference of paired measurements, SD, and percentages of measurements within 10 and 20 mm Hg of the value for the reference method, but it failed a correlation analysis. In addition, although bias for the conical cuff was less than that for the cylindrical cuff for SAP, MAP, and DAP measurements, the limits of agreement for the conical cuff were wider than those for the cylindrical cuff for SAP and MAP measurements.

CONCLUSIONS AND CLINICAL RELEVANCE On the basis of results of this study, use of a conical cuff for oscillometric blood pressure measurement cannot be recommended.

Full access
in American Journal of Veterinary Research

SUMMARY

Indirect immunofluorescent antibody (ifa), latex agglutination (la), and enzyme immunoassay (eia) methods were compared for evaluation of the serum antibody responses of dogs experimentally and naturally exposed to spotted fever-group rickettsiae. Selected sera (obtained on days 1, 42, 53, 124, 145, 236, 255, 264, and 292) were examined from three 8-month-old female Beagles inoculated with Rickettsia rickettsii on days 34 and 250 of the study. A second group of dogs comprised three 8-month-old female Beagles inoculated with R montana on days 34 and 102. Subsequently, these dogs were inoculated with R rickettsii on day 250. Serum samples were obtained from the second group of dogs on days 1, 96, 103, 132, 180, 215, 292, and 494. A third group consisted of 21 naturally exposed dogs, from which sequentially obtained serum samples were available, and which had clinical signs compatible with Rocky Mountain spotted fever. Clinical signs of disease in dogs of the third group resolved after treatment with tetracycline (22 mg/kg of body weight, po, q 8 h) was instituted. At least 2 sequentially obtained serum samples from each dog were tested. In general, the first sample was obtained just prior to treatment and the convalescent serum samples were obtained at weekly or greater intervals thereafter.

For correlation and reactivity data, an ifa test for IgG/IgM (using heavy and light chains-specific conjugate) was used as the reference standard for comparison of results with those of the other tests.

For analyzing sensitivity and specificity data in naturally exposed dogs, the assumption was made that fourfold change in the ifa IgG/IgM titer for R rickettsii or titer ≥ 1,024 identified infected dogs. Threshold titer indicative of specific rickettsial antibody was determined for each test: ifa IgG/IgM, 64; ifa IgM, 8; la, 16; EIA IgG, 64; and EIA IgM, 64. Marked cross-reactivity of sera with R rickettsii, R rhipicephali, and R montana was apparent for the ifa method using these antigens; lesser cross-reactivity was observed for R bellii. Although the ifa test for IgM, using R rickettsii as antigen, had high specificity (88.2%), it had low sensitivity (21.7%), limiting its use as a sole diagnostic test. The la test had a higher sensitivity (58.5%) than did any of the IgM ifa tests. The la test results correlated best with IgM ifa test results, and the closest agreement was obtained when R bellii was used as antigen. Because of its relatively high sensitivity (58.5%) and specificity (83.6%), the la procedure may be a valuable screening test for diagnosis of Rocky Mountain spotted fever in dogs. The IgG and IgM EIA methods had high sensitivity- 90.6 and 83.1%, respectively. The IgM EIA performed by us had low specificity; it detected infection with R montana in inoculated dogs. Comparing results of all test methods in naturally exposed dogs, the IgM EIA results were positive for the greatest number of samples with corresponding negative results by the reference IgG/IgM ifa test. This low specificity may preclude its routine use as a diagnostic test. No single serologic method correctly identified all affected dogs. On the basis of comparison with results obtained for the other serologic procedures and antigen-detection methods in 1 dog, the IgG/IgM ifa test used as a reference test may not have detected some infected dogs. Combination of a test that detects predominantly IgG, with either the la or IgM ifa test, would help to identify most infected dogs.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To characterize mucosal gene expression in dogs with chronic enteropathy (CE).

Animals—18 dogs with CE and 6 healthy control dogs.

Procedures—Small intestinal mucosal biopsy specimens were endoscopically obtained from dogs. Disease severity in dogs with CE was determined via inflammatory bowel index scores and histologic grading of biopsy specimens. Total RNA was extracted from biopsy specimens and microchip array analysis (approx 43,000 probe sets) and quantitative reverse transcriptase PCR assays were performed.

Results—1,875 genes were differentially expressed between dogs with CE and healthy control dogs; 1,582 (85%) genes were downregulated in dogs with CE, including neurotensin, fatty acid–binding protein 6, fatty acid synthase, aldehyde dehydrogenase 1 family member B1, metallothionein, and claudin 8, whereas few genes were upregulated in dogs with CE, including genes encoding products involved in extracellular matrix degradation (matrix metallopeptidases 1, 3, and 13), inflammation (tumor necrosis factor, interleukin-8, peroxisome proliferator–activated receptor γ, and S100 calcium-binding protein G), iron transport (solute carrier family 40 member 1), and immunity (CD96 and carcinoembryonic antigen–related cell adhesion molecule [CEACAM] 18). Dogs with CE and protein-losing enteropathy had the greatest number of differentially expressed genes. Results of quantitative reverse transcriptase PCR assay for select genes were similar to those for microchip array analysis.

Conclusions and Clinical Relevance—Expression of genes encoding products regulating mucosal inflammation was altered in dogs with CE and varied with disease severity.

Impact for Human Medicine—Molecular pathogenesis of CE in dogs may be similar to that in humans with inflammatory bowel disease.

Full access
in American Journal of Veterinary Research

Abstract

Supply chain issues disrupt veterinary care and cause downstream consequences that alter the practice of veterinary medicine. Antimicrobials are just 1 class of pharmaceuticals that have been impacted by supply chain issues over the last couple of years. Since February 2021, 2 sponsors/manufacturers of penicillin products have reported shortages in the active pharmaceutical ingredient. With the release of the 2021 Summary Report on Antimicrobials Sold or Distributed for Use in Food-Producing Animals by the FDA, a key finding was a 19% decrease in penicillin sales and distribution from 2020 to 2021. Herein, we provide our clinicians’ professional perspective regarding how drug shortages, specifically that of penicillin, might contribute to misconstrued patterns in antimicrobial use and what can be done by veterinarians and the FDA to minimize the impact of an antimicrobial drug shortage on animal health and well-being.

Free access
in Journal of the American Veterinary Medical Association