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- Author or Editor: Kenneth R. Harkin x
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Abstract
OBJECTIVE To use variable-number tandem-repeat (VNTR) analysis to determine the infecting serovar and strain for leptospiral DNA isolated from canine urine samples confirmed through PCR testing to contain pathogenic leptospires and to evaluate the sensitivity and specificity of microscopic agglutination testing (MAT) for identifying the infecting serogroup.
DESIGN Diagnostic survey and test evaluation.
SAMPLE Leptospiral DNA isolated from urine samples from 98 dogs confirmed through PCR testing to have pathogenic leptospires in their urine.
PROCEDURES VNTR analysis of DNA isolates was performed to identify the infecting leptospiral serovar and strain by use of primer pairs for the loci 4, 7, 10, and Lb5. Eighteen pathogenic and 2 saprophytic leptospiral serovars were used as reference strains for VNTR analysis. Results of MAT were compared with those of the PCR assay and VNTR analysis to determine the sensitivity and specificity of MAT for diagnosing leptospirosis and identifying the infecting serovar at various reciprocal titers.
RESULTS VNTR analysis identified Leptospira kirschneri serovar Grippotyphosa strain DF as the most common infecting serovar in dogs (78/98 [80%]). Thirteen unique VNTR patterns could not be identified by comparison with the Leptospira reference strains used. The MAT had a maximum sensitivity of 41% and a specificity of 100% for identifying Grippotyphosa as the infecting serogroup.
CONCLUSIONS AND CLINICAL RELEVANCE Findings confirmed the importance of Leptospira serovar Grippotyphosa among dogs in the United States. Serologic testing had poor sensitivity for identifying the infecting serogroup, and conclusions about emerging serogroups should be cautiously interpreted when serologic data are reported.
Abstract
Objective—To evaluate the use of a polymerase chain reaction (PCR) assay on urine samples for diagnosis of leptospirosis in dogs.
Design—Prospective case study.
Animals—132 dogs with clinical signs suggestive of leptospirosis and 13 healthy dogs.
Procedure—PCR testing was performed on urine samples to detect leptospiral DNA; results were compared with results of conventional criteria for the diagnosis of leptospirosis.
Results—Leptospirosis was diagnosed in 8 dogs via established criteria; all these dogs had positive results of PCR assay, including 1 dog with positive results before seroconversion developed. A positive PCR assay result was also obtained in 16 dogs that did not have a confirmed diagnosis of leptospirosis. In the 8 dogs that had a confirmed diagnosis of leptospirosis, serovars pomona (n = 3 dogs), grippotyphosa (2), canicola (2), and bratislava (1) were identified serologically. The remaining 121 dogs all had a diagnosis other than leptospirosis or were healthy. For PCR testing on urine, sensitivity was 100%, specificity was 88.3%, positive predictive value was 33%, and negative predictive value was 100%.
Conclusions and Clinical Relevance—Positive PCR test results prior to seroconversion may have value in establishing an early diagnosis. Positive results in dogs that had signs consistent with leptospirosis despite failing to meet established criteria for leptospirosis raise questions regarding the sensitivity of serologic testing in diagnosis of leptospirosis. Serovars pomona, grippotyphosa, and canicola were most common. (J Am Vet Med Assoc 2003;222:1224–1229)
Abstract
Objective—To describe clinical, laboratory, and surgical findings in dogs with confirmed gallbladder rupture and in which serum total bilirubin concentration was within reference limits.
Design—Retrospective case series.
Animals—5 dogs.
Procedures—Medical records were searched to identify dogs with gallbladder rupture that underwent treatment at the Kansas State University Veterinary Health Center from November 2007 through November 2013. Dogs were included if they had undergone abdominal ultrasonography, serum total bilirubin concentration was ≤ 0.4 mg/dL, and abdominal exploratory surgery confirmed the presence of gallbladder upture.
Results—An exploratory celotomy was performed in all dogs because of ultrasonographic findings of mild to marked abdominal effusion and either an unidentifiable gallbladder (n = 1 dog) or a distended gallbladder with a suspected gallbladder mucocele (4 dogs). Serum total bilirubin concentration was within reference limits (median, 0.2 mg/dL; range, 0.1 to 0.4 mg/dL; reference range, 0.1 to 0.4 mg/dL) in all dogs before surgery. In 1 dog, bile acids concentrations in serum and in peritoneal fluid were compared and the results (48 μmol/L and 1,070 μmol/L, respectively) were supportive of the diagnosis of gallbladder rupture.
Conclusions and Clinical Relevance—Results indicated that even when serum total bilirubin concentration is within reference limits, gallbladder rupture should be considered in dogs with acute signs of abdominal pain when a mucocele is suspected on abdominal imaging and free abdominal fluid is present. Results suggested that a comparison of serum to peritoneal fluid bile acids concentrations may provide additional support for a diagnosis of gallbladder rupture.
Abstract
OBJECTIVE
To determine the sensitivity and specificity of a commercial whole blood real-time PCR assay (RT-PCR) for the diagnosis of histoplasmosis when compared to direct organism identification and/or urine antigen quantification by enzyme immunoassay (UA-EIA). A secondary objective was to compare the sensitivity and specificity of RT-PCR to anti–Histoplasma immunoglobulin G antibody detection by enzyme immunoassay (IgG-EIA) and IgG-EIA to UA-EIA.
ANIMALS
Cats presented to the Kansas State University Veterinary Health Center from February through September of 2023 in which histoplasmosis was diagnosed or suspected.
METHODS
From February through September of 2023, cats were tested by RT-PCR, IgG-EIA, and UA-EIA if histoplasmosis was diagnosed cytologically or was a differential diagnosis for the presenting clinical signs. Cats were excluded if all 3 tests were not submitted or if the diagnosis of histoplasmosis could not be excluded despite a negative UA-EIA result. Cats with cytologically or histologically confirmed histoplasmosis were designated as proven histoplasmosis cases, and cats with a positive UA-EIA result without cytological or histological confirmation were designated as probable histoplasmosis cases.
RESULTS
10 cats were diagnosed with either proven (n = 6) or probable (4) histoplasmosis, and 10 cats were considered true negatives. Whole blood RT-PCR results were negative in all 20 cats (sensitivity, 0%; 95% CI, 0% to 30.85%). The IgG-EIA was 90% sensitive (95% CI, 55.50% to 99.75%) and 70% specific (95% CI, 34.75% to 93.33%). The UA-EIA results were positive in all cats with proven histoplasmosis.
CLINICAL RELEVANCE
This commercial RT-PCR is insensitive when used on whole blood collected in EDTA and should not be used to diagnose feline histoplasmosis. Further studies are required to determine whether alternate RT-PCR protocols for EDTA-collected whole blood could be useful for diagnosing histoplasmosis in cats.
Abstract
Objective—To determine signalment, history, clinical findings, results of autonomic function testing and other antemortem diagnostic tests, and pathologic findings in dogs with dysautonomia.
Design—Retrospective study.
Animals—65 dogs with dysautonomia.
Procedure—Case records of 68 dogs with a diagnosis of dysautonomia were reviewed; inclusion criteria included histologic confirmation of dysautonomia or clinical signs and results of pharmacologic testing consistent with dysautonomia.
Results—65 dogs fulfilled all criteria for dysautonomia. Dogs from rural environments were overrepresented, and cases of dysautonomia were reported for every month, although the highest number of cases was reported in February and March. Vomiting was the most common clinical sign, followed by diarrhea, signs of anorexia and depression, weight loss, and dysuria. The most common physical examination finding was decreased or absent anal tone, followed by absent pupillary light reflexes and elevated nictitating membrane. Results of pharmacologic te sting were consistent with dysautonomia, although no single test was 100% sensitive. Histologic lesions consistent with dysautonomia were found in the autonomic ganglia, brainstem nuclei, and ventral horns of the spinal cord.
Conclusions and Clinical Relevance—Dysautonomia is an endemic disease in Kansas, and a high index of suspicion of the disease can be made by combining clinical signs, physical examination findings, and results of pharmacologic testing. (J Am Vet Med Assoc 2002;220:633–639)
Abstract
Objective—To describe echocardiographic findings in dogs with dysautonomia.
Design—Prospective case series.
Animals—20 dogs with dysautonomia (13 confirmed during necropsy and 7 with results of antemortem testing [tear production, pilocarpine response test, atropine response test, and ID histamine response] supportive of the diagnosis).
Procedures—Dogs with dysautonomia were evaluated by use of echocardiography, and M-mode measurements were obtained on all dogs. A dobutamine response test was performed on 1 dog, starting at a rate of 1 μg/kg/min and doubling the rate every 15 minutes until fractional shortening (FS) increased to > 2 times the baseline value.
Results—Evidence of systolic dysfunction was detected in 17 of 20 dogs with dysautonomia, as determined on the basis of FS (median, 17.9%; range, 4.0% to 31.1%). Left ventricular internal dimension during diastole or left ventricular internal dimension during systole was enlarged in 4 of 20 and 14 of 20 dogs, respectively. Enlargement of the left atrium or aorta was identified in 3 of 15 and 1 of 15 dogs in which it was measured, respectively. Administration of dobutamine at a rate of 4 μg/kg/min resulted in dramatic improvement in FS (increase from 4% to 17%) in the 1 dog tested.
Conclusions and Clinical Relevance—Results suggested that echocardiographic evidence of diminished systolic function was common in dogs with dysautonomia. Whether the diminished function was a result of sympathetic denervation or myocardial hibernation was unclear, although myocardial hibernation was more likely.
Abstract
Objective—To determine serum antinuclear antibody (ANA) titers in dogs with systemic lupus erythematosus (SLE) and in dogs with related clinical and clinicopathologic findings.
Design—Retrospective case series.
Animals—120 dogs.
Procedures—Information that was evaluated included signalment, clinical signs, results of routine laboratory testing, ANA titer, and diagnosis.
Results—The most common clinical signs were arthralgia, myalgia, and stiffness (n = 41 [34.2%]); the most common clinicopathologic abnormality was thrombocytopenia (30 [25%]). Serum ANA titer was < 160 (seronegative) in 89 dogs (74.2%), 160 in 14 dogs (11.7%), 320 in 5dogs (4.2%), and ≥ 640 in 12 dogs (10%). Immune-mediated disease was confirmed in 40 dogs, 18 of which fulfilled the criteria for a definitive or probable diagnosis of SLE. Only 1 of 47 dogs with no major signs compatible with SLE had immune-mediated disease, compared with 26 of 57 dogs with 1 major sign and 13 of 16 dogs with ≥ 2 major signs.
Conclusions and Clinical Relevance—Results suggested that measurement of ANA titer was not a useful diagnostic test in dogs without any major clinical or clinicopathologic abnormalities suggestive of SLE. In contrast, there was a good chance that results of the ANA assay would be positive and that the dog would be found to have immune-mediated disease if at least 2 major signs were evident. Findings suggest that it would be reasonable to limit the use of the ANA assay to those dogs that have at least 1 major sign compatible with a diagnosis of SLE.
