Search Results

You are looking at 21 - 30 of 36 items for

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

Abstract

Objective—To determine electrocardiographic parameters in healthy llamas and alpacas.

Animals—23 llamas and 12 alpacas.

Procedure—Electrocardiography was performed in nonsedated standing llamas and alpacas by use of multiple simultaneous lead recording (bipolar limb, unipolar augmented limb, and unipolar precordial leads).

Results—Common features of ECGs of llamas and alpacas included low voltage of QRS complexes, variable morphology of QRS complexes among camelids, and mean depolarization vectors (mean electrical axes) that were directed dorsocranially and to the right. Durations of the QT interval and ST segment were negatively correlated with heart rate.

Conclusions and Clinical Relevance—ECGs of acceptable quality can be consistently recorded in nonsedated standing llamas and alpacas. Features of ECGs in llamas and alpacas are similar to those of other ruminants. Changes in the morphology of the QRS complexes and mean electrical axis are unlikely to be sensitive indicators of ventricular enlargement in llamas and alpacas. (Am J Vet Res 2004;65:1719–1723)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To identify cardiac tissue genes and gene pathways differentially expressed between dogs with and without dilated cardiomyopathy (DCM).

ANIMALS 8 dogs with and 5 dogs without DCM.

PROCEDURES Following euthanasia, samples of left ventricular myocardium were collected from each dog. Total RNA was extracted from tissue samples, and RNA sequencing was performed on each sample. Samples from dogs with and without DCM were grouped to identify genes that were differentially regulated between the 2 populations. Overrepresentation analysis was performed on upregulated and downregulated gene sets to identify altered molecular pathways in dogs with DCM.

RESULTS Genes involved in cellular energy metabolism, especially metabolism of carbohydrates and fats, were significantly downregulated in dogs with DCM. Expression of cardiac structural proteins was also altered in affected dogs.

CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that RNA sequencing may provide important insights into the pathogenesis of DCM in dogs and highlight pathways that should be explored to identify causative mutations and develop novel therapeutic interventions.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the usefulness of echocardiography in the diagnosis of heartworm disease in cats and to compare this modality with other tests.

Design—Retrospective study.

Animals—43 cats with heartworm infection that had echocardiographic examinations at 2 veterinary teaching hospitals between 1985 and 1997. Twenty-two of these 43 cats also underwent radiography of the thorax and heartworm antibody and heartworm antigen testing.

Procedure—Cats were determined to be infected with Dirofilaria immitis infection on the basis of 1 or more of the following findings: positive modified Knott or antigen test result, echocardiographic evidence of heartworm disease, or confirmation of the disease on postmortem examination. The percentage of echocardiographs in which heartworms were evident was compared with the percentage of radiographs in which pulmonary artery enlargement was evident and results of antigen or antibody tests in cats in which all tests were performed.

Results—Overall, heartworms were detectable by use of echocardiography in 17 of 43 cats, most often in the pulmonary arteries. In the 22 cats in which all tests were performed, antibody test results were positive in 18, antigen test results were positive in 12, and pulmonary artery enlargement was evident radiographically and heartworms were identifiable echocardiographically in 14. Heartworm infection was diagnosed exclusively by use of echocardiography in 5 cats in which the antigen test result was negative.

Conclusions and Clinical Relevance—Although echocardiography was less sensitive than antigen testing, it was a useful adjunctive test in cats that had negative antigen test results in which there was a suspicion of heartworm disease. The pulmonary arteries should be evaluated carefully to increase the likelihood of detection of heartworms echocardiographically. ( J Am Vet Med Assoc2001;218:66–69)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine aortic ejection velocity in healthy adult Boxers with soft ejection murmurs without overt structural evidence of left ventricular outflow tract obstruction and in healthy Boxers without cardiac murmurs.

Design—Retrospective study.

Animals—201 Boxers.

Procedure—Dogs were examined independently by 2 individuals for evidence of a cardiac murmur, and a murmur grade was assigned. Maximal instantaneous (peak) aortic ejection velocity was measured by means of continuous-wave Doppler echocardiography from a subcostal location. Forty-eight dogs were reexamined approximately 1 year later.

Results—A soft (grade 1, 2, or 3) left-basilar ejection murmur was detected in 113 (56%) dogs. Overall median aortic ejection velocity was 1.91 m/s (range, 1.31 to 4.02 m/s). Dogs with murmurs had significantly higher aortic ejection velocities than did those without murmurs (median, 2.11 and 1.72 m/s, respectively). Auscultation of a murmur was 87% sensitive and 66% specific for the identification of aortic ejection velocity > 2.0 m/s. An ejection murmur and aortic ejection velocity > 2.0 m/s were identified in 73 (36%) dogs. For most dogs, observed changes in murmur grade and aortic ejection velocity during a follow-up examination 1 year later were not clinically important.

Conclusions and Clinical Relevance—Results suggested that ejection murmurs were common among healthy adult Boxers and that Boxers with murmurs were likely to have high (> 2.0 m/s) aortic ejection velocities. The cause of the murmurs in these dogs is unknown. (J Am Vet Med Assoc 2003;222:770–774)

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To evaluate the frequency of variants in the pyruvate kinase dehydrogenase 4 (PDK4) and titin (TTN) genes in a group of Doberman Pinschers with dilated cardiomyopathy (DCM) and to determine whether there were unique clinical attributes to each variant.

ANIMALS

48 Doberman Pinschers with DCM.

PROCEDURES

Doberman Pinschers with recently diagnosed DCM were identified, and genomic DNA from each was genotyped with a PCR assay for detection of PDK4 and TTN genetic variants. Dogs were grouped on the basis of whether they had the TTN variant alone, PDK4 variant alone, both variants, or neither variant. Descriptive statistics were compiled for dog age, body weight, and left ventricular dimensions and fractional shortening and for the presence of ventricular and supraventricular arrhythmias and heart failure. Results were compared across groups.

RESULTS

Of the 48 dogs, 28 had the TTN variant alone, 10 had both variants, 6 had neither variant, and 4 had the PDK4 variant alone. The mean age was younger for dogs with the PDK4 variant alone, compared with other dogs. However, the number of dogs with the PDK4 variant alone was very small, and there was an overlap in age across groups. No other meaningful differences were detected across groups, and independent genotype-phenotype relationships were not identified.

CONCLUSIONS AND CLINICAL RELEVANCE

Although findings indicated that the TTN variant was most common, 6 dogs had neither variant, and this fact supported the concept of ≥ 1 other genetic contributor to DCM in Doberman Pinschers. Future studies are warranted to evaluate genotype-phenotype relationships in Doberman Pinschers with DCM.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To evaluate a group of related Rhodesian Ridgebacks with a family history of sudden death for the presence of arrhythmia and to identify possible patterns of disease inheritance among these dogs.

DESIGN Prospective case series and pedigree investigation.

ANIMALS 25 Rhodesian Ridgebacks with shared bloodlines.

PROCEDURES Pedigrees of 4 young dogs (1 female and 3 males; age, 7 to 12 months) that died suddenly were evaluated, and owners of closely related dogs were asked to participate in the study. Dogs were evaluated by 24-hour Holter monitoring, standard ECG, echocardiography, or some combination of these to assess cardiac status. Necropsy reports, if available, were reviewed.

RESULTS 31 close relatives of the 4 deceased dogs were identified. Of 21 dogs available for examination, 8 (2 males and 6 females) had ventricular tachyarrhythmias (90 to 8,700 ventricular premature complexes [VPCs]/24 h). No dogs had clinical signs of cardiac disease reported. Echocardiographic or necropsy evaluation for 7 of 12 dogs deemed affected (ie, with frequent or complex VPCs or sudden death) did not identify structural lesions. Five of 6 screened parents of affected dogs had 0 to 5 VPCs/24 h (all singlets), consistent with a normal reading. Pedigree evaluation suggested an autosomal recessive pattern of inheritance, but autosomal dominant inheritance with incomplete penetrance could not be ruled out.

CONCLUSIONS AND CLINICAL RELEVANCE Holter monitoring of Rhodesian Ridgebacks with a family history of an arrhythmia or sudden death is recommended for early diagnosis of disease. An autosomal recessive pattern of inheritance in the studied dogs was likely, and inbreeding should be strongly discouraged.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the prevalence of ventricular arrhythmias in clinically normal adult Boxers.

Design—Prospective cross-sectional study.

Animals—301 Boxers (181 females and 120 males) > 1 year old with echocardiographically normal systolic function and no history of syncope or congestive heart failure.

Procedures—Physical examination, which included echocardiography, was performed on all dogs. A 24-hour ambulatory ECG was performed on each dog, and results were evaluated to assess ventricular arrhythmias. Statistical evaluation was performed to determine correlations between the total number of ventricular premature complexes (VPCs)/24 h, grade of ventricular arrhythmia, and age of the dogs.

Results—Age of dogs ranged from 1 to 16 years (median, 4 years). Number of VPCs/24 h in each dog ranged from 0 to 62,622 (median, 6 VPCs/24 h). Grade of arrhythmias ranged from 0 to 3 (median, 1). Age was correlated significantly with number of VPCs/24 h (r = 0.43) and with grade of arrhythmia (r = 0.37). Number of VPCs/24 h was significantly correlated with grade of arrhythmia (r = 0.82).

Conclusions and Clinical Relevance—Clinically normal adult Boxers generally had < 91 VPCs/24 h and an arrhythmia grade < 2. Boxers with > 91 VPCs/24 h were uncommon and may have represented dogs with arrhythmogenic right ventricular cardiomyopathy or other disease processes that could have resulted in the development of ventricular arrhythmias.

Full access
in Journal of the American Veterinary Medical Association

Abstract

A potential emerging shortage of veterinary medical educators requires the profession to acknowledge and understand the factors leading to this outcome. Expanding class sizes within existing schools and colleges of veterinary medicine and the expected expansion of new programs seeking AVMA–Council of Education accreditation have heightened the need to address an impending shortage of veterinary medical educators. A solution-oriented approach that accurately projects educator workforce needs and identifies factors contributing to the shortage requires effective collaboration across various partnering organizations to develop innovations in pedagogy and educational delivery methods. The veterinary profession must also identify and reduce disincentives that deter students and post-DVM trainees from pursuing careers in education. Finally, efforts at the state and federal level are critical to advocate for financial support and incentives for expansion of the veterinary medical educator workforce. Through these collective approaches and partnerships, the veterinary medical educator workforce can be strengthened to overcome obstacles for educating the next generation of veterinarians to meet societal needs.

Restricted access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the potential importance of dystrophin, α-sarcoglycan (adhalin), and β-dystroglycan, by use of western blot analysis, in several breeds of dogs with dilated cardiomyopathy.

Sample Population—Myocardial samples obtained from 12 dogs were evaluated, including tissues from 7 dogs affected with dilated cardiomyopathy, 4 control dogs with no identifiable heart disease (positive control), and 1 dog affected with Duchenne muscular dystrophy (negative control for dystrophin). Of the affected dogs, 4 breeds were represented (Doberman Pinscher, Dalmatian, Bullmastiff, and Irish Wolfhound).

Procedure—Western blot analysis was used for evaluation of myocardial samples obtained from dogs with and without dilated cardiomyopathy for the presence of dystrophin and 2 of its associated glycoproteins, α-sarcoglycan and β-dystroglycan.

Results—Detectable differences were not identified between dogs with and without myocardial disease in any of the proteins evaluated.

Conclusions and Clinical Relevance—Abnormalities in dystrophin, α-sarcoglycan, and β-dystroglycan proteins were not associated with the development of dilated cardiomyopathy in the dogs evaluated in this study. In humans, the development of molecular biological techniques has allowed for the identification of specific causes of dilated cardiomyopathy that were once considered to be idiopathic. The use of similar techniques in veterinary medicine may aid in the identification of the cause of idiopathic dilated cardiomyopathy in dogs, and may offer new avenues for therapeutic intervention. ( Am J Vet Res 2001;62:67–71)

Full access
in American Journal of Veterinary Research