Objective—To evaluate the effect of administration of the labeled dosage of pimobendan to dogs with furosemide-induced activation of the renin-angiotensin-aldosterone system (RAAS).
Animals—12 healthy hound-type dogs.
Procedures—Dogs were allocated into 2 groups (6 dogs/group). One group received furosemide (2 mg/kg, PO, q 12 h) for 10 days (days 1 to 10). The second group received a combination of furosemide (2 mg/kg, PO, q 12 h) and pimobendan (0.25 mg/kg, PO, q 12 h) for 10 days (days 1 to 10). To determine the effect of the medications on the RAAS, 2 urine samples/d were obtained for determination of the urinary aldosterone-to-creatinine ratio (A:C) on days 0 (baseline), 5, and 10.
Results—Mean ± SD urinary A:C increased significantly after administration of furosemide (baseline, 0.37 ± 0.14 μg/g; day 5, 0.89 ± 0.23 μg/g) or the combination of furosemide and pimobendan (baseline, 0.36 ± 0.22 μg/g; day 5, 0.88 ± 0.55 μg/g). Mean urinary A:C on day 10 was 0.95 ± 0.63 μg/g for furosemide alone and 0.85 ± 0.21 μg/g for the combination of furosemide and pimobendan.
Conclusions and Clinical Relevance—Furosemide-induced RAAS activation appeared to plateau by day 5. Administration of pimobendan at a standard dosage did not enhance or suppress furosemide-induced RAAS activation. These results in clinically normal dogs suggested that furosemide, administered with or without pimobendan, should be accompanied by RAAS-suppressive treatment.
Objective—To characterize clinical and clinicopathologic
findings, response to treatment, and causes of
systemic hypertension in cats with hypertensive
Animals—69 cats with hypertensive retinopathy.
Procedure—Medical records from cats with systemic
hypertension and hypertensive retinopathy were
Results—Most cats (68.1%) were referred because
of vision loss; retinal detachment, hemorrhage,
edema, and degeneration were common findings.
Cardiac abnormalities were detected in 37 cats, and
neurologic signs were detected in 20 cats.
Hypertension was diagnosed concurrently with chronic
renal failure (n = 22), hyperthyroidism (5), diabetes
mellitus (2), and hyperaldosteronism (1). A clearly
identifiable cause for hypertension was not detected
in 38 cats; 26 of these cats had mild azotemia, and 12
did not have renal abnormalities. Amlodipine
decreased blood pressure in 31 of 32 cats and
improved ocular signs in 18 of 26 cats.
Conclusions and Clinical Relevance—Retinal
lesions, caused predominantly by choroidal injury, are
common in cats with hypertension. Primary hypertension
in cats may be more common than currently
recognized. Hypertension should be considered in
older cats with acute onset of blindness; retinal
edema, hemorrhage, or detachment; cardiac disease;
or neurologic abnormalities. Cats with hypertensioninduced
ocular disease should be evaluated for renal
failure, hyperthyroidism, diabetes mellitus, and cardiac
abnormalities. Blood pressure measurements
and funduscopic evaluations should be performed
routinely in cats at risk for hypertension (preexisting
renal disease, hyperthyroidism, and age > 10 years).
Amlodipine is an effective antihypertensive agent in
cats.(J Am Vet Med Assoc 2000;217:695–702)
OBJECTIVE To determine the accuracy of a point-of-care lung ultrasonography (LUS) protocol designed to diagnose cardiogenic pulmonary edema (CPE) in dyspneic dogs and cats.
DESIGN Diagnostic test evaluation.
ANIMALS 76 dogs and 24 cats evaluated for dyspnea.
PROCEDURES Dogs and cats were evaluated by LUS; B lines were counted at 4 anatomic sites on each hemithorax. A site was scored as positive when > 3 B lines were identified. Animals with ≥ 2 positive sites identified on each hemithorax were considered positive for CPE. Medical records were evaluated to obtain a final diagnosis (reference standard) for calculation of the sensitivity and specificity of LUS and thoracic radiography for the diagnosis of CPE.
RESULTS Dogs and cats with a final diagnosis of CPE had a higher number of positive LUS sites than did those with noncardiac causes of dyspnea. Overall sensitivity and specificity of LUS for the diagnosis of CPE were 84% and 74%, respectively, and these values were similar to those of thoracic radiography (85% and 87%, respectively). Use of LUS generally led to the misdiagnosis of CPE (ie, a false-positive result) in animals with diffuse interstitial or alveolar disease. Interobserver agreement on LUS results was high (κ > 0.85).
CONCLUSIONS AND CLINICAL RELEVANCE LUS was useful for predicting CPE as the cause of dyspnea in dogs and cats, although this technique could not be used to differentiate CPE from other causes of diffuse interstitial or alveolar disease. Point-of-care LUS has promise as a diagnostic tool for dyspneic dogs and cats.
Objective—To determine the usefulness of echocardiography
in the diagnosis of heartworm disease in cats and to compare this modality with other tests.
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)
To compare the use of curvilinear-array (microconvex) and phased-array transducers for ultrasonographic examination of the lungs in dogs.
13 client-owned dogs with left-sided congestive heart failure.
In a prospective methods comparison study, 24 ultrasonographic examinations of the lungs (4 sites/hemithorax) were performed with both curvilinear-array and phased-array transducers at 3 clinical time points. Two observers independently assessed the number of B lines (scored per site and in total), number of sites strongly positive for B lines (ie, those with > 3 B lines/site), and image quality (scored on a 5-point scale). Analyses included assessment of interobserver agreement with κ analysis, comparison of quality scores between transducers with mixed-effects modeling, and investigation of agreement and bias for B-line data and quality scores between transducers with Passing-Bablok regression.
Interobserver agreement for total B-line scores and number of strong-positive sites was excellent (κ > 0.80) for both transducers. There was no evidence of analytic bias for the number of B lines or strong-positive sites between transducers. Interobserver agreement for image quality scores was moderate (κ, 0.498 and 0.517 for the curvilinear-array and phased-array transducers, respectively). Both observers consistently assigned higher-quality scores to curvilinear-array images than to phased-array images.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated both curvilinear-array (microconvex) and phased-array transducers can be used by experienced sonographers to obtain diagnostic ultrasonographic images of the lungs in dogs with acute or resolving left-sided congestive heart failure and suggested the former transducer may be preferred, particularly to aid identification of anatomic landmarks for orientation.
Objective—To characterize risk factors, clinical findings,
usefulness of diagnostic tests, and prognosis in
cats with naturally occurring heartworm infection (HWI).
Animals—50 cats with Dirofilaria immitis infection.
Procedure—Medical records, thoracic radiographs,
and echocardiograms were reviewed and findings
compared with appropriate reference populations.
Results—Findings suggested that male cats were
not predisposed to HWI, domestic shorthair cats
were at increased risk, and indoor housing was only
partially protective. Fewer cases of HWI were identified
in the final quarter of the year, compared with
other periods, and prevalence is not apparently
increasing. Signs of respiratory tract disease were
most common, followed by vomiting. Infection was
diagnosed incidentally in > 25% of cats; conversely,
10% of infected cats died suddenly without other
clinical signs. Serologic tests were most useful for
diagnosis, followed by radiography and echocardiography.
Eosinophilia supported the diagnosis.
Overall median survival time was 1.5 years but
exceeded 4 years in cats surviving beyond the day
Conclusions and Clinical Relevance—Sex does not
appear to be a risk factor for HWI in cats, and indoor
housing provides only incomplete protection. Signs
of respiratory tract disease (dyspnea and cough) are
the strongest indicators of HWI in cats, and some
radiographic evidence of infection is detected in
most cases. Antibody screening for HWI in cats is
efficacious, and antigen testing and echocardiography
are most useful for making a definitive antemortem
diagnosis. (J Am Vet Med Assoc 2000;217:
To characterize lung ultrasonography (LUS) findings in dogs with a primary clinical complaint of cough.
100 client-owned coughing dogs.
A standardized LUS examination was performed for all dogs to quantify the number of B lines and identify subpleural abnormalities at 4 sites on each hemithorax. The final clinical diagnosis (reference standard) was determined by medical record review, and sensitivity and specificity of LUS for the diagnosis of selected causes of cough was determined.
Common underlying causes of cough included dynamic airway collapse (n = 37), cardiogenic pulmonary edema (CPE; 12), and bronchitis (10). Compared with dogs with other causes of cough, dogs with bacterial pneumonia (n = 7) were more likely to have subpleural shred signs, whereas dogs with pulmonary neoplasia (4) were more likely to have subpleural nodule signs. Dogs with CPE had higher total B-line scores and higher numbers of LUS sites strongly positive for B lines (> 3 B lines/site) than other dogs. The LUS criteria of total B-line score ≥ 10 and presence of ≥ 2 sites strongly positive for B lines were each 92% sensitive and 94% specific for CPE diagnosis. Notably, 18% (16/88) of dogs with noncardiac causes of cough had been treated previously with diuretics because of prior CPE misdiagnosis.
CONCLUSIONS AND CLINICAL RELEVANCE
LUS profiles in dogs with cough differed by the underlying cause. In dogs with a clinical history of cough, this imaging modality could be diagnostically useful, particularly to help exclude the possibility of underlying CPE.
To characterize features of myxomatous mitral valve disease (MMVD) in Miniature Schnauzers and Yorkshire Terriers.
69 Miniature Schnauzers and 65 Yorkshire Terriers, each with MMVD.
Medical record data for each dog were collected; the study period was January 2007 through December 2016. If available, radiographic data were evaluated, and a vertebral heart scale score was assigned for each dog. Statistical analysis was performed with Student t and Fisher exact tests.
Compared with Yorkshire Terriers, the prevalence of MMVD was significantly higher in Miniature Schnauzers and affected dogs were significantly younger at the time of diagnosis. Miniature Schnauzers were significantly more likely to have mitral valve prolapse and syncope, compared with Yorkshire Terriers. Yorkshire Terriers were significantly more likely to have coughing and have had previous or current treatment with cardiac medications, compared with Miniature Schnauzers. There was no statistical difference between breeds with regard to abnormally high vertebral heart scale scores or radiographic evidence of congestive heart failure.
CONCLUSIONS AND CLINICAL RELEVANCE
With regard to MMVD, features of the disease among Miniature Schnauzers and Yorkshire Terriers were similar, but there were also a few discernable differences between these 2 breeds and from historical findings for dogs with MMVD of other breeds. Clinical signs at the time of diagnosis differed between the 2 breeds, which may have reflected concurrent breed-specific conditions (sick sinus syndrome or airway disease [eg, tracheal collapse]). Future work should include prospective studies to provide additional information regarding the natural progression of MMVD in these dog breeds.