Comparison of pharmacodynamic variables following oral versus transdermal administration of atenolol to healthy cats.

OBJECTIVE: To describe the disposition of and pharmacodynamic response to atenolol when administered as a novel transdermal gel formulation to healthy cats. ANIMALS: 7 healthy neutered male client-owned cats. PROCEDURES: Atenolol was administered either orally as a quarter of a 25-mg tablet or as an equal dose by transdermal gel. Following 1 week of treatment, an ECG and blood pressure measurements were performed and blood samples were collected for determination of plasma atenolol concentration at 2 and 12 hours after administration. RESULTS: 2 hours after oral administration, 6 of 7 cats reached therapeutic plasma atenolol concentrations with a mean peak concentration of 579 +/- 212 ng/mL. Two hours following transdermal administration, only 2 of 7 cats reached therapeutic plasma atenolol concentrations with a mean peak concentration of 177 +/- 123 ng/mL. The difference in concentration between treatments was significant. Trough plasma atenolol concentrations of 258 +/- 142 ng/mL and 62.4 +/- 17 ng/mL were achieved 12 hours after oral and transdermal administration, respectively. A negative correlation was found between heart rate and plasma atenolol concentration. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of atenolol at a median dose of 1.1 mg/kg every 12 hours (range, 0.8 to 1.5 mg/kg) in cats induced effective plasma concentrations at 2 hours after treatment in most cats. Transdermal administration provided lower and inconsistent plasma atenolol concentrations. Further studies are needed to find an effective formulation and dosing scheme for transdermal administration of atenolol.

Cardiac lymphoma and pericardial effusion in dogs: 12 cases (1994-2004).

OBJECTIVE: To determine clinical characteristics and clinicopathologic findings, including results of pericardial fluid analysis, and determine the outcome associated with pericardial effusion caused by cardiac lymphoma in dogs. DESIGN: Retrospective case series. ANIMALS: 12 dogs. PROCEDURE: Medical records of affected dogs were reviewed for echocardiographic findings, radiographic findings, results of pericardial fluid analysis, clinicopathologic findings, treatment protocols, and outcomes. RESULTS: Pericardial effusion was detected by echocardiography in all 12 dogs, and lymphoma was detected by cytologic examination of the effusion (11/12 dogs) or histologic examination of pericardium (3/12). Large-breed dogs were overrepresented; median weight was 40.5 kg (89.1 lb). Most hematologic and biochemical changes were mild and non-specific. Survival time for dogs treated with combination chemotherapeutic agents was 157 days and for dogs that did not receive chemotherapy survival time was 22 days. This difference was not significant, but several dogs had long-term survival. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac lymphoma is an uncommon cause of pericardial effusion, and results suggest that cardiac lymphoma does not always warrant the poor prognosis of other stage V, substage b lymphomas.

Auscultatory, echocardiographic, biochemical, nutritional, and environmental characteristics of mitral valve disease in Norfolk terriers.

OBJECTIVES: In order to more fully understand degenerative mitral valve disease (DMVD) in the Norfolk terrier, we sought to characterize findings from the physical and echocardiographic examination; biochemical, biomarker, and nutritional profiles; and select environmental variables from a cohort of apparently healthy Norfolk terriers. ANIMALS, MATERIALS AND METHODS: Overtly healthy Norfolk terriers ≥ 6 yrs old were recruited by 3 different veterinary hospitals and underwent historical, physical, electrocardiographic (ECG), and 2D/color-flow Doppler echocardiographic examinations. Anterior mitral valve leaflet length, maximal thickness, area, and degree of prolapse were measured or calculated from two-dimensional images. Blood samples were obtained for serum biochemistry, serum serotonin, plasma NT-proBNP, amino acid profile, C-reactive protein, and cardiac troponin I. RESULTS: Of the 48 dogs entered into the study, 23 (48%) had murmurs, 2 (4%) had mid-systolic clicks, 11 (23%) had ECG P pulmonale, and 41 (85%) were deemed to have echocardiographic evidence of DMVD, including 18 Norfolk terriers without a murmur. Seven (15%), 28 (58%), and 13 (27%) dogs were classified as normal (stage 0), International Small Animal Cardiac Health Council (ISACHC) stage 1a, and 1b, respectively. Mean indexed echocardiographic mitral leaflet thickness (P = 0.017), area (P = 0.0002), prolapse (P = 0.0004), and left atrial to aortic diameter (P = 0.01) were significantly different between ISACHC 0, 1a, and 1b. CONCLUSION: DMVD is relatively common in Norfolk terriers and echocardiographic changes consistent with mild DMVD can be seen in dogs without a heart murmur.

Development and evaluation of a questionnaire for assessment of health-related quality of life in cats with cardiac disease.

OBJECTIVE: To develop, validate, and evaluate a questionnaire (Cats' Assessment Tool for Cardiac Health [CATCH] questionnaire) for assessing health-related quality of life in cats with cardiac disease. DESIGN: Prospective study. ANIMALS: 275 cats with cardiac disease. PROCEDURES: The questionnaire was developed on the basis of clinical signs of cardiac disease in cats. A CATCH score was calculated by summing responses to questionnaire items; possible scores ranged from 0 to 80. For questionnaire validation, owners of 75 cats were asked to complete the questionnaire (10 owners completed the questionnaire twice). Disease severity was assessed with the International Small Animal Cardiac Health Council (ISACHC) classification for cardiac disease. Following validation, the final questionnaire was administered to owners of the remaining 200 cats. RESULTS: Internal consistency of the questionnaire was good, and the CATCH score was significantly correlated with ISACHC classification. For owners that completed the questionnaire twice, scores were significantly correlated. During the second phase of the study, the CATCH score ranged from 0 to 74 (median, 7) and was significantly correlated with ISACHC classification. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the CATCH questionnaire is a valid and reliable method for assessing health-related quality of life in cats with cardiac disease. Further research is warranted to test the tool's sensitivity to changes in medical treatment and its potential role as a clinical and research tool.

Use of pimobendan in 170 cats (2006-2010).

HYPOTHESIS/OBJECTIVES: To describe the therapeutic use of pimobendan in cats, describe the patient population to which it was administered, document potential side effects and report the clinical course following administration of pimobendan in conjunction with standard heart failure therapy. It is hypothesized that cats with advanced heart disease including congestive heart failure from a variety of causes will tolerate pimobendan with a minimum of side effects when used in treatment in conjunction with a variety of other medications. ANIMALS, MATERIALS AND METHODS: One hundred and seventy client owned cats with naturally occurring heart disease, one hundred and sixty four of which had congestive heart failure. Medical records were reviewed and owners and referring veterinarians were contacted for follow-up data. Data collected included pimobendan dose, other medications administered concurrently, data collected at physical examination, presence or absence of heart failure, adverse effects, classification of heart disease, echocardiographic data and survival time. The data were analyzed for significance between the initial visit and any follow-up visits. RESULTS: All cats were treated with pimobendan. The median pimobendan dose was 0.24 mg/kg q 12 h. Pimobendan was used in combination with multiple concurrent medications including angiotensin converting enzyme inhibitors, diuretics and anti-thrombotics. Five cats (3.0%) had potential side effects associated with pimobendan. One cat (0.6%) had presumed side effects severe enough to discontinue pimobendan use. Median survival time for 164 cats with congestive heart failure after initiation of pimobendan was 151 days (range 1-870). CONCLUSION: Pimobendan appears to be well tolerated in cats with advanced heart disease when used with a variety of concurrent medications. Randomized controlled studies need to be performed to accurately assess whether it is efficacious for treatment of congestive heart failure in cats.

Peripheral pulmonary artery stenosis in a four-month-old West Highland White Terrier.

A 4-month-old West Highland White Terrier was evaluated for dyspnea. Severe cardiac silhouette enlargement was present radiographically. Severe right ventricular hypertrophy and dilation with a dilated pulmonary trunk and a stenosis of the right pulmonary artery were diagnosed via echocardiography. Additional areas of peripheral pulmonary artery stenosis were diagnosed with nonselective computed tomography (CT) angiography and selective fluoroscopic angiography. Balloon dilation therapy was unsuccessful and the imaging findings were confirmed at necropsy.

Presumptive primary cardiac lymphoma in a cat causing pericardial effusion.

We report a case of primary cardiac lymphoma in a cat, causing pericardial effusion. A 13-year-old castrated male Himalayan cat was evaluated for chronic weight loss and radiographic finding of cardiomegaly. Pericardial effusion and a heart mass were detected via echocardiography. Pericardiocentesis and ultrasound-guided fine needle aspirate of the heart mass were performed under sedation. Antemortem diagnosis of cardiac lymphoma was made based on cytology of pericardial fluid. Based on physical examination, laboratory tests and abdominal radiographs, primary cardiac lymphoma was established as the presumptive clinical diagnosis. Treatment with chemotherapeutic agents was initiated.