Comparison of presumptive echocardiographic and definitive diagnoses of cardiac tumors in dogs.

BACKGROUND: Echocardiography is used for identification of cardiac tumors and presumptive diagnoses often are made based on the location of identified masses. OBJECTIVES: To determine the accuracy of echocardiographically based presumptive diagnoses of cardiac tumors when compared with clinicopathologic or histopathologic definitive diagnoses. ANIMALS: A total of 24 client-owned dogs having a cardiac mass on echocardiogram that was subsequently definitively diagnosed by cytology or histopathology. METHODS: Retrospective study. A Cardiac Veterinary Database search of animals seen at the University of Tennessee John and Ann Tickle Small Animal Hospital from 2006 to 2012 identified 24 dogs that fit the inclusion criteria. RESULTS: The presumptive diagnosis of chemodectoma, ectopic thyroid carcinoma, or lymphoma in cases with heart base masses was correct in 7/9 cases. The presumptive diagnosis of hemangiosarcoma in cases with right atrial masses was correct in 4/8 cases. Seven cases had an open diagnosis because of the unusual presentation on echocardiogram (ECG); various neoplasms were diagnosed in these animals, but hemangiosarcoma, chemodectoma, ectopic thyroid carcinoma, and lymphoma accounted for 6 of them. Pericardial effusion was seen in 10/24 cases. ECG abnormalities were seen in 8/24 cases. Survival ranged from <1 to >150 days. CONCLUSIONS AND CLINICAL IMPORTANCE: In this retrospective study, the presumptive diagnosis based on echocardiographic tumor location was only moderately accurate. Cardiac tumors that were considered unusual on echocardiogram were nonetheless frequently found to be the common cardiac tumor types seen in dogs.

[Pilot study of echocardiographic studies using color- and pulsed-wave spectral Doppler methods in blue-crowned amazons (Amazona ventralis) and blue-fronted amazons (Amazona a. aestiva)]. / Pilotstudie zu echokardiographischen Untersuchungen mittels Farb- und pulsed-wave-Spektraldoppler an Blaukronenamazonen (Amazona ventralis) und Blaustirnamazonen (Amazona a. aestiva).

Colour-flow and pulsed-wave spectral Doppler echocardiography was performed on 6 healthy, adult Hispaniolan amazon parrots (Amazona ventralis) and 6 blue-fronted amazon parrots (Amazona a. aestiva) to establish normal reference values. Birds were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. An electrocardiogram was recorded continuously and birds were imaged with a micro-phased-array scanner with a frequency of 7.0 MHz. After assessment of cardiac function in 2-D-echocardiography, blood flow across the left and the right atrioventricular valve and across the aortic valve was determined using color-flow and pulsed-wave spectral Doppler echocardiography. Diastolic inflow (mean value +/- standard deviation) into the left ventricle was 0.17 +/- 0.02 m/s (Hispaniolan amazons) and 0.18 +/- 0.03 m/s (Blue fronted amazons). Diastolic inflow into the right ventricle was 0.22 +/- 0.05 m/s (Hispaniolan amazons) and 0.22 +/- 0.04 m/s (Blue fronted amazons). Velocity across the aortic valve was 0.84 +/- 0.07 m/s (Hispaniolan amazons) and 0.83 +/- 0.08 m/s (Blue fronted amazons). Systolic pulmonary flow could not be detected in any of the birds in this study. No significant differences were evident between the two species examined. Results of this study indicate that Doppler echocardiography is a promising technique to determine blood flow in the avian heart. Further studies in other avian species are needed to establish reference values for assessment of cardiac function in diseased birds.

Peritoneal effusion in cats: 65 cases (1981-1997).

OBJECTIVE: To determine signalment, diagnoses, presence of effusions in multiple sites, and outcome in cats with peritoneal effusion. DESIGN: Retrospective case series. ANIMALS: 65 cats. PROCEDURE: Medical records from 1981 to 1997 were reviewed to obtain information on cats with peritoneal effusion identified on physical examination, radiographs, abdominal ultrasonograms, or at necropsy. RESULTS: Conditions most commonly associated with peritoneal effusion in cats, in order of frequency, were cardiovascular disease, neoplasia, hepatic disease, renal disease, feline infectious peritonitis, peritonitis attributable to other causes, and urinary tract trauma. Dilated cardiomyopathy (DCM) was the most common disease associated with peritoneal effusion; however, DCM was diagnosed in most of these cats before taurine deficiency was found to be a primary cause of this form of cardiomyopathy in cats. Neoplasia was the most common cause after 1987. Right-sided congestive heart failure was the most commonly associated disorder in cats < 1 year old, whereas neoplastic disease was more common with increasing age. Most effusions were detected during the initial physical examination and were modified transudates. Peritoneal effusion was commonly accompanied by fluid accumulation elsewhere, particularly pleural effusion. The prognosis for a cat with abdominal effusion in this study was poor (mean survival time, 21 days; range, 1 to 350 days; median, 2.5 days). CLINICAL IMPLICATIONS: The primary differential diagnosis for peritoneal effusion in cats is neoplastic disease in older cats and right-sided heart failure in kittens. Diseases associated with peritoneal effusion generally have poor prognoses.

Short-term hemodynamic evaluation of circumferential mitral annuloplasty for correction of mitral valve regurgitation in dogs.

OBJECTIVE: To determine the short-term hemodynamic effects associated with circumferential mitral annuloplasty (CMA) in dogs with mitral regurgitation. STUDY DESIGN: Prospective experimental study. Animals-Seven healthy adult mongrel dogs. METHODS: Mitral regurgitation was surgically induced, and annular dilation occurred. Echocardiography and cardiac catheterization were used to determine forward ejection fraction (FEF), regurgitant fraction (RF), pulmonary capillary wedge pressure (PCWP), and annular diameter before and immediately after CMA in five dogs. FEF and RF were also evaluated 7 days after annuloplasty. RESULTS: Mean annular diameter and PCWP were significantly reduced immediately after CMA. Significant increases in FEF of 19% and 22% were shown immediately and 7 days after CMA. Significant reductions in RF of 19% and 22% were also shown immediately and 7 days after annuloplasty. CONCLUSIONS: Sustained hemodynamic benefits and a reduction in annular diameter were achieved by CMA in a canine model of mitral regurgitation. CLINICAL IMPLICATIONS: CMA may be a suitable treatment for heart failure because of mitral regurgitation when early signs of cardiovascular decompensation persist despite appropriate medical management.

Magnetic resonance imaging appearance of intracranial hemorrhage secondary to cerebral vascular malformation in a dog.

A 14-year-old dog developed an acute onset of depression, disorientation, left hemiparesis,left hemianopia, left facial hypoesthesia, and a tendency to turn to the right. Based on these findings, a lesion affecting the right forebrain was suspected. Magnetic resonance imaging showed a mass within the right cerebral hemisphere resulting in compression of the right lateral ventricle and shifting the longitudinal fissure to the left. The lesion was hyperintense on T1-weighted images and hyperintense with focal regions of hypointensity on proton density-, and T2-weighted images, consistent with a subacute hemorrhage. At necropsy, there was a hematoma in the parietal portion of the right cerebral hemisphere. The hemorrhage was surrounded by numerous thin-walled veins, most likely a venous malformation. Magnetic resonance imaging of intracranial hemorrhage is reviewed.

Changes in renal function in cats following treatment of hyperthyroidism using 131I.

Changes in renal function of twenty-two cats treated for hyperthyroidism using radioiodine were evaluated. Serum thyroxine (T4), serum creatinine, blood urea nitrogen (BUN) and urine specific gravity were measured before treatment and 6 and 30 days after treatment. Twenty-two cats had pretreatment and 21 cats had 6 day posttreatment measurement of glomerular filtration rate (GFR) using nuclear medicine imaging techniques. There were significant declines in serum T4 at 6 days following treatment, but the changes in GFR, serum creatinine and BUN were not significant. At 30 days following treatment, there were significant increases in BUN and serum creatinine and further significant declines in serum T4. Nine cats were in renal failure prior to treatment and 13 cats were in renal failure 30 days following treatment. Renal failure was defined as BUN greater than 30 mg/dl and/or serum creatinine greater than 1.8 mg/dl with concurrent urine specific gravity less than 1.035. These 13 cats included eight of 9 cats in renal failure prior to treatment and 5 cats not previously in renal failure. Follow up information beyond 30 days following treatment on 9 of these 13 cats indicated that all remained in renal failure. Based on receiver operating curve analysis of pretreatment glomerular filtration rate (GFR) in predicting posttreatment renal failure, a value of 2.25 ml/kg/min as a point of maximum sensitivity (100%) and specificity (78%) was derived. Fifteen of 22 cats had pretreatment GFR measurements of less than 2.25 ml/kg/min. These 15 cats included all 9 cats in renal failure and 5 cats with normal renal clinicopathologic values prior to treatment. At 30 days following treatment, 13 of these 15 cats were in renal failure. The 2 cats not in renal failure had persistently increased serum T4 values. Seven of 22 cats had pretreatment GFR measurements greater than 2.25 ml/kg/min. None of these 7 cats was in renal failure at 30 days following treatment, all cats having normal BUN, serum creatinine, and urine specific gravity values. It was concluded that significant declines in renal function occur after treatment of hyperthyroidism and this decline is clinically important in cats with renal disease. Pretreatment measurement of GFR is valuable in detecting subclinical renal disease and in predicting which cats may have clinically important declines in renal function following treatment.

Effusive-constrictive pericardial disease secondary to osseous metaplasia of the pericardium in a dog.

Osseous metaplasia of the pericardium causing effusive-constrictive pericardial disease has not, to our knowledge, been reported in dogs. Clinical signs of right-sided congestive heart failure prompted examination of the dog of this report. Documented causes of constrictive pericardial disease in dogs include trauma and actinomycotic, mycobacterial, and fungal infections. These causes were ruled out in this dog. Immune-mediated disorders, as have been reported in people, also were considered unlikely on the basis of test results. It was concluded that this dog had idiopathic osseous metaplasia of the pericardium and pleura. Signs of right-sided congestive heart failure resolved after subtotal pericardiectomy was performed.

Long-term and high-dose trials of enzyme replacement therapy in the canine model of mucopolysaccharidosis I.

Enzyme replacement is a potential therapy for mucopolysaccharidosis I (MPS I), a lysosomal storage disorder caused by alpha-L-iduronidase deficiency. Previous work showed improvement in the tissues of MPS I dogs treated intravenously for 3 months with recombinant human alpha-L-iduronidase (25,000 units or approximately 0.1 mg/kg/week). We have now treated an MPS I-affected dog for 13 months to assess the clinical effects of enzyme replacement. The treated dog gained more weight, was more active, and had less joint stiffness than the untreated littermate. Biochemical and histologic studies demonstrated uptake of alpha-L-iduronidase and decreased lysosomal storage in the liver, kidney, spleen, lymph nodes, synovium, adrenals, and lungs. The brain had detectable enzyme activity and decreased glycosaminoglycan storage although histologic improvement was not evident. Cartilage and heart valve did not show any detectable improvement. A fivefold higher dose (approximately 0.5 mg/kg) administered five times over 10 days to two other dogs resulted in higher tissue enzyme activity and similarly decreased glycosaminoglycan storage and excretion. Antibodies to human alpha-L-iduronidase were induced in all treated dogs and may be associated with immune complex deposition and proteinuria. Recombinant canine alpha-L-iduronidase also induced antibody formation to a similar degree. The results support the conclusion that enzyme replacement is a promising therapy for MPS I though immunologic complications may occur.

Altered platelet indices in dogs with hypothyroidism and cats with hyperthyroidism.

Changes in platelet indices (platelet count and platelet size) and PCV associated with thyroid disease were studied in 7 dogs with hypothyroidism and 21 cats with hyperthyroidism that were admitted to the veterinary teaching hospital. Compared with control (euthyroid) dogs, dogs with hypothyroidism had higher platelet count (P = 0.003), smaller platelet size (P = 0.01), and lower PCV (P = 0.02). Comparison of the group of hyperthyroid cats with a group of similarly aged, clinically normal cats with normal thyroxine values indicated that the group of hyperthyroid cats had significantly (P = 0.03) higher mean platelet size than did control cats, but differences were not found in mean platelet count or PCV. Results of this investigation indicate that the changes in platelet size reported in human beings with thyroid endocrinopathies also are found in animals so-affected. Although the pathogenesis of platelet abnormalities in animals with thyroid derangement is unclear and likely is multifactorial, the observed relation between platelet and erythrocyte production in this group of dogs is consistent with reports of an inverse relation between thrombocytopoiesis and erythropoiesis in iatrogenically hyperthyroid mice and in mice exposed to hypoxia.

Evaluation of the calcium channel-blocking agents diltiazem and verapamil for treatment of feline hypertrophic cardiomyopathy.

To determine the efficacy of and clinical response to several pharmacologic agents for treatment of idiopathic hypertrophic cardiomyopathy in cats, 17 symptomatic cats were randomized to treatment with either propranolol, diltiazem, or verapamil. Clinical, laboratory, radiographic, electrocardiographic, and echocardiographic data were obtained before treatment and after 3 and 6 months of chronic oral therapy. Too few of the cats receiving propranolol or verapamil survived long enough to obtain long-term data needed to make statistical comparisons between groups. However, all 12 cats ultimately treated with diltiazem became asymptomatic, and no adverse effects from this drug were noted in any of these cats. Treatment with diltiazem was associated with a significant reduction of pulmonary congestion assessed radiographically (P less than 0.01), and improved ventricular filling based on echocardiographic measurements of left atrial size (P less than 0.05), left ventricular internal diastolic dimension (P less than 0.05), and relaxation time index (P less than 0.001). There was also a drug-related improvement in jugular venous oxygen tension (P less than 0.001) and blood lactate concentration (P less than 0.01) suggesting improved peripheral perfusion in the cats receiving diltiazem. The results indicate that diltiazem provides an effective and apparently safe treatment for the management of feline hypertrophic cardiomyopathy.

Cardiovascular changes after bone marrow transplantation in dogs with mucopolysaccharidosis I.

Five dogs with mucopolysaccharidosis I, 3 of which had been treated with bone marrow transplantation (BMT), were evaluated for 20 months with electrocardiography, thoracic radiography, and M-mode and 2-dimensional echocardiography. Treated and untreated (control) dogs had widened P waves on ECG. Thoracic radiographs remained normal for all dogs throughout the study. Thickening of the mitral valve was observed on echocardiograms of dogs in both groups, but the untreated dogs appeared to have thicker valves. Concentrations of glycosaminoglycans in the mitral valves and myocardium were higher in control dogs than in treated dogs. Markedly large aortic root diameters were observed on echocardiograms in both untreated dogs, but aortic root diameters remained normal in treated dogs. Echocardiography, but not electrocardiography, was useful in monitoring heart enlargement in each dog. Dogs treated with BMT generally had less severe cardiac changes and slower disease progression than control dogs.

Captopril provides sustained hemodynamic benefits in dogs with experimentally induced mitral regurgitation.

Mitral regurgitation was created surgically in 10 dogs. After measurement of baseline hemodynamic parameters on day 2, treatment with captopril (2 mg/kg orally 3 times daily) was begun in five dogs. Five control dogs received no therapy during the study. The hemodynamic parameters were measured again at weeks 6 and 22. In the treated dogs, the forward ejection fraction (FEF) increased slightly and the total peripheral resistance index (TPRI) decreased. In the controls, the FEF decreased and the TPRI increased. Changes in FEF and TPRI were significantly different between the two groups. The change in FEF correlated significantly with the change in TPRI in both groups. Although the most dramatic changes were observed at week 6, the differences persisted throughout the study. Captopril administration resulted in sustained hemodynamic improvement and may, therefore, delay the onset of congestive heart failure in dogs with mitral regurgitation.

Radiotherapy of metastatic seminoma in the dog. Case reports.

Four dogs with metastatic seminoma were treated with cesium 137 teleradiotherapy. Minimum total tumor dose ranged from 17 to 40 gray (Gy) and was usually given through bilateral opposing sublumbar ports in eight to ten fractions, with three fractions given weekly. The tumor regressed in all four dogs. The first dog (case 1) was free of tumor and died of non-tumor related causes at 57 months. The second dog (case 2) was free of tumor but was euthanatized at 37 months for a limb fracture. The third dog (case 3) was euthanatized for undertermined pulmonary disease 43 months after radiotherapy. The fourth dog (case 4) was euthanatized 6 months following radiotherapy because of transitional cell carcinoma and renal failure. No evidence of seminoma was found at necropsy. Radiotherapy was shown to be effective treatment for seminoma with regional metastasis.

Heart failure caused by gossypol poisoning in two dogs.

Two hound-type dogs from the same kennel were admitted in terminal stages of congestive heart failure. An investigation revealed the owner had been feeding the dogs cottonseed meal daily with their kibbled meal. Gossypol toxicosis from feeding this meal caused marked abnormalities in myocardial contractility. Although in severe congestive heart failure, one dog had only minimal dilatation of its heart, as revealed by thoracic radiography. Disseminated intravascular coagulopathy also was diagnosed in this dog. Gossypol is a cumulative toxin; the amount of free gossypol fed was approximately 5.4 to 5.7 mg/kg/day for an unknown duration.