Evaluation of the presence of selected viral and bacterial nucleic acids in pericardial samples from dogs with or without idiopathic pericardial effusion

Many viruses have been identified in pericardial fluid and in tissue samples from humans with pericarditis by means of molecular diagnostics. In canine idiopathic pericardial effusion there is as yet no conclusive evidence to support the involvement of an infectious agent. This study was designed to investigate a possible relationship between idiopathic pericardial effusion in dogs and viruses most commonly encountered in humans affected with viral pericarditis. Coxsackievirus B3 RNA, influenza virus type A RNA, human adenovirus type 2 DNA, human cytomegalovirus DNA, and parvovirus B19 DNA were investigated using PCR on pericardial effusion samples and pericardial tissue specimens collected from 14 dogs with idiopathic pericardial effusion. PCR was also used to test for two bacteria, Borrelia burgdorferi and Chlamydia pneumoniae. The same microorganisms were also looked for in pericardial effusions or pericardial washes from 10 dogs with neoplastic pericardial effusion, and in samples collected from 10 dogs which died of a non-cardiac disease. One pericardial effusion sample from a dog with the idiopathic form of the disease tested positive for influenza virus type A and sequencing of the amplicon confirmed the PCR result. In another dog from the same group a cytomegalovirus was detected by PCR in the effusion, but sequencing showed this to be a false-positive result. The genomes of the microorganisms investigated were not detected in neoplastic effusions or pericardial washes. The results indicate that viral and bacterial DNA/RNA of relevance for human pericarditis is rare in pericardial samples from dogs with idiopathic pericardial effusion. The finding of influenza type A viral RNA in pericardial fluid from one dog with the idiopathic form of the disease warrants further investigation.     

Cardiac troponins I and T in dogs with pericardial effusion

Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) are sensitive and specific markers for myocardial ischemia and necrosis. Dogs with pericardial effusion frequently have myocardial ischemia and necrosis, and these changes are more severe in dogs with hemangiosarcoma (HSA). We investigated the utility of using serum cTnI and cTnT concentrations to identify the idiopathic pericardial effusion from that associated with HSA. Blood samples for measurement of cTnI and cTnT concentrations were collected before pericardiocentesis in 37 dogs with pericardial effusion. Eighteen dogs had a mass consistent with HSA, 6 dogs had idiopathic pericardial effusion, 1 dog had mesothelioma, and 1 dog had a heart base tumor. No final diagnosis was achieved for 11 dogs. Dogs with pericardial effusion had significantly higher serum concentrations of cTnI (P < .001) but not cTnT (P = .16) than did normal dogs. Dogs with HSA had significantly higher concentrations of cTnI (2.77 ng/dL; range: 0.09-47.18 ng/dL) than did dogs with idiopathic pericardial effusion (0.05 ng/dL; range: 0.03-0.09 ng/dL) (P < .001). There was no difference in the concentration of cTnT between dogs with HSA and those with idiopathic pericardial effusion (P = .08). Measurement of cTnI may be useful in helping to distinguish between idiopathic pericardial effusion and pericardial effusion caused by HSA.     

Idiopathic, aseptic, effusive, fibrinous, nonconstrictive pericarditis with tamponade in a standardbred filly.

A Standardbred filly was admitted for evaluation of pleuritis and pneumonia. Heart rate was 80 to 120 beats/min, and the pulse was barely palpable. Thoracic and abdominal ultrasonography and echocardiography revealed substantial pericardial effusion with cardiac tamponade, fibrinous pericarditis, pleural effusion, and ascites. Initial electrocardiography revealed normal sinus rhythm with decreased amplitude of the QRS complexes consistent with pericardial effusion. Following thoracentesis, echocardiogram-guided pericardiocentesis was performed. Bacterial culture yielded no growth from any of the fluids, and bacteria were not seen on cytologic examination. Initial treatment included broad-spectrum antibiotic treatments, IV fluid therapy, and anti-inflammatory agent administration. On the basis of negative culture results, an immune-mediated cause was considered, and dexamethasone was instituted in a decreasing dosage regimen. Pericardial effusion, ventral edema, and ascites began to resolve within 3 days after beginning dexamethasone treatment. Thirty days following discharge, the filly was reexamined, and at that time, the prognosis for athletic performance was considered good so the horse was returned to race training. The final diagnosis in this case was idiopathic, effusive, nonconstrictive pericarditis with tamponade. Early identification, clinical understanding, and application of knowledge of the pathophysiologic mechanisms of pericarditis in horses, combined with use of diagnostic aids such as ultrasonography and aggressive therapy consisting of effusion drainage, pericardial lavage, antibiotics that penetrate the pericardium, and corticosteroids when indicated are critical for a successful outcome in horses with pericarditis.     

Biochemical analysis of pericardial fluid and whole blood in dogs with pericardial effusion

Studies evaluating pericardial fluid analysis in dogs to determine the etiology of pericardial effusions have yielded conflicting results. The purpose of this prospective study was to compare acid-base status, electrolyte concentrations, glucose, and lactate of pericardial fluid to peripheral blood from dogs with pericardial effusion and to compare these variables between dogs with neoplastic and nonneoplastic pericardial effusion. Acid-base status, electrolyte concentrations, glucose, hematocrit, urea nitrogen, and lactate concentrations were evaluated in peripheral blood samples and in pericardial effusion samples of 41 client-owned dogs with pericardial effusion. Common abnormal findings in the peripheral blood of dogs with pericardial effusion included hyperlactatemia (n = 38 [of 41]; 93%), hyponatremia (n = 25/41; 61%), hyperglycemia (n = 13/41; 32%), and hypermagnesemia (n = 13/41; 32%). Bicarbonate, sodium, ionized calcium, glucose, and hematocrit were all significantly lower in the pericardial fluid compared with peripheral blood, whereas lactate, chloride, and PCO2 were significantly higher in the pericardial fluid. When comparing the concentrations of variables in the pericardial fluid of dogs with neoplasia (n = 28) to those without neoplasia (n = 13), pH, bicarbonate, and chloride were significantly lower in dogs with neoplasia, whereas lactate, hematocrit, and urea nitrogen were significantly higher in the pericardial fluid of dogs with neoplasia. The difference between peripheral and pericardial glucose concentrations was significantly larger in dogs with neoplasia than in dogs without neoplasia. Although differences between variables in dogs with neoplastic and nonneoplastic pericardial effusion were documented, clinical relevance is likely limited by the degree of overlap between the 2 groups.     

Anaerobic bacterial pericardial effusion in a cat

A 9-year-old male cat was presented for evaluation of chronic weight loss and was subsequently diagnosed with pericardial effusion. The effusion was quantified as a septic exudate caused by the anaerobic bacterium Peptostreptococcus. Antibiotic therapy resulted in complete resolution of the pericardial effusion. As Peptostreptococcus is a common oral bacterium and the cat had a previous dental procedure, it is speculated that the pericardial effusion was secondary to bacteraemia from the dental procedure.     

Idiopathic aseptic pericardial effusion with cardiac tamponade in a horse

This report describes the successful treatment of pericardial effusion and cardiac tamponade in a 10‐year‐old Hanoverian gelding. Pericarditis and pericardial effusion are uncommon conditions in horses. Although many potential causes for the effusion have been described most cases are classified as idiopathic. The most valuable diagnostic procedure for the detection of pericardial effusion is echocardiography. Pericardiocentesis and drainage of the fluid were carried out in this case. At one year follow‐up there were no clinical signs of recurrence and the horse has returned to his previous level of athletic performance.     

Disease association and clinical assessment of feline pericardial effusion

Records were reviewed from 83 cases to determine the main causes and clinical significance of feline pericardial effusion. The most common causes included hypertrophic cardiomyopathy with congestive heart failure, neoplasia, and systemic infection. Most cases had concurrent or secondary pleural effusion or pulmonary edema, with clinical signs of respiratory disease. However, several cases appeared to be affected solely by pericardial effusion rather than pulmonary pathology. Feline pericardial effusion remains an infrequent diagnosis, but its clinical relevance and association with severe cardiac and extracardiac disease warrant diagnostic evaluation.     

Pericardial effusion in a dog with rhabdomyosarcoma in the right ventricular wall

A seven-year-old male labrador retriever presented in right heart failure with weak femoral pulses, and pleural, abdominal and mild pericardial effusion. No diagnosis could be established initially. Two days later, the dog developed severe pericardial effusion causing cardiac tamponade. A tumour in the right ventricular wall was visualised on ultrasonographic examination. An exploratory thoracotomy was performed and biopsies of the mass submitted for histopathological examination. A diagnosis of rhabdomyosarcoma arising from the myocardium was established. Cardiac rhabdomyosarcoma has been reported in only two dogs. Neither report was associated with pericardial effusion.     

Pericardial effusion and cardiac tamponade in a cat with extranodal lymphoma

A five-year-old domestic longhaired cat was evaluated for a seven-day history of worsening respiratory distress. Serum analysis for feline leukaemia virus antigen was positive. Pleural effusion was detected on thoracic radiographs and echocardiography revealed a pericardial effusion and cardiac tamponade. Cytological evaluation of the pleural and pericardial effusions showed lymphoblastic cells indicative of disseminated lymphoma. Following thoracocentesis and pericardiocentesis, the cat was treated for lymphoma using the University of Wisconsin-Madison chemotherapy protocol. The cat was sent home after three days and, at the time of writing (six months after initial presentation), was still symptom free. To the authors' knowledge, this is the first report confirming pericardial effusion and cardiac tamponade in the cat as a direct result of an extranodal lymphoma with cytological evidence of neoplastic cells in the pericardial fluid.     

Pericardial effusion and cardiac tamponade caused by intrapericardial granulation tissue in a dog

Objective – To describe and report successful surgical management of pericardial effusion and cardiac tamponade in a dog caused by intrapericardial granulation tissue.
Case Summary – An 8-month-old, intact male, Greater Swiss Mountain Dog was referred for cardiac evaluation following 2 weeks of progressive lethargy, abdominal distention, and difficulty breathing. On the day of presentation, the dog had an episode of acute collapse. A 14-cm multilocular pericardial cystic lesion causing collapse of the right atrial free wall and resulting in pericardial tamponade was observed on echocardiogram. After the dog subsequently experienced two acute episodes of pericardial effusion, a subtotal pericardectomy was performed and clinical signs resolved. The histopathologic diagnosis of the mass was inflammation and granulation tissue, likely caused by a resolving hematoma or abscess.
New or Unique Information Provided – This is the first report of intrapericardial granulation tissue as the cause of pericardial effusion and cardiac tamponade.     

Successful therapy of coumatetralyl rodenticide induced pericardial effusion with pericardiocentesis in a dog

A 5-year-old, intact male, golden retriever was presented with an acute onset of lethargy and respiratory distress. The dog was diagnosed as having rodenticide intoxication with pericardial effusion. Pericardiocentesis was successfully performed and was followed with a blood transfusion. This case suggests that rodenticide intoxication might cause pericardial effusion in dogs.     

Idiopathic or mesothelioma-related pericardial effusion: clinical findings and survival in 17 dogs studied retrospectively

This retrospective study compares the clinical signs and diagnostic findings of 17 canine patients with histopathological diagnoses of idiopathic pericardial effusion (IPE) or pericardial mesothelioma (MS) in order to identify differences in clinical findings or survival times that might aid in premortem differentiation of these disease conditions. Based on this series of cases, clinical signs, physical examination findings and results of non-invasive diagnostic testing are insufficient to differentiate MS from IPE with confidence unless a discrete pericardial or intrapericardial mass can be identified. Surgical biopsy may be misleading if large amounts of highly reactive and invasive mesothelial cells are seen. Recurrence of significant amounts of pleural effusion within 120 days of pericardiectomy may increase the likelihood that MS is the cause of pericardial effusion in cases in which other causes have been excluded. Survival longer than 120 days postpericardiectomy without chemotherapeutic intervention is associated with a decreased probability of the condition being MS.     

Septic fibrinous pericarditis in a cocker spaniel

A four-year-old cocker spaniel presented with cardiac tamponade due to a pericardial effusion, in addition to pyrexia and peripheral neutrophilia and a recent history of chest trauma. Cytological examination of the pericardial effusion revealed a predominant neutrophilia. The echocardiographic findings were of numerous hyperechoic densities in the pericardial space, due to fibrin, with concurrent thickening and distortion of the pericardium. Postmortem examination, including microbiology, revealed the presence of organising septic fibrinous pericarditis associated with a mixed infection of Streptococcus canis, Citrobacter species, Pseudomonas species and alpha-haemolytic streptococci.     

Thoracoscopic partial pericardiectomy in 13 dogs

Thirteen dogs with cardiac tamponade resulting from pericardial effusion were prospectively evaluated to determine feasibility and outcome of thoracoscopic partial pericardiectomy. A lateral thoracoscopic approach allowed adequate exposure to remove a 4- to 5-cm-diameter section of pericardium in all dogs. Complete resolution of cardiac tamponade occurred in all dogs for which there was follow-up (11 dogs). Ten of 13 dogs (76.9%) had neoplastic pericardial effusion. One of these dogs remains alive at 220 days postoperatively and is asymptomatic. The mean survival of the remaining 9 patents with neoplastic effusion was 128 days (range, 14-544 days; median, 38 days). Three of 13 patients (23.1%) had idiopathic pericardial effusion. Two of these dogs remain alive at 585 and 1,250 days postoperatively. One dog with idiopathic pericardial effusion developed cardiomyopathy and was euthanized 18 days after the procedure. Results indicate that the procedure was technically successful in all dogs. No anesthetic complications occurred. Procedural complications included phrenic nerve transection (1 dog), lung laceration (1 dog), and moderate intraoperative bleeding (1 dog). No adverse clinical manifestations of the complications were apparent. We conclude that thoracoscopic partial pericardiectomy is technically feasible and offers several advantages over conventional open thoracic surgical pericardiectomy.     

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.     

Septic pericarditis, aortic endarteritis, and osteomyelitis in a dog

A 7-year-old, female spayed rottweiler was referred with a history of an acute onset of collapse attributable to cardiac tamponade. Thoracic radiographs revealed an enlarged cardiac silhouette compatible with pericardial effusion, sternal osteomyelitis, and an unusual mineralized lesion determined later to be within the aortic wall. The pericardial effusion was a septic exudate secondary to infection with Staphylococcus species and hemorrhage into the pericardium through a mineralized aortic lesion. The case demonstrates the importance of complete evaluation of thoracic radiographs in a patient with cardiac disease and the potential value of cytopathological evaluation of pericardial fluid.     

DIAGNOSTIC PNEUMOPERICARDIOGRAPHY IN DOGS WITH SPONTANEOUS PERICARDIAL EFFUSION

To evaluate the diagnostic accuracy of pneumopericardiography, diagnostic pneumopericardiograms from 39 dogs with spontaneous pericardial effusion of various etiologies were reviewed. Diagnoses were confirmed by surgical biopsy, necropsy, or follow-up evaluation. Thirty-two of 39 studies (82%) were considered diagnostic. There were one false-positive and six false-negative studies. Fifteen of 16 studies (94%) in dogs with idiopathic sanguinous pericardial effusion were negative (i.e., similar to those in normal dogs). Seven of 12 right atrial hemangiosarcomas (58%), six of six heartbase neoplasms (100%), and two of two pericardial cysts (100%) were outlined. Studies in two cases of infective pericarditis revealed abnormal findings, while a negative study was obtained in one patient with pericardial mesothelioma. Lateral positions were most valuable in idiopathic effusions and for outlining heartbase neoplasms. The left lateral recumbent position was particularly important for outlining hemangiosarcomas. Pericardial cysts were profiled best in ventral or dorsal recumbent positions. This study documents the high diagnostic potential of technically adequate pneumopericardiograms in the etiologic diagnosis of pericardial effusion in the dog.     

Diagnostic Yield of Cytologic Analysis of Pericardial Effusion in Dogs

Background

Pericardial effusion cytology is believed by many to be of limited value, yet few studies have evaluated its diagnostic utility.

Objectives

To determine the diagnostic utility of cytologic analysis of pericardial effusion in dogs and to determine if consideration of additional data could improve the diagnostic yield.

Animals

Two hundred and fifty‐nine dogs with cytologic analysis of pericardial effusion performed between April 1990 and June 2012.

Methods

Electronic medical records from a university teaching hospital were retrospectively reviewed; signalment, complete blood count, serum biochemistry, cytologic analysis of pericardial effusion, and echocardiographic data were recorded. Cytology was classified as diagnostic (infectious or neoplastic) or nondiagnostic (hemorrhagic or other) and groups were compared with multiple Student''s t‐tests.

Results

Cytology was grouped as nondiagnostic (92.3%) or diagnostic (7.7%) and characterized as hemorrhagic (90%), neoplastic (4.6%), infectious (3.1%), or other (2.3%). Overall cytologic analysis of pericardial effusion diagnostic utility was 7.7% and increased to 20.3% if the effusion hematocrit (HCT) <10%; echocardiographic evidence of a mass did not result in a significant increase in the diagnostic utility.

Conclusions and Clinical Importance

The diagnostic utility of cytologic analysis of canine pericardial effusion is variable depending on the underlying etiology. In this group of dogs, the diagnostic yield of cytologic analysis was greater for pericardial effusion samples in which the HCT was less than 10%.     

Idiopathic hemorrhagic pericardial effusion with organized thrombi in a dog

A dog was examined because of cardiac tamponade secondary to pericardial effusion. Masses adjacent to the right atrial and ventricular walls were revealed by echocardiography. Pericardectomy and biopsies of the masses established the diagnosis of idiopathic hemorrhagic pericardial effusion with organized thrombi. The dog was healthy 3 months after surgery. These organized thrombi mimicked cardiac neoplasia echocardiographically, and such a possibility should be included in the list of differential diagnoses of cardiac masses.     

Pericardial effusion in a cat with feline infectious peritonitis

This case report describes the disease progression of a male cat with pericardial effusion. Clinical signs (dyspnea, lethargy, and weakness) started very acutely. The initial laboratory profile showed only an increase in alanine aminotransferase enzyme activity. Diagnostic imaging revealed pericardial effusion. Effusion analysis showed a Rivalta-positive, modified transudate. Detection of feline coronavirus antigen in macrophages was negative. General condition and laboratory parameters dramatically worsened within seven days. Therefore, the owners decided to euthanize the cat. Even if effusion variables are macroscopically and microscopically suspicious for FIP, a definitive diagnosis of FIP could only be made by histology (including immunhistochemical staining).