Long-term survival of 23 dogs with pericardial effusions

Twenty-three dogs with pericardial effusions were identified from case records made between 1992 and 2000. Fourteen of the 23 were diagnosed with idiopathic pericardial effusions, and three of these were treated successfully by one pericardiocentesis. In the remaining 11 cases the pericardial effusion recurred; six cases were managed long-term by either two (three cases), three (two cases), or 11 repeated pericardiocenteses, and the remaining five were treated by pericardiectomy. The median survival time of the six dogs treated by repeated pericardiocentesis was five years and nine days.     

Use of mycophenolate mofetil as a rescue agent in the treatment of severe generalized myasthenia gravis in three dogs

Objective – To describe the use of IV and oral mycophenolate mofetil (MMF) as adjunctive therapy in 3 dogs with severe generalized myasthenia gravis.
Case Series Summary – Three dogs suffering from severe generalized myasthenia gravis as confirmed by acetylcholine antibody titers were treated with MMF as part of their treatment regimens. All 3 dogs had radiographic evidence of megaesophagus and suffered from severe regurgitation. Each dog was initially treated with pyridostigmine and supportive agents. When clinical remission was not achieved, IV MMF was administered to all dogs. Signs of clinical remission were apparent within 48 hours and all dogs were later maintained on oral MMF following resolution of regurgitation.
New or Unique Information Provided – This is the first report of the use of IV MMF as adjunctive treatment in dogs with severe generalized myasthenia gravis. Outcome was favorable in all 3 dogs and no adverse effects were noted from the MMF.     

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.     

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.     

Echocardiographic evaluation of cardiac tamponade in dogs before and after pericardiocentesis: four cases (1984-1986)

The echocardiographic (M-mode and 2-dimensional) features (before and after pericardiocentesis) of 4 dogs with pericardial effusion and clinical evidence of cardiac tamponade were reviewed. M-Mode echocardiography revealed pericardial effusion, with exaggerated swinging motion of the heart and abnormal septal motion in all 4 dogs. In each case, 2-dimensional echocardiography demonstrated right ventricular diastolic free-wall collapse. Three dogs had right atrial diastolic collapse as well. Clinical signs improved, and right ventricular and right atrial diastolic collapse subsided after pericardiocentesis. Two-dimensional echocardiographic features of right atrial and ventricular collapse were used as indicators for determining the presence of cardiac tamponade.     

Therapeutic pericardiocentesis in the dog and cat

Pericardial effusion is a potentially life-threatening problem leading to a rise in the intrapericardial pressure resulting in varying degrees of hemodynamic compromise. Cardiac tamponade occurs when the intrapericardial pressure equals or exceeds right ventricular diastolic filling pressures leading to a decreased cardiac output. In dogs, the most common causes of pericardial effusion that require pericardiocentesis are cardiac neoplasia and idiopathic pericardial effusion (IPE). The incidence of cardiac neoplasia in dogs is low, and it is rare in cats. In dogs, hemangiosarcoma and chemodectoma are the two most common types of cardiac neoplasia. In cats, lymphosarcoma is the most common form of cardiac neoplasia, but they are more likely to develop pericardial effusion secondary to congestive heart failure or feline infectious peritonitis. Common histories include lethargy, dyspnea, anorexia, collapse, and abdominal distension. Pericardiocentesis is used to stabilize animals with life-threatening cardiac tamponade, relieve the pressure leading to right-sided heart failure, and obtain fluid samples for diagnostic evaluation. The fluid should be quantified and characterized. Serious complications associated with pericardiocentesis are rare. Complications include cardiac puncture, arrhythmias, and laceration of a tumor or coronary artery resulting in intrapericardial hemorrhage or sudden death.     

Infectious Pericardial Effusion in Five Dogs

The medical records of five dogs diagnosed with infectious pericardial effusion were reviewed. Clinical signs included anorexia, depression, respiratory distress, abdominal distension, collapse, coughing, and vomiting. Anemia and leukocytosis were present in three dogs. Grass awn migration was confirmed as the cause of the pericardial effusion in two dogs and suspected in the other three. Surgery, followed by continuous chest drainage, and appropriate antibiotic therapy was the treatment in four dogs. Chest drains were removed within 4 days of surgery. One dog did not have chest drainage after surgery. Antibiotic treatment was continued for up to 6 months. The dogs were monitored postsurgically for a period ranging from 3 to 24 months. All dogs recovered well without apparent complications.     

Plasma N-terminal pro-brain natriuretic peptide concentrations before and after pericardiocentesis in dogs with cardiac tamponade secondary to spontaneous pericardial effusion

Objective

To determine if concentrations of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) are increased in dogs with cardiac tamponade and if there is a significant increase in plasma NT-proBNP after pericardiocentesis.

Therapy and outcome of suspected alpha lipoic acid toxicity in two dogs

Objective – To report a suspected toxicity in 2 dogs; to discuss therapy and prognosis.
Series Summary – Suspected alpha lipoic acid (ALA) toxicity was diagnosed based on clinical history and compatible laboratory findings in 2 dogs. Case 1 was presented within 10 hours of ALA ingestion, with initial behavioral changes likely due to hypoglycemia. During the course of hospitalization, hypoglycemia persisted and evidence of acute hepatic insult developed. With aggressive supportive care (including IV fluids with dextrose supplementation, hepatoprotective medications, and a plasma transfusion), he made a full recovery. Case 2 was presented approximately 60 hours after ALA ingestion, and was found to be in oliguric renal failure. She was treated with IV fluids, gastroprotective medications, and furosemide, but her condition deteriorated and she was ultimately euthanized within 16 hours of admission to the hospital.
New or Unique Information Provided – ALA is an uncommon but serious toxin that should be considered in cases presenting with hypoglycemia, acute renal failure, or acute hepatic insult.     

Use of oseltamivir in the treatment of canine parvoviral enteritis

Objective – To determine if oseltamivir with standard therapy for canine parvoviral enteritis ameliorates disease morbidity, mortality, or both; to document significant adverse effects associated with its use.
Design – Prospective, randomized, blinded, placebo-controlled clinical trial.
Setting – University veterinary teaching hospital.
Animals – Thirty-five dogs.
Interventions – Standard therapy was administered to all dogs. Treatment dogs also received oseltamivir, while control dogs received an equivalent volume of placebo.
Measurements and Main Results – Dogs were monitored daily according to a clinical scoring system, physical parameters, and diagnostic evaluations. Dogs in the treatment group gained a significant percentage of weight during hospitalization (mean, +2.6%; SD, 7.1%) versus the control dogs (mean, −4.5%; SD, 6.9%) ( P =0.006). Treatment dogs did not have any significant changes in their white blood cell (WBC) count, while control dogs experienced a significant drop in their WBC counts during their initial stay. In addition, it did not appear that oseltamivir use was associated with any major adverse clinical effects.
Conclusions – While a clear advantage to the use of oseltamivir was not established, a significant weight loss during hospitalization, as well as a significant decrease in WBC count were documented in the control group. No major adverse effects were identified that could be associated with oseltamivir administration. Based on these results, the true role of oseltamivir in the treatment of parvoviral enteritis remains speculative, although it is believed that further investigation is warranted.     

Septic pericarditis in a Yorkshire Terrier

Objective: To describe a novel case management strategy for a small breed dog diagnosed with septic pericarditis. Case summary: An 8‐year‐old spayed female Yorkshire Terrier presented for evaluation of pericardial effusion and persistent hypoglycemia. The dog had been hospitalized at a primary care facility for acute onset of vomiting, lethargy, inappetance, and painful abdominal distension. Pericardial effusion was detected and upon referral, cytologic examination revealed a suppurative exudate with Gram‐positive and Gram‐negative bacteria. The dog was treated with pericardiocentesis and placement of an indwelling pericardial catheter. Subtotal pericardiectomy was performed and a thoracotomy tube was utilized postoperatively. A penicillin‐susceptible Bacteroides species was cultured from the pericardial fluid and was treated with a 6‐week course of antibiotics. The dog was discharged from the hospital and clinical signs have not recurred in over 2 years. New or unique information provided: Septic pericarditis, an uncommon cause of canine pericardial effusion, has been described primarily in large breed dogs and in association with bacterial infection secondary to Hordeum grass (foxtail) awn migration. This case was unique in that the dog was a small breed with no evidence of foreign body penetration or other precipitating cause for the pericarditis. In a novel management plan, an indwelling pericardial catheter was employed to stabilize the dog before subtotal pericardiectomy.     

The effect of Hetastarch (670/0.75) in vivo on platelet closure time in the dog

Objective – To evaluate the effect of 6% hydroxyethyl starch (HES) solution in vivo, with an average molecular weight of 670 kDa and degree of substitution of 0.75, on canine platelet function.
Design – Prospective, controlled-experimental study.
Setting – University of California, Davis, Veterinary Medical Teaching Hospital.
Animals – Seven healthy employee-owned dogs.
Interventions – Seven dogs were included in the treatment group. Four of these dogs also served as the control group. Platelet closure time (CT) was measured using a platelet function analyzer and collagen/ADP cartridges. Dogs were given 20 mL/kg of either sodium chloride 0.9% (control group, n =4) or HES (treatment group, n =7) IV over 1 hour. CT was measured before the infusion, and at 1, 3, 5, and 24 hours after the start of the infusion.
Measurements and Main Results – There was a significant change over time from 0 to 24 hours ( P <0.001), a significant difference between groups across time ( P <0.001), and a significant group-by-time interaction ( P =0.007). At 3 hours, mean CT for the treatment group was 122.3±18.1 seconds, which was significantly different ( P <0.001) from the control group (71.0±3.5 s). At 5 hours, mean CT for the treatment group was 142.7±33.9 seconds, which was significantly different ( P =0.001) from the control group (75.0±8.6 s). Mean CT at 24 hours was within the reference interval for both the control and treatment group (66.0±2.9 and 81.8±11.9 s, respectively); however, CT in 3 individual dogs in the treatment group at this time point remained prolonged.
Conclusions – A clinically relevant dose of HES 670/0.75 prolongs CT in dogs for up to 24 hours. This may be due to platelet dysfunction in addition to the effects of hemodilution, and therefore, may increase the risk of bleeding.     

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.     

Resolution of chylopericardium after balloon dilatation of tricuspid valve stenosis in a Labrador Retriever

A 2-year-old 33 kg female castrated Labrador Retriever was referred for exercise intolerance, hyporexia, and abdominal distention. Point-of-care ultrasound revealed ascites, hepatic congestion, severe pericardial effusion, and cardiac tamponade. Pericardiocentesis was performed, and the chylous nature of the fluid was confirmed by cytology, triglyceride, and cholesterol measurements. Repeated pericardiocentesis was necessary within 24-h after admission, after which a pericardial stay-catheter was placed. Cardiac ultrasound revealed severe tricuspid valve stenosis. Balloon dilatation of the stenotic valve was performed, resulting in a significant drop in the mean diastolic trans-valvular Doppler gradient and long-term resolution of the chylopericardium. No other cause for the pericardial effusion could be identified, suggesting that this is the first described case of chylopericardium due to tricuspid valve stenosis.     

A prospective, randomized comparison of Oxyglobin (HB-200) and packed red blood cell transfusion for canine babesiosis

Objective – To establish the efficacy of Oxyglobin (HB-200) in canine babesiosis and compare it to standard therapy, packed red blood cell transfusion (pRBCT) with respect to improvements in specific parameters of blood gas, acid-base, blood pressure, and subjective evaluations.
Design – Prospective, randomized, clinical trial.
Setting – Onderstepoort Veterinary Academic Hospital.
Animals – Twelve dogs (8–25 kg) naturally infected with Babesia rossi and a hematocrit of 0.1–0.2 L/L (10–20%).
Interventions – Treatment groups were randomized to receive either 20 mL/kg of Oxyglobin or pRBCT over 4 hours via a central venous catheter. Transfusions were followed by lactated Ringer's solution infusion. Rectal temperature, femoral arterial and mixed venous blood sampling, oscillometric blood pressure, and subjective assessment of patient status (habitus), and appetite were performed at time points 0, 1, 4, 8, 24, 48, and 72 hours.
Main Results – Dogs presented with a hypoalbuminemic alkalosis; hyperchloremic, dilutional acidosis; normotensive tachycardia; pyrexia; depression; and anorexia. Both treatments produced similar results, with the exception of significant differences in pH (4 h); PCO₂ (4 h); hemoglobin (8 h, 24 h); mean arterial pressure (48 h); albumin (4 h, 8 h); habitus (8 h, 48 h); and appetite (24 h). Arterial O₂ content was higher for pRBCT than Oxyglobin at 72 hours, but central venous PO₂ did not differ between groups or over time and was consistently subnormal.
Conclusions – Oxyglobin provides similar overall improvements to pRBCT in dogs with anemia from babesiosis, with respect to blood gas, acid-base and blood pressure, although patients receiving packed cells tended to have more rapid normalization of habitus and appetite.     

An Investigation of the Action of Neutral Protamine Hagedorn Human Analogue Insulin in Dogs with Naturally Occurring Diabetes Mellitus

Background: Neutral Protamine Hagedorn human analogue insulin (Humulin N) is commonly used for treatment of canine diabetes mellitus (DM). However, blood glucose and serum insulin concentrations in Humulin N-treated dogs with naturally occurring DM have not been reported.
Objective: To investigate blood glucose and serum insulin concentrations in the clinical setting of client-owned Humulin N-treated dogs with naturally occurring, well-regulated DM.
Animals: Ten client-owned dogs with naturally occurring, well-regulated DM.
Methods: In this clinical study, blood glucose and serum insulin concentrations were measured when dogs received food and insulin (T₀), at approximately every half hour for the next 2 hours, and then approximately every 2 hours for an additional 8 hours. Insulin duration of action was defined as the number of hours from T₀ to the lowest blood glucose concentration and until blood glucose concentration returned to an interpolated value of 70% of basal blood glucose concentration (Glucose_b).
Results: Mean percent of insulin-induced blood glucose suppression was 49.9 ± 17.1% (median, 46%; range, 29–78%). Insulin duration of action ranged from 4 to 10 hours. Blood glucose concentration increased initially and returned to Glucose_b within 0.6–2.2 hours after T₀ in 5 dogs. This initial blood glucose surge then was followed by blood glucose suppression in all 5 dogs.
Conclusions and Clinical Importance: These results suggest that Humulin N administered SC twice daily is an effective mode of treatment for dogs with naturally occurring DM. Postprandial hyperglycemia is present in some well-regulated diabetic dogs treated with Humulin N.     

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.     

Surgical treatment of lumbosacral foraminal stenosis using a lateral approach in twenty dogs with degenerative lumbosacral stenosis

Objectives— To describe clinical signs, magnetic resonance imaging (MRI) and surgical findings using a lateral approach to the lumbosacral intervertebral foramen and to evaluate clinical outcomes in dogs with or without concurrent dorsal decompression and annulectomy.
Study Design— Retrospective study.
Animals— Dogs (n=20) with degenerative lumbosacral stenosis (DLSS).
Methods— Medical records (2002–2006) of dogs that had lumbosacral lateral foraminotomy alone or in combination with dorsal decompression were reviewed. Degree of dysfunction was assessed separately for each pelvic limb; dogs with unilateral signs were included in group A, those with bilateral signs in group B. Retrieved data were: signalment, history, neurologic status on admission, 3 days, 6 weeks, and 6 months postoperatively, duration of clinical signs, results of MRI, surgical site(s), intraoperative findings, and outcome.
Results— Based on the clinical and MRI findings unilateral foraminotomy was performed in 8 dogs, bilateral foraminotomy in 1 dog, unilateral foraminotomy with concurrent dorsal decompression in 7 dogs, and bilateral foraminotomy with concomitant dorsal decompression in 4 dogs. Surgery confirmed the presence of foraminal stenosis in all dogs, with osteophyte formation and soft tissue proliferations being the most common lesions. Outcome was good to excellent in 19 dogs and poor in 1 dog. Mean follow-up was 15.2 months (range, 6–42 months).
Conclusion— Lateral foraminotomy addresses compressive lesions within exit and middle zones of the lumbosacral foramen.
Clinical Relevance— Successful surgical management of DLSS is dependent on recognition and correction of each of the compressive lesions within the lumbosacral junction.     

Temporal Variability of Ventricular Arrhythmias in Boxer Dogs with Arrhythmogenic Right Ventricular Cardiomyopathy

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is prevalent in the Boxer. There is little information on the temporal variability of ventricular arrhythmias within affected dogs.
Objective: To evaluate ambulatory electrocardiograms (AECG) from Boxers with ARVC for hourly variation in premature ventricular complexes (PVC) and heart rate (HR).
Animals: One hundred and sixty-two Boxer dogs with ARVC.
Methods: Retrospective, observational study of 1,181 AECGs collected from Boxer dogs at The Ohio State University from 1997 to 2004 was evaluated. The proportion of depolarizations that were PVCs was compared across each hour of the day, during six 4-hour periods of day, to the time after AECG application, and to the maximum and minimum HR.
Results: A lower proportion of PVCs was noted during early morning (midnight to 0400 hours) as compared with the morning (0800–1200 hours) and late (1600–2000 hours) afternoon ( P = .012). There was no increase in PVC proportion in the 1st hour after AECG application as compared with all other hours of the day ( P = .06). There was poor correlation between maximum (ρ= 0.19) and minimum (ρ= 0.12) HR and PVC proportion.
Conclusions and Clinical Importance: The likelihood of PVC occurrence in Boxer dogs with ARVC was relatively constant throughout the day, although slightly greater during the hours of 0800–1200 and 1600–2000. A biologically important correlation with HR was not apparent. The role of autonomic activity in the modulation of electrical instability in the Boxer with ARVC requires further study.