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.     

Idiopathic pericarditis and cardiac tamponade in two cows

Idiopathic pericarditis is an uncommon diagnosis in cattle with cardiac tamponade. Two cows were examined for clinical signs of right-sided congestive heart failure, including tachycardia, venous distention, and peripheral edema. Muffled heart sounds were detected in one of the cows. Echocardiography in both cows revealed voluminous anechoic pericardial effusion and compression of the right atrium and right ventricle. Cytologic analysis of the pericardial fluid revealed hemorrhagic inflammation but no evidence of a septic or neoplastic condition such as traumatic reticulopericarditis or lymphoma, respectively. Pericardial drainage and lavage accompanied by treatment with anti-inflammatory drugs were curative in both cows. It is important to differentiate cows with idiopathic pericarditis from cows with more common septic pericarditis because the prognosis for the former disease appears to be good with appropriate treatment.     

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.     

Two-dimensional echocardiographically guided pericardiocentesis in a horse with traumatic pericarditis

Two-dimensional echocardiographic (2DE) examination was performed on a horse with clinical signs of pericardial effusion. Thickening of the pericardium, excess amount of pericardial fluid, elevation of the cardiac apex, and right ventricular compression, characteristic of cardiac tamponade, could be seen on 2DE recordings. Fibrinous pericarditis was suspected by observation of fibrinous strands in the pericardial fluid and epicardial fibrin deposits. Echocardiographically guided pericardiocentesis was performed, and 4 L of fluid was removed from the pericardial sac. Streptococcus zooepidemicus was isolated from the fluid. Pericardiocentesis was repeated for 3 days, and medication was administered. Despite temporary improvement in cardiac function, the horse's condition deteriorated gradually, and euthanasia was performed on the ninth day of hospitalization. Necropsy revealed chronic serofibrinous pericarditis of traumatic origin, attributable to an intercostal stab wound entering the pericardium and the apical portion of the myocardium.     

Idiopathic systemic granulomatous disease with encephalitis in a horse

A 14-year-old standardbred mare with clinically suspected acute bronchitis was killed because of rapidly progressing central nervous disturbances. Necropsy revealed systemic granulomatous inflammation and vasculitis involving the lungs, thoracic lymph nodes, ribs, and liver. In the cerebrum there was a severe subacute bilateral encephalitis and malacia predominately affecting the white matter, and vasculitis with perivascular infiltration of lymphocytes, macrophages, and giant cells. A causative infectious agent could not be detected by Ziehl-Neelsen, Grocott, or Giemsa stains, by periodic acid-Schiff reaction of tissue sections, nor by bacterial and fungal cultures. Therefore, idiopathic systemic granulomatous disease (ISGD) was diagnosed and an immune-mediated pathogenesis was suspected. Inflammatory involvement of the brain has hitherto not been reported in cases of equine ISGD. This case seems to be an uncommon variant of ISGD with encephalitis and lack of dermal involvement.     

Idiopathic infectious arthritis of the coxofemoral joint in a mature horse

The authors are aware of only one previously described case of idiopathic infectious arthritis of the coxofemoral joint in a mature horse. The case described herein presented with clinical signs that localised pain to the proximal limb, subtle increased radiopharmaceutical uptake at the coxofemoral joint and an increase of the major acute phase protein, serum amyloid A in the horse's blood biochemistry. The latter finding led the authors to search initially for an infective process. Ultrasound guided aspiration of the coxofemoral joint yielded infected synovial fluid. Despite the duration of the condition, nonsurgical treatment allowed the horse to return to its previous, relatively modest, level of activity. This case is presented to supplement the single previously published case report of idiopathic adult coxofemoral infectious arthritis in the horse.     

Idiopathic pericarditis in dogs: no evidence for an immune-mediated aetiology

OBJECTIVE: To ascertain whether specific immunological changes are associated with canine pericardial effusion due to idiopathic pericarditis. METHODS: In this prospective study, serum antinuclear antibody and serum and pericardial fluid immunoglobulin (Ig) G, Ig M and Ig A concentrations were measured in dogs with pericardial effusion due to idiopathic pericarditis or pericardial neoplasia. The secretory index relative to albumin concentration was calculated in order to distinguish between Ig actively secreted into the pericardial fluid and that derived from the blood accumulating within the pericardial sac. Statistical analysis was performed comparing the results obtained between the two groups of dogs. RESULTS: Only three dogs were antinuclear antibody positive; two of these dogs had idiopathic pericarditis and one had neoplasia. Mean serum Ig M and Ig A concentrations were lower than the reference values in both groups, and the secretory indices for Ig M and Ig A were greater than 1.0. However, there was no significant difference with respect to any Ig measurement between the two groups of dogs (P>0.1). CLINICAL SIGNIFICANCE: The results of the present study do not support the hypothesis that canine idiopathic pericarditis has a significant 'immune-mediated' aetiology or immunological features that distinguish it from the pericardial changes associated with local neoplastic disease.     

Idiopathic arterial medial calcification of the thoracic arteries in an adult horse

A 6-year-old, gelded, Paint horse displayed clinical signs of muscle wasting and limb stiffness for a 6-month period. The horse's clinical signs abated with corticosteroid therapy, but returned upon cessation of treatment. Upon necropsy, severe lesions of aortic thickening and aortic valve rigidity were observed. Histologically, the tunica media of the aorta, coronary arteries, and pulmonary arteries were expanded by foci of elastin fiber calcification and extracellular matrix with lacunae formation. The vascular lesions are comparative to what has been described as medial arterial calcification, seen in humans suffering from chronic renal failure or diabetes mellitus. No exposure to vitamin D-containing plants or feedstuff could be documented at the time of onset or during the period of clinical signs. The current case describes dramatic lesions of arterial medial calcification of the aorta, coronary, and pulmonary arteries of undetermined cause.     

Use of an insect cell culture growth medium to isolate bacteria from horses with effusive, fibrinous pericarditis: a preliminary study

Effusive, fibrinous pericarditis is an uncommon disease entity in horses. In 2001, pericarditis occurred in conjunction with an epizootic in central Kentucky that was associated with exposure to eastern tent caterpillars (ETCs). Bacterial isolation from equine pericardial fluid samples was attempted using an insect cell culture growth medium (ICCGM). Using previously cultured, stored frozen samples from four horses with fibrinous pericarditis, inoculation of 10% blood agar plates yielded no growth, whereas simultaneous inoculation of ICCGM resulted in the isolation of Proprionibacterium acnes, Staphylococcus equorum, a Streptococcus sp. and Pseudomonas rhodesiae from pericardial fluid samples. A similar or novel caterpillar-associated bacteria was not identified; however, use of an ICCGM might enhance isolation of bacteria from equine pericardial fluid.     

Idiopathic muscular hypertrophy of the oesophagus in the horse: a retrospective study of 31 cases

REASONS FOR PERFORMING STUDY: To present the first report of a case series concerning equine idiopathic muscular hypertrophy of the oesophagus (IMHO). OBJECTIVES: To investigate the clinical and pathological features of the disorder. METHODS: The medical records of 31 horses suffering from the disorder were reviewed retrospectively. In all these animals the diagnosis was confirmed at post mortem examination. RESULTS: The median age of the affected horses was 12.5 +/- 5.6 years (range 1-26) without sex or breed predilection. Only 2 out of 31 horses showed clinical signs associated with oesophageal dysfunction, indicating that the muscular hypertrophy was rather a coincidental post mortem finding. Histology revealed thickening of the distal portion of the oesophagus mainly involving the circular layer of the tunica muscularis without fibrosis or inflammation. In 8 cases, the disorder was seen in concurrence with idiopathic hypertrophy of the tunica muscularis of various other parts of the gastrointestinal tract. CONCLUSIONS: In the majority of patients, IMHO was a coincidental finding at post mortem examination usually confined to the smooth, circular muscle layer of the tunica muscularis externa. POTENTIAL RELEVANCE: Further research is necessary to study the precise effect of IMHO on oesophageal function.     

Total intravenous anaesthesia in the horse with propofol

The use of propofol, solubilised in a non-ionic emulsifying agent, for the induction and maintenance of anaesthesia in experimental ponies was assessed. Pilot studies revealed that premedication with xylazine (0.5 mg/kg bodyweight [bwt]) intravenously (iv) followed by propofol (2.0 mg/kg bwt) iv provided a satisfactory smooth induction. Two infusion rates (0.15 mg/kg bwt/min and 0.2 mg/kg bwt/min) were compared for maintenance of anaesthesia. An infusion rate of 0.2 mg/kg/min produced adequate anaesthesia in these ponies. Cardiovascular changes included a decrease in arterial pressure and cardiac output during maintenance. Respiratory depression was manifested by a decrease in rate and an increase in arterial carbon dioxide tension. Recovery after 1 h anaesthesia was rapid and smooth. In conclusion, induction and maintenance of anaesthesia with propofol in premedicated ponies proved a satisfactory technique.