Case Report: Septic Pericarditis With Achromobacter xyloxidans in an Immunosuppressed Dog

Abstract

A 5-year-old female spayed French Bulldog presented for anorexia and increased respiratory rate. On presentation, she was dyspneic with stridor and increased bronchovesicular sounds. Point-of-care ultrasound identified pericardial effusion. Thoracic radiographs identified pleural effusion, a wide cranial mediastinum, and multifocal unstructured interstitial pulmonary opacities. Bloodwork revealed a moderate leukocytosis characterized by a mature neutrophilia with a left shift, hypoalbuminemia, mildly increased alkaline phosphatase activity, and moderate hypokalemia. Thoracic CT findings revealed moderate pericardial and bilateral pleural effusion, mediastinal effusion, and moderate cranial mediastinal lymphadenopathy. Diagnostic thoracocentesis and pericardiocentesis revealed septic exudates with bacilli. Two days later, a median sternotomy and pericardiectomy were performed. Aerobic cultures of the effusions grew Achromobacter xylosoxidans ss deitrificans. The patient was treated with Amoxicillin-clavulanate and enrofloxacin for 12 weeks and clinically fully recovered. Achromobacter xylosoxidans has not been reported as a cause of purulent pericarditis and pyothorax in a dog. Uniquely, this patient is suspected of developing this infection secondary to immunosuppression.

Successful medical management of septic pericardial effusion in a dog

“…Similar to our case, a recent report 12 describes a dog that developed Achromobacter xyloxidans purulent pericarditis and pyothorax as a consequence of long-term administration of immunosuppressive doses of prednisolone for the treatment of inflammatory bowel disease and atopy. In contrast to our case, the dog was successfully treated with a combination of pericardiectomy and antibiotic therapy.…”

“…13 The use of multiple immunosuppressant drugs has been associated with pericardial opportunistic infections development. 12 The dual, high-dose immunosuppressive combination administered for 9 weeks likely resulted in this opportunistic infection.…”

“…Second, the most common causes of pericardial effusion were not identified, thus iatrogenic immunocompromised status of the dog with consequent increased susceptibility to infections was considered the precipitating factor for the development of septic pericarditis. 12 Based on the ACVIM diagnostic algorithm for IMHA diagnosis, the dog had suspected immune-mediated haemolytic anaemia and had been started on cyclosporine at 5 mg/kg twice daily plus a higher than recommended dosage of prednisolone 5 mg/kg/day before referral. 13 The use of multiple immunosuppressant drugs has been associated with pericardial opportunistic infections development.…”

“…First, septic pericarditis most commonly affects large breed dogs, 11 making this case more unusual, given that this dog was a medium‐sized breed. Second, the most common causes of pericardial effusion were not identified, thus iatrogenic immunocompromised status of the dog with consequent increased susceptibility to infections was considered the precipitating factor for the development of septic pericarditis 12 . Based on the ACVIM diagnostic algorithm for IMHA diagnosis, the dog had suspected immune‐mediated haemolytic anaemia and had been started on cyclosporine at 5 mg/kg twice daily plus a higher than recommended dosage of prednisolone 5 mg/kg/day before referral 13 .…”

“…Based on the ACVIM diagnostic algorithm for IMHA diagnosis, the dog had suspected immune‐mediated haemolytic anaemia and had been started on cyclosporine at 5 mg/kg twice daily plus a higher than recommended dosage of prednisolone 5 mg/kg/day before referral 13 . The use of multiple immunosuppressant drugs has been associated with pericardial opportunistic infections development 12 …”