Pyogranulomatous Pancarditis with Intramyocardial Bartonella henselae San Antonio 2 (BhSA2) in a Dog

A 6-year-old, female, spayed American Pitbull terrier was presented for progressive lethargy, weakness, and anorexia of 3-weeks duration. The dog was found as a stray in New York City (NYC) approximately 4 years earlier, assessed to be 2 years of age, and in very poor condition. Pertinent past medical history included a deep hindquarter wound and minor injuries resulting from porcupine encounters. After adoption, the dog lived in NYC, spending summers and weekends in western Massachusetts, running freely on a large property with open fields and woodlands. Before presentation, the dog was healthy and had received routine vaccinations. Ticks were found by her owners on the surface of her fur but were not embedded. Initial physical examination revealed a body weight of 19 kg, pyrexia (103.6°F), and sensitivity over the epaxial muscle region. Clinical pathology abnormalities included mild hypoalbuminemia (2.4 g/dL, range 2.7– 3.9 g/dL), hyperglobulinemia (5.9 g/dL, range 2.4– 4.8 g/dL), and lymphopenia (847/lL, range 1060–4950/ lL). Fecal flotation test results were negative. An injection of meloxicam (dose not provided) was given SC, and metronidazole (20 mg/kg PO q12h) was prescribed for 8 days. During the following week, the dog was reexamined for increasing lethargy, weakness, and pyrexia (103.4°F). Lyme quantitative C6 ELISA (Enzyme linked immunosorbent assay) was negative (<10 U/mL, range <30 U/ mL) . The dog was seroreactive to Anaplasma phagocytophilum (1 : 400) and Ehrlichia canis (1 : 25) antigens by immunofluorescence antibody immunoassay, but was not seroreactive to Rickettsia rickettsii. Doxycycline (10 mg/kg PO q24h) and meloxicam (6 mg/kg PO q24h) were prescribed. When reexamined 4 days later, the patient’s rectal temperature was 100.2°F. Multiple, nonpainful, 1–2 cm diameter, raised cutaneous masses were observed on the left thigh and right ventral abdomen. Punch biopsies were obtained from the 2 ulcerated mass lesions and immediately fixed in formalin, after which the dog was prescribed metoclopramide (0.3 mg/kg PO q12h) and firocoxib (6 mg/kg PO q24h) and referred to the Animal Medical Center (AMC). Upon presentation to the AMC, the dog was hypothermic (95.9°) and eupneic at rest. Respiratory rate and effort increased with ambulation. Thoracic auscultation revealed focal, right-sided, fine, inspiratory crackles, and a sinus arrhythmia. Femoral pulse pressure was synchronous and hypokinetic. Neurological examination revealed lethargic mentation, decreased response to stimuli, and inconsistent conscious proprioceptive deficits. Gentle abdominal palpation elicited cranial and caudal discomfort. Venous blood gas findings were consistent with a metabolic acidosis. The dog was hypoxemic (SpO2, 84%). Oscillometric blood pressure was 109/73 mmHg; however, systolic blood pressure dropped to 70 mmHg during hospitalization. Other laboratory abnormalities included neutrophilia (13.6 K/lL, range, 2.940—12.7 K/lL), thrombocytopenia (51 K/lL, range, 143–448 K/lL), increased alkaline phosphatase (587 U/L, range, 5–160 U/L), aspartate aminotransferase (76 U/L, range, 16–55 U/L) and creatine kinase (320 U/L, range, 10–200 U/L), hypoalbuminemia (1.1 g/dL, range, 2.7–3.9 g/dL), hyperglobulinemia (5.9 g/dL, range, 2.4–4.0 g/dL), hyperbilirubinemia (2.2 mg/dL, range, 0.0–0.3 mg/dL), (unconjugated 1.2 mg/dL, range, 0.0–0.2 mg/dL, conjugated 1.0 mg/dL, range, 0.0–0.1 mg/dL), azotemia (blood urea nitrogen 168 mg/dL, range, 9–31 mg/dL; creatinine 1.9 mg/dL, range, 0.5–1.5 mg/dL), and hyponatremia (124.4 mmol/L, range 135.0–148.0 mmol/L). Thoracic radiographs revealed a diffuse, alveolar pulmonary pattern. From the Department of Pathology, (Donovan); Department of Cardiology, The Animal Medical Center, New York, NY (Fox); Department of Clinical Sciences, Intracellular Pathogens Research Laboratory, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC (Balakrishnan, Breitschwerdt); University of Minnesota Imaging Center, Minneapolis, MN (Ericson); and the The Animal Medical Center, New York, NY (Hooker). Corresponding author: T. Donovan, Department of Pathology, The Animal Medical Center, 510 East 62nd St. New York, NY 10065; e-mail: [email protected]. Submitted January 11, 2016; Revised September 21, 2016; Accepted October 18, 2016. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. DOI: 10.1111/jvim.14609 Abbreviations: