Pulmonary hypertension associated with Ehrlichia canis infection in a dog

CANINE monocytic ehrlichiosis (CME) is an important canine disease with a worldwide distribution. The clinical presentation can be acute, subclinical or chronic, and there may be a multitude of clinical manifestations (Neer 1998, Neer and others 2002, Cohn 2003, Harrus and Waner 2011). This report describes a case of severe pulmonary hypertension (PH) in a dog infected with Ehrlichia canis , which completely resolved after treatment. A seven-year-old, neutered female Yorkshire terrier, weighing 5.5 kg, was presented to the Cardiology Service of the Veterinary Teaching Hospital of Milan with a one-month history of syncope and a one-week history of anorexia and abdominal distension. The dog was housed indoors, its vaccination programme was up to date and it received monthly heartworm-prevention treatment during the warm season. Every August, the dog spent a month in a tick-endemic area (the island of Sardinia, Italy). On physical examination, the dog showed generalised weakness, dyspnoea, pale mucous membranes, prolonged capillary refill time, jugular distension and pulse, a weak femoral pulse, generalised moderate lymph node enlargement, right systolic heart murmur (grade 3/6), abnormal lung sounds and marked abdominal distension. Body temperature was 38.6°C. These findings were consistent with right-sided congestive heart failure (RCHF) and poor peripheral perfusion. Complete blood count (CBC) and biochemistry showed a mild normocytic normochromic anaemia, leucocytosis with marked lymphocytosis, moderate thrombocytopenia, severe hyperproteinaemia, hyperglobulinaemia, hypoalbuminaemia and increased plasma C-reactive protein (Table 1). Serum protein electrophoresis showed a narrow peak in the gammaglobulin region suggesting an oligo- or monoclonal gammopathy. Cytological evaluation of aspirates from peripheral lymph nodes showed a prevalent population of small lymphoid cells with signs of reactive lymphoid hyperplasia. Cytological examination of a bone marrow aspirate showed mild hypoplasia of erythroid and megakaryocytic lineages and an increased percentage of small lymphocytes (about 20 per cent of total …