Rabbit Medicine and Surgery Q&A 15

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A seven-year-old intact male English rabbit, housed indoors, presents with acute onset tachypnoea and laboured breathing. There is a three-month history of weight loss, hindlimb weakness and rapid fatigue. The rabbit is alert, thin and weak. The mucous membranes are pale, with prolonged capillary refill time. A good response is noted to oxygen administration. The rabbit is sedated with intravenous midazolam and lateral and ventrodorsal radiographs of the thorax are taken.

Question	Answer		Article
What are the differential diagnoses in this case?	Congestive heart failure (myocardial, valvular and congenital disease) is seen in middle-aged to older rabbits. The weakness, weight loss and rapid fatigue observed, although non-specific signs, should arouse suspicion of cardiac or lower respiratory disease. Other differentials include: pyothorax – pleuropneumonia typically due to pasteurellosis but other bacterial agents are often involved; modified transudates seen secondary to neoplasia, lung lobe torsion or diaphragmatic hernia; haemothorax – seen in viral haemorrhagic disease, coagulopathies or trauma.		Link to Article
Based on the radiographic findings, what immediate treatment would you consider?	The radiographs show a pleural effusion. Immediate thoracocentesis will help stabilize the rabbit as well as determine the type of effusion. Drain the thorax bilaterally using a 23 gauge butterfly catheter placed ventrally in the chest wall. Remove as much fluid as possible by aspirating multiple sites. Oxygen should be provided via a face mask during this procedure and stress should be kept to a minimum. Sedation is often not required in debilitated animals, although diazepam (0.5–1 mg/kg i/v or i/m) or midazolam (1–2 mg/kg i/v or i/m) may be used if necessary. In this case 20 ml of a serosanguinous fluid was obtained from both left and right sides of the chest. It was found to be a modified transudate with a protein of 22.4 g/l (2.4 g/dl) (ref: 25–30 g/l [2.5–3 g/dl]) and a nucleated cell count of 2 × 109/l (2000/μl) (ref: 1–7 × 109/l [1000–7000/μl]). No organisms were cultured.		Link to Article
What further diagnostic tests might be helpful?	Once the rabbit is stable the thoracic radiography is repeated to evaluate fully the thoracic contents. Echocardiography should be carried out to characterize any cardiac disease further. Electrocardiography, blood pressure measurement and routine blood tests are useful in reaching a definitive diagnosis and treatment plan.		Link to Article