CASE 6 A 7-year-old intact male English rabbit, housed indoors, presents with acute onset tachypnoea and laboured breathing. There is a 3-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 (6a, b).