What is your diagnosis?

A 2 year old, female neutered Shar Pei was presented to the R(D)SVS Emergency Critical Care Service for investigation of acute onset unilateral epistaxis. The dog was a rescue dog from Spain and had been in the owner’s possession for one year. The dog was up to date with vaccines, flea and worming treatment. The dog had no previous medical conditions apart from some mild hyperkeratosis on the pads and occasional sneezing over the last year. On physical examination, the dog was bright, alert and responsive. The heart rate was 126 beats per minute with no arrhythmia and good pulse quality. Systolic blood pressure was 138mmHg. There was no abnormal respiratory noises audible on thoracic auscultation although the dog was very tachypneic at 84 breaths per minute. The oral mucous membranes were pink and moist, capillary refill time was 2 seconds and skin turgor was normal. Abdominal palpation was unremarkable and all peripheral lymph nodes were within normal limits. The rectal temperature was 39.1°C. There was moderate bleeding from the left nostril, which was causing the dog anxiety and discomfort.