nal haemorrhages and prolonged bleeding from wounds or after surgery (Ramsey and others 1996, Brennan and others 2004, Morgan and others 2005). In neurological cases, paresis, depression, seizures, spinal pain, behavioural changes, ataxia and loss of vision have been described as potential results of aberrant nematode migration or subdural haemorrhage (Patteson and others 1993). This short communication reports on five fatal, presumably autochthonous, cases of A vasorum infection in dogs from northern England and the West Midlands that occurred within the last six months and were only diagnosed by means of a full postmortem examination. Case 1 A one-year-old neutered male labrador was referred to the Small Animal Teaching Hospital, at the University of Liverpool, as an emergency case following epistaxis and collapse on April 14, 2008. The owner reported that the dog had been born in and lived in Manchester, Lancashire. It had not travelled outside this area and had not undergone any prophylactic worming. The dog had a history of profuse bleeding after neutering two months previously. Epistaxis had begun four weeks before referral. The animal was comatose on presentation at the hospital. It was hyperthermic (39•8°C) and neutrophilic (13•9 x 10 9 /l, reference range 2•00 to 12•00 10 9 /l), and had a mildly decreased platelet count (142•000 µl, reference range 175 to 500 µl) and an elevated sodium level (163 mmol/l, reference range 144 to 160 mmol/l). Mucosal bleeding time was four minutes 30 seconds and within normal limits. The wholeblood clotting time was prolonged to more than two hours. Neurological examination revealed right-sided Horner's syndrome and a lack of papillary and gag reflexes, while palpebral reflexes were present. Ophthalmic examination did not provide evidence of retinal haemorrhage. Thoracic radiographs showed a marked alveolar pattern affecting most of the lung fields. Magnetic resonance imaging identified marked subdural haemorrhage with compression of the cerebrum and brainstem and cerebellar herniation. The dog's prognosis was poor. It was euthanased and a postmortem examination was performed. Grossly, focal subdural haemorrhage over the left hemisphere with compression of the left occipital and parietal lobes was observed. The lungs were diffusely reddened and consolidated. Histological examination of the brain confirmed the gross findings and identified occasional intravascular nematode larvae. The main findings in the lungs were multifocal haemorrhages and/or granulomatous infiltrates, in association with variable numbers of nematode eggs, also seen within alveoli and larger blood vessels. Eggs were oval, thin walled and approximately 50 to 90 µm in diameter, and contained fine eosinophilic granules. Larvae were approximately 15 µm wide and contained basophilic and eosinophilic granular material. Adult nematodes were occasionally seen within larger blood vessels (cross sections). They had a width of 265 to 308 µm and exhibited a thin smooth cuticle, a thin hypodermis with lateral cords, ...