Emerging canine angiostrongylosis in northern England: five fatal cases

Abstract

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, ...

Angiostrongylus vasorum in Great Britain: a nationwide postal questionnaire survey of veterinary practices

“…Knowledge of the distribution of A. vasorum in dogs in the UK was based, prior to the present study, either upon published reports of clinical cases seen in southwestern England, south Wales, southeastern England and, more recently, the West Midlands, northern England and Scotland or published lab studies testing large number of serum samples that were originally collected for miscellaneous diagnostic purposes across the UK and subject to secondary testing for the detection of A. vasorum (Jacobs and Prole 1975, Simpson and Neal 1982, Patteson and others 1987, Trees 1987, Chapman and others 2004, Helm and others 2009, Yamakawa and others 2009, Schnyder and others 2013a). Larger-scale clinical studies, such as Blehaut and others (2014), who described a retrospective study of 142 clinical cases, submitted to the Royal Veterinary College between April 1999 and July 2012, have sought to address the distribution of clinical cases on a regional basis (southeastern England).…”

“…Over the following two decades, many more cases were recorded in Wales (Patteson and others 1987, Trees 1987) and southeastern England (Chapman and others 2004). A survey of nematode parasites of wild foxes in England later and more recently in Scotland suggested that the parasite may be spreading further north (Morgan and others 2008, Philbey and Delgado, 2013), and this was supported by a report of five fatal cases of A. vasorum infection in dogs from northern England and the West Midlands (Yamakawa and others 2009), a case in Glasgow (Helm and others 2009) and a laboratory study using serum samples from dogs with a range of conditions across the UK (Schnyder and others 2013a). Yet despite the increasing number of reports of canine angiostrongylosis at a regional level, there has as yet been no attempt to establish the distribution of infection in dogs on a nationwide scale and formally assess potential clustering of cases.…”

Epidemiological survey of Angiostrongylus vasorum in dogs and slugs around a new endemic focus in Scotland

“…A veterinary practice-based questionnaire identified reports of canine angiostrongylosis in Scotland and northern England, but in lower numbers than further south (Kirk and others 2014), and these could be in dogs originally infected elsewhere. Confirmed records of angiostrongylosis in dogs in the north of England are published but in small numbers and not in the far north of the UK (Yamakawa and others 2009). Further information on the epidemiology of the parasite in the northern UK is needed, to guide efforts to control the disease (e.g.…”

Spatial, demographic and clinical patterns of Angiostrongylus vasorum infection in the dog population of Southern England

“…The combination of data from veterinary clinics distributed throughout the country allows a more extensive picture of disease distribution to be drawn and is the subject of an accompanying paper, in which Kirk and others (2014) show that A. vasorum infection has spread beyond traditional endemic foci and is now widespread in central England with clusters of infection in the southeast of England and South Wales. Such studies complement the discovery of cases from other referral centres including Liverpool (Yamakawa and others 2009) and Glasgow (Helm and others 2009). …”