Increased prevalence and geographic spread of the cardiopulmonary nematode Angiostrongylus vasorum in fox populations in Great Britain

Abstract

The nematode Angiostrongylus vasorum is becoming more widely recorded globally, and is of increasing concern as a cause of disease in dogs. Apparent geographic spread is difficult to confirm due to a lack of standardized disease recording systems, increasing awareness among veterinary clinicians, and recent improvements in diagnostic technologies. This study examines the hypothesis that A. vasorum has spread in recent years by repeating the methods of a previous survey of the fox population. The hearts and lungs of 442 foxes from across Great Britain were collected and examined by dissection and flushing of the pulmonary circulation and microscopic inspection of tracheal scrapes. Sampling and parasite extraction methods were identical to an earlier survey in 2005 to ensure comparability. Prevalence of A. vasorum was 18·3% (exact binomial confidence bounds 14·9-22·3), compared with 7·3% previously (5·3-9·9, n = 546), and had increased significantly in most regions, e.g. 7·4% in the Northern UK (previously zero) and 50·8% in the south-east (previously 23·2%). Other nematodes identified were Crenosoma vulpis (prevalence 10·8%, CI 8·1-14·2) and Eucoleus aerophilus (31·6%, CI 27·3-36·2). These data support the proposal that A. vasorum has increased in prevalence and has spread geographically in Great Britain.

Unexplained bleeding as primary clinical complaint in dogs infected with Angiostrongylus vasorum

“…This has changed remarkably over the last decade, and the disease is now very commonly diagnosed. Besides increased veterinary practitioner awareness, factors underlying this trend could be effect of longterm climate change on intermediate host availability and/or parasite development rate, increasing dog movement, or increasing transmission through the fox population (Taylor et al, 2015).…”

Evaluation of the Persistent Preventive Efficacy of 2.5 % Moxidectin/10 % Imidacloprid Spot-on (Advocate®, Advantage® Multi) in Dogs Experimentally Infected with Angiostrongylus vasorum

“…In four of these eight dogs also arterial thrombi could be found. Growing prevalence in dogs and wildlife has been reported for A. vasorum (Taylor et al 2015, Barutzki et al 2017. There is also evidence for a growing infection rate in snails (Aziz et al 2016).…”

“…A commercial antigen test for dog serum is now also available (AngioDetectTM, IDEXX Laboratories, Ludwigsburg, Germany). Epidemiological surveys indicate that the prevalence of A. vasorum infection in dogs and foxes is increasing in various European countries (Traversa et al 2013, Taylor et al 2015. A significant increase in the prevalence of A. vasorum from 0.9 % in 2004 -2006 to 1.8 % in 2012 -2016 was found in a retrospective analysis of canine faecal samples from Germany (Barutzki et al 2017).…”

Lungworms in Germany 2002 – 2016: Is there an Increase in Occurrence and Geographical Spread?

“…This may reveal higher prevalence rates, a regional spread, or a combination of both. One of the first studies to look into this was a comparison of the prevalence and regional distribution of A. vasorum studied in a fox population in the UK, where data from 2005(Morgan et al 2008 were compared with data from 2013/2014 using identical methods (Taylor et al 2015). It was concluded that the prevalence of A. vasorum increased from 7.3% to 18.3% (exact binomial confidence limits 14.9 -22.3).…”