Prevalence of Angiostrongylus vasorum in southern Belgium, a coprological and serological survey

Abstract

BackgroundCanine angiostrongylosis, a gastropod-borne helminthic infection, is increasingly being described in North America and is now reported in many European countries. In dogs, Angiostrongylus vasorum may cause a wide spectrum of clinical signs. Respiratory distress such as coughing and dyspnoea are the most frequently described manifestations. The aim of the present study was to gain additional information on the distribution, prevalence and risk factors associated with A. vasorum infection in dog from southern Belgium through the combined used of a commercially available in-clinic assay for detection of circulating antigen (Angio Detect™, IDEXX, Westbrook, USA) and coprology in two different canine populations: dogs with clinical signs compatible with angiostrongylosis and asymptomatic dogs or dogs presented for unrelated conditions (control).ResultsA total of 979 dogs were enrolled in the study from November 2014 until February 2016. Seven hundred fifty-seven dogs were included in the control group, whereas 222 dogs had clinical signs compatible with angiostrongylosis. Forty-six dogs out of 979 (4.7 %) had A. vasorum circulating antigen. There was a highly significant difference between the two populations (3.6 % (27/747) and 8.6 % (19/222) in control and symptomatic dogs, respectively) (P = 0.00379). First stage larvae (L1) of A. vasorum were found in seven out of 24 serologically positive control dogs and in six out of 17 serologically positive symptomatic dogs. Interestingly, L1 of Crenosoma vulpis were detected by Baermann technique in one control and nine symptomatic dogs, respectively. Out of 17 Angio Detect™ (IDEXX, Westbrook, USA) positive dogs with negative (14) or not performed Baermann test (three), one dog was positive in both in-house ELISAs (Ag and Ab) and one dog was positive for Ag. Statistical analysis was unable to detect any risk factors associated with the direct and/or indirect detection of A. vasorum.ConclusionsThis seroepidemiological study demonstrated for the first time a high seroprevalence in Southern Belgium for A. vasorum. The Angio Detect™ was found to be suitable in this context as the collection, preservation and examination of stools were difficult. Nevertheless, discrepancies were observed between the different available tests. Additional research is clearly needed. Also, coproscopy remains a very useful tool in dogs infected for less than nine weeks and for the identification of other canine lung nematodes such as C. vulpis. This study also demonstrates that asymptomatic dogs may shed A. vasorum L1 in their faeces and therefore contribute to the maintenance of A. vasorum life-cycle.

Angiostrongylus vasorum, “The French Heartworm”: a Serological Survey in Dogs from France Introduced by a Brief Historical Review

“…In German regions neighbouring to France, based on a study with more than 12,000 dogs analysed between 2003-2015, the prevalence of A. vasorum was between 0 and 8.7 % (Maksimov et al 2017). Also in Belgium, the presence of A. vasorum has been increasingly reported (Canonne et al, 2015), including areas bordering France (Lempereur et al 2016). Limited information is available from areas bordering the western part of France: a prevalence of 3.4 % was observed in foxes from the Spanish Pyrenees and Catalonia (Garrido-Castane et al 2015).…”

Filaroidosis infection in an immunocompetent adult dog from France

“…Based on their signifi cantly smaller size and on their tails showing a notch followed by a constriction and a terminal lancelike end, without any kink, undulation or spine, isolated larvae were distinguished from those of A. vasorum showing a prominent dorsal spine and a double cuticle indentation at the caudal end (McGarry & Morgan, 2009;Traversa et al, 2010;Taylor et al, 2007). The different morphology of the caudal end also allowed their differentiation from L1s of C. vulpis, showing a straight and uniformly pointed tail (McGarry & Morgan, 2009;Traversa et al, 2010). The L1s of F. hirthi, Filaroides milksi and Oslerus (Fila roides) osleri are morphological identical and cannot be differentiated from each other (Traversa et al, 2010;Conboy, 2009).…”

“…Therefore, a different antigen-based assay (Schnyder et al, 2011) with a positive result for the detection of A. vasorum was performed. Additionally, based on morphology and dimensions according to previously reported data (McGarry & Morgan, 2009) the L1s found in BALF were microscopically identifi ed at the species level. The collected L1s measured 265 ± 13μm and were characterised by a straight tail with a single slight dorsal indentation, ending in a lance-like shape (Fig.…”

“…Canine F. hirthi infection is usually marked by dry cough (Bowman, 2000) along with rapid breathing, dyspnoea, and exercise intolerance (Rubash, 1986;Andreasen & Carmichael, 1992;Bourdeau & Ehm, 1992). The diagnosis of the infection is based on direct detection of L1s in bronchoalveolar lavage or in the faeces (Pinckney et al, 1988;McGarry & Morgan, 2009). However, due to intermittent faecal larval shedding and the occurrence of auto-reinfections, the diagnosis and treatment of canine F. hirthi infection remain challenging (Bauer & Bahnemann, 1996).…”

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

“…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). In addition, there are new reports on the occurrence of A. vasorum infections in dogs and wildlife from countries where A. vasorum was previously not observed (Hurniková et al 2013, Lempereur et al 2016, Penagos et al 2016. After ingestion of a snail or slug containing thirdstage larvae (L3) of A. vasorum, or even ingestion of grass or dog food contaminated with the slime of an infected gastropod (Ferdushy andTabarak 2010, Conboy et al 2017), the L3 penetrates the intestinal wall and migrates to the abdominal lymph nodes, where it moults into fourth-stage larvae (L4) and immature adults.…”