Serological and faecal detection of Angiostrongylus vasorum in dogs from Austria

Canine angiostrongylosis is a potentially lethal parasitic disease that can manifest itself with a broad spectrum of clinical signs, including respiratory distress, neurological and bleeding disorders, or non-specific signs. The occurrence of Angiostrongylus vasorum is widely reported in Europe, but very little is known about its presence in Austria. In this first large-scale survey, 1279 sera were collected from Austrian dogs and tested by an ELISA for the detection of circulating antigen of A. vasorum (sensitivity: 95.7%, specificity 94.0%) and by a separate ELISA detecting specific antibodies (sensitivity 81.0%, specificity 98.8%). Furthermore, 1040 faecal samples were tested for the presence of lungworm first stage larvae (L1). One dog (0.1%, 95% confidence intervals [CI]: 0.0-0.4%) was positive in both ELISAs, while 1.2% (n = 15, CI: 0.7-1.9%) of the tested dogs were antigen-positive and 1.5% (n = 19, CI: 0.9-2.3%) were positive for specific antibodies. Overall, 13 dogs (1.3%; CI: 0.7-2.1%) were positive for A. vasorum L1 while 31 dogs were positive for Crenosoma vulpis L1 (3.0%; CI: 2.0-4.2%). One dog shed L1 from both A. vasorum and C. vulpis (0.1%, CI: 0.0-0.5%). Dogs positive for A. vasorum originated from northeast, southeast and south Austria (antigen and/or antibody detection), but also from north, west and southwest Austria (antibody detection) and from northeast and west Austria (L1 detection). One of 88 blood samples (1.1%, CI: 0.0-6.2%) submitted from the eastern part of Austria was positive by a rapid assay for A. vasorum antigen detection (Angio Detect™). Crenosoma vulpis positive samples originated from northwest, north, northeast, south and west Austria. These results confirm the very sporadic occurrence of A. vasorum in the investigated areas of the country. However, due to the substantial infectious pressure from the surrounding countries and the free circulation of dogs and foxes acting as wildlife reservoirs and due to clinical relevance for infected dogs, it is crucial to maintain disease awareness also in areas where the parasite has not yet been detected.