Determining resolution of Angiostrongylus vasorum in dogs following anthelmintic treatment with an imidacloprid 10 per cent/moxidectin 2.5 per cent spot-on

Objectives To determine the time from treatment with a product containing imidacloprid 10 per cent/moxidectin 2.5 per cent spot-on (Advocate™), to dogs becoming negative for Angiostrongylus vasorum (A. vasorum). The authors hypothesised that most dogs would have resolution of A. vasorum within four weeks of treatment with Advocate™. Design Prospective, non-randomised, prepost treatment study. Setting Cases were enrolled from general practices along the southern coast of the United Kingdom. Participants Nine dogs completed the study and were enrolled if A. vasorum had been diagnosed based on a positive commercially available, in-clinic, serological A. vasorum antigen test (Angio Detect®) or Baermann performed at an external laboratory or both. Interventions The only treatment A. vasorum-positive dogs received was Advocate™ which was applied at the time of diagnosis and reapplied if necessary at four-weekly intervals until dogs tested negative by Angio Detect. Primary outcome measures Angio Detect® was performed and Advocate™ was reapplied at four-weekly intervals until dogs tested negative by this method. Secondary outcome measures Baermann was also performed at four-weekly intervals until dogs tested negative by this method. Results Application of Advocate™ was an effective treatment for A. vasorum infection in dogs and resulted in resolution of the infection, based on Angio Detect® testing and Baermann, within four weeks, in eight out of nine dogs. Post-treatment Angio Detect® testing was concordant with Baermann in seven of nine dogs. Conclusions Application of Advocate™ was an effective treatment for A. vasorum infection in dogs and resulted in resolution of the infection within four weeks in most dogs. Repeat Angio Detect® testing is recommended following treatment of A. vasorum to confirm resolution of the infection.