Evaluation of the clinical efficacy and safety of an imidacloprid 10 %/moxidectin 2.5 % spot-on formulation (Advocate®, Advantage® Multi) in comparison to an untreated control group in dogs naturally infected by Capillaria boehmi.

The parasitic nematode Capillaria boehmi inhabits the nasal passages and sinuses of wild and domestic canids, causing either subclinical or clinically signs of varying severity i.e. sneezing, nasal discharge and impairment of scenting ability. The present study investigated the efficacy of imidacloprid 10% / moxidectin 2.5% spot-on (Advocate®/Advantage® Multi, Bayer) in dogs naturally infected by C. boehmi. Twenty dogs were randomly allocated in two groups: T1 (n. 10 dogs) treated with Advocate® at the recommended dose on day 0, and T2 (n. 10 dogs) left untreated. The reduction of the faecal egg counts (EPG) from baseline (days -6 ± 2 and -2 ± 2) to study completion was set as primary efficacy criterion. Clinical assessments and rhinoscopy to visualize the parasites in situ were used as secondary efficacy criteria. Out of the ten T1 dogs, eight did not shed eggs on day 28 ± 2 (reduction of EPG 99.66%) while two were still positive and received a second treatment on day 30 ± 3. A further efficacy evaluation was performed on day 42 ± 2 (study completion), when the two dogs scored negative. The mean EPG at study completion was 0 in T1 and 368.49 in T2, and the difference between the groups was statistically significant (p<0.01). The efficacy at study completion was 100%. T1 dogs showing clinical signs on day 0 fully recovered after treatment and no adverse events occurred. The results show that Advocate® is safe and effective in the treatment of nasal capillariosis of domestic dogs