Monthly application of 10 per cent moxidectin and 2.5 per cent imidacloprid spot-on to prevent relapses in generalised demodicosis : a pilot study

Canine generalised demodicosis (GD) can be difficult to cure, with some dogs requiring life-long treatment. The aim of this pilot study was to evaluate the effectiveness of monthly 10 per cent moxidectin/2.5 per cent imidacloprid spot-on in maintaining long-term (12 months) clinical and parasitological remission in dogs with relapsing GD. Fourteen dogs were included: 10 with juvenile-onset GD (JOGD) and four with adult-onset GD (AOGD). All dogs had been treated previously and relapsed (1–4 times). Each dog was treated again with either milbemycin oxime 2 mg/kg or ivermectin 400 μg/kg orally once daily, until two consecutive negative skin scrapings at one-month intervals (total 4–7 months of treatment). After treatment discontinuation, 10 per cent moxidectin/2.5 per cent imidacloprid spot-on was applied monthly for 12 months. Dogs were rechecked after 1, 2, 3, 6 and 12 months, and multiple skin scrapings were taken. Twelve dogs completed the study and were clinically normal and parasitologically negative at each recheck (four dogs with AOGD and eight with JOGD). One dog died suddenly for unrelated reasons, and one dog relapsed. Results of this pilot study suggest that monthly application of 10 per cent moxidectin/2.5 per cent imidacloprid spot-on may be effective as maintenance therapy in relapsing cases of GD.