Simparica and Simparica TRIO prevent Lyme disease in dogs from ticks

Abstract

BACKGROUND: Both Simparica® and Simparica TRIO® chewable tablets are efficacious within 12 h against existing Ixodes scapularis infestations and within 24 h against re-infestations for 1 month. It is therefore expected that treatment with either product prevents Lyme infections due to their efficacy against I. scapularis ticks before the anticipated transmission of Borrelia burgdorferi by infected ticks. METHODS: In total, four laboratory studies were conducted in which dogs were randomly allocated to two treatment groups of 10 dogs each. On day 0, dogs were either administered a placebo treatment (Pet-Tabs® Palatable Vitamin-Mineral Supplement for Dogs), Simparica TRIO tablets at the minimum dose of 1.2 mg/kg sarolaner, 24 μg/kg moxidectin and 5 mg/kg pyrantel (study 1 and 2) or Simparica at the minimum dose of 2 mg/kg sarolaner (study 3 and 4). On post-treatment day 28, each dog was infested with approximately 50 unfed, wild-caught adult I. scapularis ticks with a high B. burgdorferi infection rate. Blood samples were collected from each prior dog to treatment and on post-treatment days 27, 49, 63, 77, 91 and 104, and qualitatively tested for B. burgdorferi antibodies using the SNAP® 4Dx Plus and Lyme Quant C6® antibody tests. Four skin biopsies from each dog were collected on day 104 from the most common areas of tick attachment and tested by PCR for the quantitative presence of B. burgdorferi. RESULTS: In all studies, at least nine out of 10 placebo-treated dogs were infected with B. burgdorferi before the end of the study. In study 1, one Simparica Trio-treated dog tested positive, whereas in the other studies none of the dogs treated with sarolaner tested positive at any time point during the study. CONCLUSIONS: Both Simparica and Simparica Trio at the minimum label dose prevent the transmission of B. burgdorferi infections as a direct result of killing the I. scapularis vector ticks.