Efficacy and safety of Felpreva®, a spot-on formulation for cats containing emodepside, praziquantel and tigolaner against experimental infestation with the Australian paralysis tick Ixodes holocyclus

Abstract

The Australian paralysis tick Ixodes holocyclus continues to be a serious threat to companion animals along Australia’s east coast. The tick produces a potent neurotoxin which causes a rapidly ascending flaccid paralysis, which if left untreated, can result in the death of the animal. There is currently only a limited number of products registered in Australia for the treatment and control of paralysis ticks in cats. Felpreva® is an effective spot-on combination containing emodepside, praziquantel and tigolaner. To investigate the therapeutic and long-term persistent efficacy of Felpreva® (2.04% w/v emodepside, 8.14% w/v praziquantel and 9.79% w/v tigolaner) against experimental infestation with I. holocyclus in cats, two studies were undertaken. Fifty cats were included in the studies on study Day -17. These cats were immunized against paralysis tick holocyclotoxin prior to the study commencing. Immunity to holocyclotoxin was confirmed with a tick carrying capacity (TCC) test conducted prior to treatment. Cats were treated once on Day 0. Group 1 cats were treated with the placebo formulation and Group 2 cats were treated with Felpreva®. Cats were infested on Days -14 (tick carrying capacity test), 0, 28, 56, 70, 84 and 91 (weeks 4, 8, 10, 12 and 13). Ticks were counted on cats 24 h, 48 h and 72 ​h post-treatment and infestation, except during the tick carrying capacity test when they were counted approximately 72 ​h post-infestation only. The 24-h and 48-h assessments were conducted without removing the ticks. The ticks were assessed, removed and discarded at the 72-h assessment time-points. Significant differences in total live tick counts at ∼24 h, ∼48 h and ∼72 ​h post-infestation were observed between the treatment and control group. Differences were significant (P ​< ​0.05 to ​< ​0.001) in all instances. Treatment efficacies of 98.1–100% were observed ∼72 ​h post-infestation through to 13 weeks (94 days) post-treatment. These results show that a single application of Felpreva® provides effective treatment and control against induced infestation with paralysis ticks for 13 weeks.