Parasiticidal compositions comprising multiple active agents, methods and uses thereof

A topical veterinary composition for treating or preventing a parasitic infection or infestation in an animal comprising:

• (a) a combination of four active agents comprising,
• i. two contact-acting active agents, wherein one of the contact-acting active agents is fipronil and the other of the contact-acting active agents is an insect growth regulator active agent selected from the group consisting of (S)-methoprene, pyriproxyfen, hydroprene, cyromazine, fluazuron, lufenuron and novaluron;
• and
• ii. two systemically-acting active agents, wherein one of the systemically-acting active agents is praziquantel and the other of the systemically-acting active agents is a macrocyclic lactone active agent selected from the group consisting of eprinomectin, ivermectin, selamectin, milbemectin, milbemycin D, milbemycin oxime and moxidectin;
• (b) a pharmaceutically acceptable carrier comprising dimethylisosorbide and glycerol formal;
• and
• (c) optionally a crystallization inhibitor;
• wherein said composition is a liquid for topical administration;
• wherein fipronil is present in a concentration of about 5 to about 15% (w/v), the insect growth regulator active agent is present in a concentration of about 5 to about 15% (w/v), the macrocyclic lactone active agent is present in a concentration of about 0.01 to about 2% and praziquantel is present in a concentration of about 5 to about 15% (w/v);
• and
• wherein the composition exhibits broad spectrum efficacy against endoparasites and ectoparasites.