Compositions comprising an aryl pyrazole and a substituted imidazole, methods and uses thereof

A veterinary formulation for treating or preventing a parasitic infestation in an animal comprising:

• (a) a 1-aryl-5-alkyl or 5-haloalkylpyrazole of formula (IB) or a veterinarily acceptable salt thereof,
• wherein:
• R1b is alkyl, CN or halogen;
• R2b is S(O)6R14b or 4,5-dicyanoimidazol-2-yl or haloalkyl;
• R14b is alkyl or haloalkyl;
• R3b is a hydrogen, halogen, —NR7bR8b, —S(O)mR9b, —C(O)R9b, —C(O)OR9b, alkyl, haloalkyl, —OR10b or an —N═C(R11b) (R12b);
• R6b is a halogen, haloalkyl, haloalkoxy, S(O)qCF3 or SF5 group;
• R7B and R8B independently represent a hydrogen, alkyl, haloalkyl, —C(O)alkyl, —S(O)rCF3, acyl or alkoxycarbonyl;
• or
• R7b and R8b can together form a divalent alkylene radical which is optionally interrupted by one or two divalent heteroatoms;
• R9b is an alkyl or haloalkyl;
• R10b is hydrogen, alkyl or haloalkyl;
• R11b is hydrogen or alkyl radical;
• R12b is an optionally substituted aryl or an optionally substituted heteroaryl group;
• R4b and R13b represent, independently of one another, hydrogen, halogen CN or NO2;
• m, n, q and r represent, independently of one another, an integer equal to 0, 1 or 2;
• and
• Z represents a trivalent nitrogen atom or a C—R13b radical, the three other valencies of the Carbon atom forming part of the aromatic ring;
• (b) a substituted imidazole compound of formula (II),
• wherein
• X1 is H, Cl, or CH3;
• X2 and X8 are H;
• X3 is H, F, —OCH3, Cl, I, —OCHF3 , —OCF3 , NH2 , CHCH2 , CHCHCH3, CCH, CCCH3, C2H5 or CH3;
• X4, X5, X6 and X7 are H or CH3;
• (c) a veterinarily acceptable carrier;
• and
• (d) optionally a crystallization inhibitor.