Chemical Groups and Actives for Cattle

Cattle parasite treatments

Cattle parasite control requires the use of treatment products for both internal (endo-) and external (ecto-) parasites as part of an integrated parasite management (IPM) program. Products used to control internal parasites (gastro-intestinal nematodes, tapeworms and flukes) may also have a crossover effect on external parasites (ticks, flies, lice and mites). The best parasite control is achieved when a treatment is chosen for best effect against the primary targeted pest. However, it is important to consider the effects this treatment will have on other parasites (as noted on the label) to reduce the build-up of chemical resistance.

Chemical activity

Each parasiticide has a particular chemical compound or ‘active’ component in it. The active operates to disrupt an essential life process in the parasite. Actives within the same chemical group generally have a similar mode of action and target the same life processes. Therefore, if resistance develops to one chemical active in a group this usually confers cross resistance to other chemicals in the same group. Chemical mixtures and combinations incorporate two or more active ingredients; mixtures use multiple actives to target different parasites and chemical combinations use multiple actives to target the same parasite.

Chemical groups for treating cattle against flies

1. Synthetic pyrethroids (SPs): treat flies, ticks and lice
2. Organophosphates (OPs): treat flies, ticks and lice
3. Macrocyclic lactones (MLs): treat flies, roundworms, lice, ticks and mites
4. Chemical mixtures and combinations

Chemical groups for treating premises to kill nuisance flies

1. Synthetic pyrethroids (SPs): treat premises flies
2. Organophosphates (OPs): treat premises flies
3. Insect growth regulators (IGRs): treat premises flies
4. Carbamates: treat premises flies
5. Oxadiazines: treat premises flies
6. Neonicotinoids: treat premises flies
7. Spinosyns: treat premises flies
8. Chemical mixtures and combinations

Chemical groups for treating cattle against ticks

1. Synthetic pyrethroids (SPs): treat ticks, flies and lice
2. Organophosphates (OPs): treat ticks, flies and lice
3. Macrocyclic lactones (MLs): treat ticks, roundworms, lice, flies and mites
4. Insect growth regulators (IGRs): cattle tick and lice
5. Amitraz: treat ticks
6. Chemical mixtures and combinations

Chemical groups for treating cattle against lice and mites

1. Synthetic pyrethroids (SPs): treat lice, flies and ticks
2. Organophosphates (OPs): treat lice, flies and ticks
3. Macrocyclic lactones (MLs): treat lice, mites, roundworms, flies and ticks
4. Insect growth regulators (IGRs): treat lice and cattle tick
5. Rotenone and sulfur: treat lice
6. Chemical mixtures and combinations

Chemical groups for treating cattle against worms

1. Macrocyclic lactones (MLs): treat roundworms, lice, ticks, flies and mites
2. Benzimidazoles (BZs): treat roundworms, tapeworms and liver fluke
3. Imidazothiazole (levamisole): treat roundworms
4. Nitroxynil: treat liver fluke and roundworms
5. Sulfonamide (clorsulon): treat liver fluke
6. Salicylanilide (oxyclozanide): treat liver fluke
7. Amino-acetonitrile derivatives (monepantel): treat roundworms
8. Chemical mixtures and combinations

Chemical actives will vary in their effect on the different parasite groups depending on their formulation and how they are applied. For help in selecting a product to treat specific parasites use this link: