Chemical Groups and Actives

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 (roundworms, 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 structure or ‘active’ component. 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 worms

1. Macrocyclic lactones (MLs): treat roundworms, lice, ticks, flies and mites
2. Benzimidazoles (BZs, ‘white drenches’): treat roundworms, tapeworms and liver fluke
3. Imidazothiazole (levamisole, ‘clear drenches’): 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 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

For an overview, see Treating cattle lice: when, how and what chemical group.

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 flies

For an overview, visit Choosing and using products against flies on cattle

1. Synthetic pyrethroids and pyrethrins (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

Premises: internal and external area and surrounds of animal facilities, outbuildings and sheds

For an overview, visit chemical groups and actives against flies at Premises.

1. Synthetic pyrethroids and pyrethrins (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 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 the Paraboss Product Search Tool, which covers all parasites for cattle, sheep and goats: