Brand: EXTINOSAD ® Lice, Fly & Maggot Eliminator

Company: ELANCO

FORMULATION: concentrate for topical administration to sheep by dipping, «dipping», «jetting» and «dressing»

ACTIVE INGREDIENT(S): Spinosad: 2.5% = 25 g/L

CHEMICAL CLASS of the active ingredient(s): Spinosyn


PARASITES CONTROLLED (spectrum of activity)

  • Control of body lice Bovicola (Damalinia) ovis on short and long wool sheep.  
  • Control of blowfly strike (Lucilia spp)


* Read the product label for further details on dosing and administration.

Dilution rate: 1:1000 equivalent to 25 ppm (parts per million) = mg/L

For the control of lice in sheep with short wool (2 to 6 weeks after shearing) *

Plunge Dip 40 mL product in 100 L water, equivalent to 10 ppm (parts per million) Prepare replenishment tank with 60 mL product per 100 L water (15 ppm) and constantly add to keep the dip full.

The minimum swim length of the plunge dip should be 9 metres and each sheep's head should be dunked twice (this does not include the initial immersion when entering the dip). Randomly inspect sheep to ensure thorough wetting. To minimise wastage, estimate volume of wash required for day's dipping and mix up accordingly
Shower Dip 80 mL product in 100 L water, equivalent to 20 ppm (parts per million) Prepare replenishment tank with 160 mL product per 100 L water (40 ppm) and constantly add to the sump to keep the sump over 75% full.
Shower dips should only be filled to recommended capacity and run for 12 minutes to ensure thorough wetting (using the top nozzles only for at least 8 minutes). Inspect first 2 loads of sheep to ensure thorough wetting. Do not allow sump level to fall by more than 25%. Pressure requirements: 300-450 kPa (45-60 psi) at 18 L/sec. 

For the control of lice in sheep with long wool (6 weeks to 6 months after shearing)*

Critical Comments: After shearing, sheep should be re-treated with an effective off-shears or short wool product. Reduced effectiveness is likely if used on sheep with lumpy wool.
Jetting Fluid
100 mL product in 100 L water, equivalent to 25 ppm (parts per million) Using jetting equipment, apply 0.5 L of fluid for each month of wool growth (up to 5 litres per sheep) from the poll to the tail base and around the neck and along each side. Ensure saturation to skin level. Pressure requirements 500-700 kPa (75-100 psi).

 For the treatment and prevention of blowfly strike in sheep*

Ceitical Comments: When used on sheep with less than 6 weeks wool a reduced period of protection against blowfly strike may result. A shorter protection period can be expected in lambs and coarse wool (meat breed) sheep. Protection aggainst flystrike lasts 4 to 6 weeks.
Jetting Fluid
100 mL product in 100 L water, equivalent to 25 ppm (parts per million) Using jetting equipment, apply 0.5 L of fluid for each month of wool growth (up to 5 litres per sheep) from the poll to the tail base and around the breech and pizzle as appropriate. Pressure requirements 500-700 kPa (75-100 psi).
Flytrike dressing 5 mL product in 5 L water, equivalent to 25 ppm (parts per million) Prepare a fresh dilution of flystrike dressing each day. Remove the wool from around the wound using clippers or shears. Apply 1 to 2 litres onto the wound.
Mulesing and wound dressing 25 mL product in 5 L water, equivalent to 125 ppm (parts per million) Apply by spraying 40 to 80 mL on to the wound and 25mm into the surrounding wool.

* Use instructions for Australia.


  • LD50 (acute oral) in rats: for the a.i. >4444 mg/kg (source MSDS)
  • LD50 (acute dermal) in rats: for the a.i. >5000 mg/kg (source MSDS)
  • Estimated hazard class according to the WHO: U unlikely to present acute hazard

Withholding periods (=withdrawal times) for meat, milk & wool (country-specific differences may apply: read the product label)

  • Meat:
    • Australia: NIL (ESI NIL; not established for long wool dipping application)
    • New Zealand: NIL
  • Milk for human consumption:
    • Australia: DO NOT USE on ewes which are producing or may in the future produce milk or milk products for human consumption.
    • New Zealand: 35 days
  • Wool:
    • Australia: NIL
    • New Zealand. NIL

WARNING !!!: Never use on humans, dogs or cats.

You may be interested in the following articles in this site dealing with the general safety of veterinary products:


Risk of resistance? LOW.

This means that if this product does not achieve the expected efficacy against the mentioned parasites, it is likely to be due to incorrect use and not to resistance. Incorrect use is the most frequent cause of product failure.

Spinosad, a natural insecticide belonging to the class of the spinosyns was introduced for use against body lice and blowfly strike in Australia in the early 2000s. So far there are no reports on resistance or tolerance of sheep body lice and blowflies to spinosad in Australia or New Zealand. However, other pests have already developed resistance to spinosad (e.g. houseflies) in several countries. And in the past, both body lice and blowflies have developed resistance to several classes of insecticides (e.g. organophosphates, synthetic pyrethroids, benzoylphenyl ureas) in Australia and New Zealand. Consequently it must be assumed that they will sooner or later develop resistance to spinosad as well, particularly if it is uninterruptedly used during years. To delay resistance development Integrated Pest Management (IPM) practices are a must, including product rotation with active ingredients showing mechanisms of action different from that of spinosad.

Alternative chemical classes/active ingredients to prevent resistance of external parasites through product rotation:

These alternative products may not be available in all countries, or may not be available for dipping, jetting or dressing.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?


*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this brand/product is marketed: Australia, New Zealand
GENERIC BRANDS available? NO, not yet in most countries.

Click here to learn more about GENERIC vs. ORIGINAL drugs.

Click here for an overview on the most used antiparasitic BRANDS with concentrates for dipping, spraying, or jetting.


EXTINOSAD Eliminator for Sheep from ELANCO is one of the few products containing spinosad introduced for livestock so far. Spinosad was introduced in crop protection already in the 1990s, but veterinary products were introduced only about a decade later. For the time being there are no livestock products containing spinosad in the US or the EU. 

Spinosad is a natural insecticide obtained from soil bacteria introduced for veterinary use by ELANCO in the 1990s. It is effective against numerous insects pests (e.g. lice, fleas and flies, etc.) and also against ticks and mites. It has no effect whatsoever on internal parasites (roundworms, tapeworms, flukes, etc). It is scarcely used in livestock (so gar only in sheep). It is also used against fleas on dogs and cats, and against poultry mites. It is moderately used in agriculture as well as in domestic and public hygiene.

One of its major benefits is its rapid degradation of spinosad in the environment and the low residues it leaves in animal tissues. Its major weakness for use on livestock is the rather short residual effect after topical administration (against flystrike: 4-6 weeks in Australia, 2-4 weeks in New Zealand).


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional.