Brand: IO TICK OFF Pour-on Tick Development Inhibitor


FORMULATION: «pour-on» for topical administration. To be applied in two 7cm wide bands, either side of the spine from shoulder to tail.

ACTIVE INGREDIENT(S): fluazuron: 25 mg/mL (=2.5%)

CHEMICAL CLASS of the active ingredient(s): benzoylphenyl urea - tick development inhibitor


PARASITES CONTROLLED* (spectrum of activity)

* Country-specific differences may apply: read the product label.

  • Cattle ticks = Rhipicephalus (Boophilus) microplus.
  • Protection of up to 12 weeks against re-infestation


  • Cattle: 1.5 mg/kg bw, equivalent to 6 ml/100 kg bw
Body weight (kg) Total dose (mL) Vol. per treatment band (mL) Number of bands
101-150 9 4.5 2
151-200 12 6.0 2
201-250 15 7.5 2
251-300 18 9.0 2
301-350 21 10.5 2
351-400 24 12.0 2
401-450 27 13.5 2
451-500 30 15.0 2
501-550 33 16.5 2
551-600 36 18 2
601-650 39 19.5 2
>650 3 mL/50 kg 1.5 mL/50 kg 2

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


  • LD50 (acute oral) in rats: >2000 mg/kg
  • LD50 (acute dermal) in rats: >2000 mg/kg
  • Estimated hazard class according to the WHO: not listed

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

  • Meat: 42 days (ESI: 42 days). Calves that have suckled on treated cows must not be slaughtered less than 4 months since the last treatment of the cows.
  • Milk: not approved.

WARNING !!!: Never use on humans, dogs and cats

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


Risk of resistance? LOW

Resistance of cattle ticks to fluazuron was reported first in 2010 in two properties in Queensland. In laboratory tests on engorged adult ticks of these properties the concentration of fluazuron required for inhibiting larval hatching out of the laid eggs was 20x higher than for susceptible ticks (Resistance Ratio =20). However, to our knowledge no subsequent confirmation or otherwise characterization of these resistant ticks has been published so far.

In 2014 another publication reported the first case of low-level fluazuron-resistant cattle ticks in one property in Brazil. These ticks (Jaguar strain) were found to be simultaneously resistant to six chemical classes: besides benzoylphenyl ureas (fluazuron) they showed different degrees of resistance to organophosphates (chlorpyrifos), synthetic pyrethroids (cypermethrin), amidines (amitraz), phenylpyrazoles (fipronil) and macrocyclic lactones (ivermectin).

Although the situation is not yet dramatic, these cases are a warning. Considering the very strong and increasing reliance on fluazuron and macrocyclic lactones (doramectin, ivermectin, moxidectin, etc.) for cattle tick control in many regions, development and spreading of resistance to these two chemical classes is only a matter of time, unless serious measures are taken to prevent it.

Alternative chemical classes/active ingredients to prevent fluazuron-resistance of cattle ticks through product rotation:

These alternative products may not be available in all countries, or may not be available as pour-ons.

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 (maybe under another TM): Australia
GENERIC BRANDS available? YES, Several ones. This product is itself a local generic version of ACATAK Pour-on.

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

For an overview on the most used antiparasitic pour-on brands click here.


IO TICK OFF Pour-on Tick Development Inhibitor is a generic version of ACATAK Pour-on, the first and original brand with fluazuron introduced in the 1990s by CIBA-GEIGY (later NOVARTIS → ELANCO).

Fluazuron is a benzoylphenyl-urea tick development inhibitor introduced in the 1990s (by CIBA-GEIGY → NOVARTIS → ELANCO). It is moderately used in cattle but not at all in other livestock, pets or agriculture.

Fluazuron has a systemic mode of action. This means that it reaches the ticks through the blood of the host. After topical administration, the active ingredient reaches the bloodstream of the host either through the skin (transdermally) or through ingestion (mainly through licking). Being very lipophilic, it is deposited in the body fat of cattle for weeks, from where it is slowly released back to the blood and is excreted. Ticks (adults, larvae and nymphs) that feed blood on cattle ingest fluazuron with their blood meal. As a consequence eggs laid by female ticks won't hatch, and larvae and nymphs will die when they attemp molting.

Being a tick development inhibitor fluazuron does not kill the ticks immediately, i.e. it has no knockdown effect. For this reason fluazuron is not primarily appropriate for treating established tick infestations (curative of therapeutic use): it will take 2-3 weeks for cattle to become tick free. Instead fluazuron is highly effective as a tick preventative when used strategically. Strategic use means treating all cattle in a property before the onset of the tick season, i.e. usually in early to mid spring, and to re-treat them at the recommended interval, usually when first ticks are seen again on cattle. Treatment in spring ensures that most tick larvae of the first generation that infect cattle won't survive and reproduce, which strongly decimates the tick population. These effect results in a strong population control in the property, provided all cattle are treated. If only part of the cattle are treated, the effect on the tick population will be weaker. Used this way 3 and sometimes only 2 treatments may be sufficient to protect cattle against cattle ticks during the whole tick season.

Fluazuron is partially excreted through the milk in lactating cows. As a consequence calves sucking milk from treated mother cows get enough fluazuron to be protected against ticks for weeks: they don't need to be treated. However protection of lactating mother cows is shorter than in non-lactating animals, because the administered dose is excreted faster in these cows than in non-lactating cattle.

Used at the recommended dose, the length of protection of cattle against re-infestation (i.e the residual effect) depends mainly on three major factors: breed, lactation and tick pressure. Protection on non-lactating pure Zebu cattle breeds (Bos indicus) can easily last more than 12 weeks. Protection on non-lactating European breeds (Bos taurus) is usually around 10 weeks. Protection on crossbred cattle is somewhere in between. The difference is explained by the natural resistance of Zebu cattle to ticks. It is known that survival of cattle ticks on Zebu cattle is about 15 times lower than on European breeds.

Protection on lactating cows may be 4 to 6 weeks shorter than in non-lactating cows, depending on milk production. The higher the amount of milk produced, the shorter the protection.

The effect of tick pressure affects both efficacy as well as length of protection. No product, including ACATAK achieves 100% control. Therefore the more ticks infest a property (=tick pressure), the more ticks will infest cattle grazing there.

Tick control on cattle is a complex business. To ensure best use of this and other products against the cattle tick Rhipicephalus (Boophilus) microplus we strongly recommend you to read the specific article on these ticks in this site (click here).


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