WAAVP guideline for myiasis-causing parasites on ruminants

The World Association for the Advancement of Veterinary Parasitology (WAAVP) is a not-for-profit organisation for scientists who study the parasites of non-human animals. The guidelines, developed by the international expert working groups of the WAAVP, assist in the international harmonisation of standards and procedures for the evaluation of veterinary parasiticides. The WAAVP guidelines for evaluating the efficacy of ectoparasiticides on ruminants aim to standardise the minimum set of data that should be submitted to demonstrate the efficacy of new ectoparasiticides for use on or in ruminants.

The APVMA has adopted the WAAVP guidelines for evaluating the efficacy of ectoparasiticides on ruminants to assist registration holders in the conduct of regulatory trials. The APVMA notes that in some instances the WAAVP guidelines advise consultation with the regulator. We also recognise that because of Australia’s unique environmental and geographic parameters, parasite burdens and their population dynamics, farm management practices and animal breeds, there are some differences between the WAAVP guidelines and the APVMA’s recommendations for efficacy trials for products to be registered in Australia. Therefore, applicants should conduct efficacy trials within Australia under typical farm management practices covering relevant geographical regions and the following additional guidance is provided to assist you in conducting these trials. If you follow this additional guidance, your data should generally be sufficient for the APVMA to assess its confidence in the product’s efficacy given Australia’s unique conditions.

This preamble refers to the following World Association for the Advancement of Veterinary Parasitology (WAAVP) guideline: Holdsworth, PA, Vercruysse, J, Rehbein, S, Peter, R, De Bruin, C, Letonja, T & Green, P 2006, ‘World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the efficacy of ectoparasiticides against myiasis causing parasites on ruminants’, Veterinary Parasitology, vol. 136, pp. 15–28.

1. Blowfly species

You should use Lucilia cuprina as the target parasite species for a claim for blowfly strike in your efficacy studies.

2. Field trials

The World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines provide a general recommendation in section 1.3.3.1 that you should select a minimum of two studies in two distinct geographic locations. In section 3.3.2, the WAAVP guidelines provide specific recommendations for field trials with strike flies. The WAAVP guidelines specify that the sponsor must demonstrate that the test product, when used as directed, will be effective for fly strike in a range of geographic environments as well as in animals of different ages, breeds, sexes, wool lengths and so on. The guidelines advise that this will normally involve a minimum of five to10 well-conducted and strategically located regional field studies where adequate fly challenge is demonstrated. The APVMA clarifies and confirms that you should refer to section 3.3.2 for guidance on the numbers of trials, locations and types of animals when you conduct field studies for blowfly strike.

The WAAVP guidelines recommend that you include a negative control group in field trials to demonstrate adequate fly-strike pressure. We consider that as an alternative to including a negative control group in field trials, you may provide daily rainfall data, temperature data, wind speed data and fly-trap records of catches of Lucilia cuprina, and any other data that demonstrate adequate fly pressure. You should also include at least one positive control group (sheep treated with an appropriate registered product) in the field trials in that case. Hearsay by farmers or local advisory people would not be considered acceptable evidence of fly pressure.

3. Fly-strike dressings

When assessing fly-strike dressings as treatments against existing strikes, the World Association for the Advancement of Veterinary Parasitology guidelines recommend that ‘the test product should preferably demonstrate efficacy in killing active, advanced third instar field-derived larvae on sheep, as this is the stage most likely to be detected by farmers’.

We recommend that the test product should demonstrate efficacy in killing active, advanced third instar field-derived larvae on sheep, as this is the stage most likely to be detected by farmers.

4. Wool or hide damage

Given the importance of the wool and cattle by-product industries to Australian commerce, it is recommended that you collect and submit data on wool staining or damage, hide or skin damage, or damage to animal products.

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