Guidelines for Small Animal Ectoparasiticide Efficacy Submission
Guideline 17
On this page:
Introduction
These guidelines deal with ectoparasiticides on dogs and cats, the major companion animal species in which such products are used.
The parasite species of greatest concern are the common cat flea (Ctenocepllalides felis) and several species of tick of which the paralysis tick (Ixodes holocyclus) and the brown dog tick (Rhipicephalus sanguineous) are of greater importance.
Three classes of small animal flea products exist, viz.:
- those products that kill 100% of fleas at the time of application and which may or may not have a demonstrated protection period during which re-infestation with fleas of treated animals is prevented
- those products generally include shampoos, rinses and powders
- those products that control flea by reducing flea numbers by at least 95% within 3 days of application compared to untreated control animals and which should have a protection period (as described above)
- these products generally include collars, "spot-on" products and sprays
- those products that "aid in the control of fleas" by reducing flea numbers by at least 75% to 95% within 3 days of application compared to untreated control animals, and must have a lower mammalian toxicity than products currently registered products that kill or control fleas are required to show the label statement
"This product is an aid in the control of fleas and may not completely eliminate fleas from treated animals. Total eradication of fleas requires appropriate treatment of both the animal and its environment. A veterinarian should be consulted when flea infestation continues to be a problem."
Although there are other flea species which can infest dogs and cats, Ctenocephalides felis is the most common and can be used as a standard test species. However, attempts should be made to obtain a mixture. Similarly there are a number of tick species capable of infesting small animals but Ixodes holocyclus, because of its clinical importance is accepted as the "indicator" species.
These guidelines therefore use Ctenocephalides felis and Ixodes holocyclus in dogs and/or cats as the relevant test species and hosts respectively. The techniques are transferable with appropriate modification to other host/parasite species. In the absence of Ixodes data, a general tick claim will not be acceptable. The current level of efficacy deemed to be satisfactory is 95%.
Throughout these guidelines details are as much as possible left out so that the applicant can devise the appropriate experimental procedure which will produce significant results. This approach will also allow for differing expert opinion and applicant capabilities to be accommodated. Any departures from the guidelines should be discussed beforehand with the national registration authority.
Data Requirements
Trials should generate data for the following purpose:
- to demonstrate that the minimum dose rate or concentration recommended for use is effective under an identified range of conditions of use (breed, climate, coat type, etc)
- if claimed, to demonstrate what, if any, length of protection against reinfestation by the parasite is provided
- to demonstrate an adequate safety margin and to identify peculiarities of the product - contraindications, side-effects, etc.
The following information should be detailed for each trial:
- location
- date (field trials should be conducted at a time consistent with the usual peak parasite season for the region)
- officer-in-charge and other staff involved product identity
- formulation and batch number
- breed(s) of animals used, ages and sex
- method of housing the animals type of feed
- source of parasite, artificial, natural (degree and continuity of challenge should be assessed in field trials)
- method of application of ectoparasiticide/dose rates/application rates and volumes
- method of assessing flea infestation
- climatic conditions - temperature range, rainfall.
Flea Efficacy
Products for which flea control efficacy is claimed should be tested at the minimum commercial dose rate or concentration in at least 2 pen trials (replicates) and 2 field evaluations at different locations in Australia. Alternatively pen trials with multiple dosage/concentration levels may be used to produce a dose/response curve from which the minimum commercial dose/concentration, and/or positive control groups may also be included if the applicant wishes.
The data may also be supported by other data, eg. in knockdown data for adults and/or larvae.
a) Pen Trials
While results of pen trials undertaken overseas may be used to satisfy the pen trial requirements of this guideline, the applicant should give consideration to confirming these results with Australian pen trial results.
The following requirements are obligatory for pen trials.
- Each treatment group should consist of at least 8 animals.
- All trials should include an untreated control group, consisting of similar numbers as the treated group ie 8 animals.
- Animals should be acclimatised to the trial facility for a minimum of 7 days prior to the commencement of the trial
at least seven days before the commencement of the trial, dogs of uncertain history must be thoroughly bathed using a mild non-insecticidal soap or non-insecticidal shampoo to remove any traces of insecticide from the previous unknown treatment.
- Animals should be individually maintained. If the test compound is suspected to have a vapour component to its action treatment, groups should be sufficiently separated to avoid cross-group action, but similar environmental conditions must be maintained for all groups.
- The following is a suggested pen trial protocol. Other protocols are acceptable if valid scientific arguments support variations.
- Dogs/cats should be inoculated with unfed, adult fleas several times prior to the first treatment to establish a flea population or establish the existing base population on the animals and then load the animals at the commencement of the trial with a known dose of fleas.
- Animals should be ranked by the flea count prior to allocation, then to the treatment or control group so that animals are equally divided between long and short coats, body weight, sex etc.
- The base flea count should be established on day 1, immediately prior to the application of the test insecticide.
Counting post-treatment should be done on a daily basis commencing 24 hours after the treatment application and continued until at least 1 week after the period claimed for protection. In cases where claims of greater than 1 week are concerned animals should be re-challenged with a flea inoculation on at least 4 occasions equally spread up to the time of claimed control.
Flea inoculations should be at least 100 adult fleas/dog and 50 fleas/cat per occasion.
Assessment - each animal should be sedated and placed on a table with good overhead or natural lighting. The whole animal should be examined carefully by an experienced operator. A maximum of 50 fleas are counted
Result recording
- The mean number of fleas counted on untreated dogs should be recorded.
- Percentage reduction in flea numbers in the treatment groups(s) may be calculated from the formula:
R% = 100 (1 - Ta x Cb)
Ca Tb
Where: R = Reduction in parasite population attributable to treatment
Ta = Mean count in treated group post-treatment
Tb = Mean count in treated group pre-treatment
Ca = Mean count in control group post-treatment
Cb = Mean count in control group pre-treatment
The means used are generally arithmetic.
(b) Field Trials
While field trial data from overseas countries can be used to support an application, Australian field trial data is required to substantiate label claims.
Field trials should be conducted in areas with a warm, humid climate where flea pressure is considered moderate to heavy. Trials should include the treatment of the animals belonging to at least 20 to 30 different owners. The owners should be permitted to use the product themselves under supervision following directions developed by the applicant which are considered to be close to the final label
Records of the trial should include:
- actual dose/concentration of product applied by the owner
- parasitological assessment of flea levels by appropriately qualified personnel before treatment and at appropriate intervals after treatment up to the time of claimed control
- owner opinion of product if appropriate.
Parasitological assessment may be done by the following method.
- Hold animal in standing position and run one hand down its back against the lie of the hair so that the skin can be seen, noting the approximate number of fleas on the dorsal aspects of the body, neck and around the ears.
- Repeat this procedure over the left and right sides of the body.
- Stand the animal on its hind legs (or lie it on its back) and examine the ventral abdomen, and axillae plus under the neck and chin, noting the approximate number of fleas.
- Spend a total of 3-4 minutes searching for fleas if they are difficult to find. Record the presence or absence of flea dirt in the coat.
- Assess the level of infestation in accordance with the following scores:
| Score | Total estimate | |
|---|---|---|
| 0 | no fleas seen | |
| 1 | fleas difficult to find | 10 |
| 2 | moderately infested | 10 - 50 |
| 3 | heavily infested | 50+ |
Owner's opinion should be obtained on
- local tolerance
- systemic tolerance, and
- side-effects should be recorded
Acaricide Testing
Australian generated efficacy data will be required. Overseas generated data may be used as supportive evidence.
- There should be at least 8 dogs in each of the control and test groups. The animals have to be isolated from one another.
- At least 5 ticks must become attached to each dog in each control group. These are attached on day 0 and are distributed in as many different parts of the animal's body as possible bearing in mind the natural predisposition to the head and neck.
- On day 1, the animals in the test group have the acaricide applied as required.
- Thorough manual counting and size recording is then carried out on days 2, 3, 4, 5, 6. Ticks are recorded as to viability and size.
- The dogs are again challenged by attaching the original number of ticks at intervals up to the claimed period of control, as per the flea efficacy trials. Sedation is not used for assessments, only for infestations.
- Counting on a daily basis is again carried out and recorded for each dog.
- This procedure is repeated until it is found that the ticks are surviving
for 3 days or more.