The objective of the study was to compare the efficacy of one topical insecticide-acaricide (Frontline Tri-Act ®) and of one collar (Seresto ®) against fleas (Ctenocephalides felis) and ticks (Rhipicephalus sanguineus) on dogs exposed to bi-weekly water showering. Twenty four (24) dogs were enrolled in the study. A first set of 16 dogs were acclimatised to their cages from Day 1 to 7 and a second set of 8 dogs from Day 163 to Day 169. The 24 dogs were randomly allocated to three groups (1 to 3). Dogs assigned to Group 1 were not treated and served as negative controls. Dogs assigned to Group 2 received the Seresto ® collar on Day 0 and dogs in Group 3 received Frontline Tri-Act ® on Days 170 and 198. The dogs were observed hourly for four hours after treatment administration for possible adverse reactions. Dogs in Groups 1 and 2 underwent water showering on Days 14, 28, 42, 56, 70, 84, 98, 112, 126, 143 and 157. Dogs in all groups underwent water showering on Days 173, 185, 199 and 213. Dogs were infested with approximately 100 (±4) adult, unfed C. felis fleas only on Days 177, 190, 203, and 217, in alternance with infestations with 50 adult unfed R. sanguineus on Days 182, 196, 210, and 224, to assess sustained efficacy. Fleas and ticks were removed and counted on 24 and 48 hours ± 2 hours after each infestation, respectively. Frontline Tri-Act ® was >99% effective against C. felis following an initial and a second monthly administration on dogs that were water showered bi-weekly. The Seresto ® collar was from 68.3% to 92.9% effective against C. felis Days 178 to 218 after collar administration. Frontline Tri-Act ® was effective from 87.8% to 100% against ticks whereas Seresto collar was effective from 82.2% to 94.2% from Day 184 to Day 226.
Fleas of the genus Ctenocephalides are the most common ectoparasites of dogs and cats worldwide [
Ticks are among the second most common external parasites of dogs. They have the potential to transmit pathogenic agents to both dogs and their owners. Rhipicephalus sanguineus has a world-wide distribution. It can transmit a variety of pathogens to dogs, including Babesia vogeli, Ehrlichia canis, Anaplasma platys, and Hepatozoon canis. It is also capable of transmitting pathogens to humans such as Rickettsia conorii, the agent of Mediterranean spotted fever [
In that context, the role of an anti-flea and tick product is not only to treat an existing infestation but more importantly, to protect the animal from re-infestation and potential concomitant vector-borne disease transmission or development of allergy [
The aim of the present investigation was to evaluate the long-term flea and tick efficacy of a flumethrin/imidacloprid impregnated collar (Seresto®, Bayer Animal Health) that is applied once compared to the efficacy of the fipronil-permethrin spot on formulation (Frontline Tri-Act®, Boehringer-Ingelheim Animal Health) applied monthly to dogs under experimental conditions mimicking natural water exposure (dogs exposed to bi-monthly water showering).
The study was designed in accordance with the “World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of parasiticides for the treatment, prevention and control of flea and tick infestations on dogs and cats” [
This study was a non-blinded, randomised and negative controlled efficacy study. The study was conducted in three groups of eight dogs each (mongrels and Beagles, males and females), weighing 10 to 27.7 kg. Dogs were included in the study if they had been acclimatised to the study site for at least seven days; they were clinically healthy as verified by a Veterinarian on Day 7 or Day 163; they were ≥6 months old; they weighed ≥ 8 kg on Day 4 or 168; females were not clinically pregnant; they had not been treated with a long acting topical or systemic acaricide/insecticide during the 12 weeks preceding administration day (Day 0 or Day 170).
During the acclimatisation period for Groups 1, 2, and 3, an initial C. felis flea infestation was performed to evaluate the susceptibility of each dog to experimental infestation and for random allocation to the groups.
Dogs assigned to Group 1 were not treated and served as negative controls. Dogs assigned to Group 2 received the Seresto® collar (imidacloprid―flumethrin) on Day 0, and dogs in Group 3 received Frontline Tri-Act® (fipronil―permethrin) on Day 170 and 198. The dose administered was calculated according to the dog’s individual body weight following the European labelling (
Group | Day | Sample size | IVP | Active ingredient (s) | Dose rate |
---|---|---|---|---|---|
2 | 0 | 8 | Seresto® | 4.5% flumethrin and 10.0% imidacloprid (w/w) | One collar per dog weighing ≥ 8 kg |
3 | 170 and 198 | 8 | Frontline Tri-Act® | 6.76% fipronil and 50.48% permethrin (w/v) | 2 mL for dogs weighing 10 kg to 20 kg 4 mL for dogs weighing > 20 kg to 40 kg |
Dogs were infested with 100 (±4) adult unfed C. felis fleas only on Day 7 (dogs enrolled were to be included in Groups 1 and 2) or Day 163 (dogs enrolled were to be included in Groups 3 and 4), for randomisation purposes, and on Days 177, 190, 203 and 217, to assess sustained efficacy. Dogs were also infested by 50 adult unfed R. sanguineus ticks (sex ratio 50:50) on Days 182, 196, 210, and 224. Fleas were removed and counted on Day 6 or Day 164 (24 hours ± 1 hours after infestation) and on Days 178, 191, 204 and 218 (24 hours ± 2 hours after infestation). Ticks were removed and counted 48 hours after each infestation (i.e. Days 184, 198, 212, and 226).
Dogs in Groups 1 and 2 underwent water showering on Days 14, 28, 42, 56, 70, 84, 98, 112, 126, 143 and 157. Dogs in all groups underwent water showering on Days 173, 185, 199 and 213.
Dog with the ID “DF7 98F” (Group 2) managed to remove and destroy its collar and was therefore removed from the study (Day 144) before the end of the study as we could not test anymore insecticidal/acaricidal protection status.
The dog cages were part of an indoor animal unit, environmentally controlled for temperature (20˚C ± 4˚C). A photoperiod of 12 hours light and 12 hours darkness was maintained. The animals were kept individually in cages and no physical contact between dogs was possible. However, animals still had visual and auditory contact with other dogs.
The animals were fed once or twice a day (depending on the age of the dogs) according to the food manufacturer’s recommendation.
Water showering was carried out in a designated area by thoroughly wetting dogs, including the head, with spray from a bathing wand for at least one minute. The dogs were dried with a blow-dryer before being returned to their cages.
The assessment criterion was the number of live ticks and fleas counted in the control and the treated group(s) on the various assessment days.
Laboratory bred strains (European strains) of C. felis and R. sanguineus were used for all infestations. Each dog was infested with approximately 100 (±4) fleas or 50 ticks (25 males and 25 females) on the days as set out in
Fleas were removed and counted by combing technique 24 ± 2 hours after infestation. The method of combing was by several strokes of the comb in each body area of the animal, each time moving in the same direction, following the pattern of the hair coat. Movement, from one part of the animal’s fur to the next, was via strokes overlapping each other, so that no area of fur was missed. After completion of the combing procedure for all body areas, the whole procedure was repeated once more so that all areas were combed a minimum of two times. If fleas were still present, the combing procedure was continued for a third time or more until no live fleas were found. Ticks were removed by thumbing technique of the complete body of each dog. Ticks were categorized as live or dead and attached or free.
Body weights measured during the acclimatisation period, were compared between the groups in order to evaluate their homogeneity at the time of inclusion.
With consideration of available guidelines, EMEA/CVMP/005/2000-Rev.3 [
Efficacy against fleas was calculated according to the following formula:
Efficacy (%) against fleas = 100 × (Mc - Mt)/Mc, where:
Mc = Mean number of live fleas on dogs in the negative control group (Group 1) at a specific time point.
Mt = Mean number of live fleas on dogs in the IVP groups (Group 2 and 3) at a specific.
Efficacy against ticks was calculated as follows:
Efficacy (%) against ticks = 100 × (Mc - Mt)/Mc, where:
Mc = Mean number of live ticks on dogs in the negative control group (Group 1) at a specific time point.
Mt = Mean number of live ticks on dogs in the IVP groups (Group 2 and 3) at a specific time point.
The groups were compared using ANOVA Test. Groups were homogeneous with regard to flea counts measured during the acclimatisation period. The level of significance of the formal tests was set at 5%, all tests were two sided.
No adverse reactions that could be related to any of the treatment were observed during the 8 month study period. Arithmetic mean values of live C. felis flea counts, efficacies, and p-values, are summarised in
Control Group 1 | Group 2 | Group 3 | |||
---|---|---|---|---|---|
Day | Mean +/− SD | Mean +/− SD | Percentage efficacy | Mean +/− SD | Percentage efficacy |
Day 178 | 70.4 +/− 11 | 22.3 +/− 13.2 | 68.3 | 0.0 +/− 0 | 100 |
Day 191 | 81.0 +/− 10.8 | 5.7 +/− 4.3 | 92.9 | 0.8 +/− 2.7 | 99.1 |
Day 204 | 79.9 +/− 10.1 | 8.7 +/− 4.6 | 89.1 | 0.0 +/− 0 | 100 |
Day 218 | 76.0 +/− 8.6 | 15.4 +/− 10.4 | 79.7 | 0.0 +/− 0 | 100 |
Group 1: Negative control; Group 2: Dogs were treated with Seresto® collar; Group 3: Dogs were treated topically with Frontline Tri-Act®; SD = Standard Deviation.
ANOVA p-value | ||||
---|---|---|---|---|
Comparison | Day 178 | Day 191 | Day 204 | Day 218 |
Group 1 with Group 2 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Group 1 with Group 3 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Group 2 with Group 3 | 0.00055 | 0.022 | 0.0021 | 0.00055 |
p-value: Wilcoxon rank sum test with continuity correction; Alternative :two. Sided; Group 1: Negative control; Group 2: Dogs treated with Seresto® collar; Group 3: Dogs treated topically with Frontline Tri-Act®; SD = Standard Deviation.
Control Group 1 | Group 2 | Group 3 | |||
---|---|---|---|---|---|
Day | Mean +/− SD | Mean +/− SD | Percentage efficacy | Mean +/− SD | Percentage efficacy |
Day 172 | 34.1 +/− 5.6 | 3.6 +/− 3.1 | 89.5 | 7.0 +/− 5.8 | 79.5 |
Day 184 | 26.1 +/− 7.2 | 2.4 +/− 2.1 | 90.7 | 0.5 +/− 0.9 | 98.1 |
Day 198 | 33.8 +/− 7.9 | 6.0 +/− 5.1 | 82.2 | 4.1 +/− 4 | 87.8 |
Day 212 | 33.3 +/− 6.5 | 3.4 +/− 1 | 89.7 | 0.0 +/− 0 | 100 |
Day 226 | 32.3 +/− 8.5 | 1.9 +/− 1.9 | 94.2 | 1.4 +/− 2.6 | 95.7 |
Group 1: Negative control; Group 2: Dogs treated with Seresto® collar; Group 3: Dogs treated topically with Frontline Tri-Act®.
ANOVA p-value | |||||
---|---|---|---|---|---|
Comparison | Day 172 | Day 184 | Day 198 | Day 212 | Day 226 |
Group 1 with Group 2 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Group 1 with Group 3 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Group 2 with Group 3 | 0.3493 | 0.3923 | 0.5135 | 0.0595 | 0.8397 |
p-value: One-way ANOVA with a treatment effect; Group 1: Negative control; Group 2: Dogs treated with Seresto®collar; Group 3: Dogs treated topically with Frontline Tri-Act®.
50% of the challenge) was demonstrated for all dogs in the negative control group at each assessment time point. The infestation rate for ticks ranged from 26 to 30 in control dogs, also confirming an adequate tick challenge.
Based on arithmetic mean values of flea and tick counts, significantly fewer fleas and ticks were recorded for the treated groups compared to the negative control group throughout the study (p < 0.05).
Statistically significantly fewer fleas were present on the dogs treated with Frontline Tri-Act® than the dogs treated with the Seresto® collar (p < 0.05) on all time-points. There was not significant difference between the two treated groups in regard to the tick counts at any time-points.
Based on arithmetic mean values of live flea counts, the Seresto® collar was 68.3% to 92.9% effective against C. felis from 178 to 218 days after collar administration.
Based on arithmetic mean values of live fleas, Frontline Tri-Act® was 99.1% to 100% effective against C. felis after two monthly administrations, despite fortnightly water showering. Frontline Tri-Act® was persistently ≥95% effective against C. felis following monthly administration based on arithmetic mean values for live fleas. Based on arithmetic means, Frontline Tri-Act® efficacy ranged from 87.8% to 100% against ticks whereas Seresto collar had efficacy ranging from 82.2% to 94.2% from Day 184 to Day 226.
This study demonstrated the efficacy of monthly applications of the fipronil-permethrin combination product in the control of both flea and tick infestations in dogs subjected to simulated rain or water immersion. Two successive monthly treatments provided a sustained flea efficacy of >99%, and a tick efficacy > 87.8%. Following a monthly schedule of application, the spot on product was significantly more effective against C. felis on dogs exposed to simulated rainfall twice a month than the flumethrin/imidacloprid impregnated collar in its 7th and 8th month, including water showering twice every month during 8 months. No significant differences were observed in regard to tick efficacy.
Collars are often considered as inexpensive devices for the prevention of ectoparasite infestations due to their long lasting activity, i.e., several months of sustained activity. This persistant activity is due to the slow release of the actives from the matrix of the collar [
In previous studies, flumethrin/imidacloprid impregnated collars demonstrated 93.2% efficacy on Day 177 (6 months) and 94.5% on Day 191 against fleas under experimental conditions without water exposure [
It can be concluded from this study that water immersion is an important factor to be considered when assessing the efficacy of an ectoparasiticide in the field. Indeed, animals exposed to parasitic pressure usually have an outdoor lifestyle and are therefore often subjected to natural conditions including rain, swimming and bathing [
The work reported herein was funded by Boehringer Ingelheim Animal Health. All authors are current employees or contractors.
This document is provided for scientific purposes only. Any reference to a brand or trademark herein is for informational purposes only and is not intended for a commercial purpose or to dilute the rights of the respective owner(s) of the brand(s) or trademark(s).
Beugnet, F., Servonnet, M., Halos, L. and Lebon, W. (2018) Comparative Efficacy of Frontline Tri-Act® Spot on (Fipronil/Permethrin) versus Seresto® Collar (Imidacloprid/Flumethrin) against Fleas (Ctenocephalides felis) and Ticks (Rhipicephalus sanguineus) on Dogs with Simulation of Bi-Monthly Rain Exposure. Open Journal of Veterinary Medicine, 8, 65-74. https://doi.org/10.4236/ojvm.2018.85008