methoprene and Tick-Infestations

For their biological and ecological characteristics, ticks are vectors of the widest variety of pathogens causing tick-borne diseases (TBDs). Little information is available about the ways in which time spent by ticks to feed on hosts, transmission times and TBD prevention are related and it is exclusively limited to laboratory reports on adult stages. In particular, the time required by immature stages to transmit pathogens has not been determined for most TBDs. Considering their importance for animal and human health, effective control of immature ticks is advisable to reduce the damage ticks cause. Recently, the efficacy of a combination of imidacloprid 10%/permethrin 50% was compared with that of fipronil 10%/S-methoprene 9% against ticks when administered to naturally infected dogs. A semi-quantitative method was used to assess the methodological parameters to calculate drug efficacy on immature stages. On adult ticks, the efficacy of both products was high and overall very similar, whereas for the immature stages the combination of imidacloprid 10% and permethrin 50% had a higher efficacy than fipronil 10% and methoprene 9% throughout the observation period (statistically significant difference on day + 28 only). The semi-quantitative method proposed for the evaluation of immature stages can be considered a useful tool for calculating the efficacy of a drug in the field. Due the important role of immatures in the spread of TBDs, the immature tick load should be calculated to assess the efficacy of acaricidal products both under laboratory and field conditions.

Topics: Animals; Bites and Stings; Dog Diseases; Dogs; Drug Combinations; Drug Evaluation; Female; Imidazoles; Insecticides; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Rhipicephalus sanguineus; Tick Infestations; Tick-Borne Diseases; Ticks; Time Factors

Five laboratory studies were conducted to confirm that a single topical dose of the novel combination of fipronil, amitraz and (S)-methoprene, CERTIFECT™ (Merial Limited, GA, USA), is efficacious for the rapid control of pre-existing infestations and the prevention of new infestations with Ixodes scapularis, Dermacentor variabilis, Amblyomma americanum and Amblyomma maculatum for at least 28 days on dogs. In each study, 8 male and 8 female purpose-bred, laboratory beagles were randomly assigned to one of two study groups (treated and untreated). Starting on the day before treatment, each dog was infested weekly with about 30 or 50 ticks, depending on the study. Treatment with the novel combination rapidly eliminated pre-existing infestations and controlled weekly re-infestations for at least 28 days. Pre-existing infestations with all four tick species were rapidly and effectively reduced, with post-treatment therapeutic efficacies ranging from 91.7 to 99.5% within 18-48 h post treatment. Amblyomma maculatum numbers were significantly (p<0.05) reduced on treated dogs from the first tick counts as early as 6h post-treatment. All subsequent infestations with each of the 4 tick species were quickly disrupted, with prophylactic efficacies greater than 90% within 18-48 h post-infestation for at least a full month. Because the combination of fipronil, amitraz and (S)-methoprene quickly starts disrupting and killing ixodid ticks within hours of treatment, with similar high levels of efficacy maintained for at least 28 days in these and other studies, the authors conclude that a single topical treatment with CERTIFECT may prevent the transmission of most infectious agents carried by ixodid ticks for at least one month.

Topics: Administration, Topical; Animals; Dog Diseases; Dogs; Double-Blind Method; Drug Combinations; Female; Insecticides; Ixodidae; Male; Methoprene; Pyrazoles; Tick Control; Tick Infestations; Time Factors; Toluidines; Treatment Outcome; United States

Four studies were conducted to show the effectiveness of a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT™, Merial Limited, GA, USA) for the therapeutic and preventive control of Ixodid tick species affecting dogs in Europe: Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus. In each, untreated control dogs were compared to others treated with the novel combination. All dogs were infested with 50 adult, unfed ticks prior to treatment and at 7-day intervals after treatment. Ticks on all dogs were counted at 18, 24 and 48 h after treatment (therapeutic efficacy) or infestation (preventive efficacy). Therapeutic efficacy of fipronil, amitraz and (S)-methoprene was excellent as shown by significant (p<0.05) and greater than 97% and up to 100% reductions in the 48 h tick counts and significant (p<0.05) detachment/death of ticks evident at 18-24h after treatment for all three tick species. Preventive efficacy was demonstrated by significant (p<0.05) and greater than 93% and up to 100% reductions in tick counts at 48 h after repeat infestations out to 35 days after treatment for I. ricinus and out to 42 days after treatment for D. reticulatus and R. sanguineus. The time to substantial disruption of establishment of new tick infestations after treatment was less than 18-24h and was maintained for up to 28 days after treatment of I. ricinus and D. reticulatus infestations, and 4h to at most 18 h and maintained up to 35 days after treatment of R. sanguineus. Similar preventive efficacy profiles for each of the Ixodid species tested suggest that CERTIFECT kills all Ixodid species starting 4h after contact as demonstrated for R. sanguineus.

Topics: Administration, Topical; Animals; Dermacentor; Dog Diseases; Dogs; Double-Blind Method; Drug Combinations; Europe; Female; Insecticides; Ixodes; Male; Methoprene; Pyrazoles; Rhipicephalus sanguineus; Tick Control; Tick Infestations; Toluidines; Treatment Outcome

Healthy, purpose-bred laboratory beagle dogs that had not been exposed to ticks and were seronegative for Borrelia burgdorferi and Anaplasma phagocytophilum were randomly assigned to four groups of eight dogs each. Control group 1 was not treated. Groups 2, 3 and 4 were treated with a single topical application of a new formulation of fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) at 28, 21 or 14 days prior to tick infestation, respectively. Each dog was infested with 25 female and 25 male field-collected adult Ixodes scapularis ticks that had infection rates of 66% for B. burgdorferi sensu stricto and 23% for A. phagocytophilum, as determined by polymerase chain reaction. Two and five days after tick infestation, control dogs had an average of 9.5 and 13.9 attached adult female ticks, respectively, whilst the 24 treated dogs remained tick-free aside from a single tick on the 2nd day after infestation. Serial serological tests demonstrated that the ticks successfully infected 8/8 control dogs with B. burgdorferi and co-infected 6/8 with A. phagocytophilum. B. burgdorferi infection also was confirmed in most control dogs by culture (6/8) and PCR (7/8) of skin biopsies. In contrast, CERTIFECT protected all 24 treated dogs against infection by both B. burgdorferi and A. phagocytophilum, as demonstrated by their negative serological tests throughout the study and the absence of any positive skin biopsy culture or PCR in these dogs.

Topics: Administration, Topical; Anaplasma phagocytophilum; Animals; Antibodies, Bacterial; Arachnid Vectors; Borrelia burgdorferi; Dog Diseases; Dogs; Double-Blind Method; Drug Combinations; Ehrlichiosis; Female; Insecticides; Ixodes; Lyme Disease; Male; Methoprene; Pyrazoles; Rhode Island; Tick Control; Tick Infestations; Time Factors; Toluidines

Four groups of seven dogs were treated topically with a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT™, Merial Limited, GA, USA) on 28, 21, 14 and 7 days prior to tick infestation, respectively and acaricidal efficacy and transmission blocking compared with an untreated control group (seven dogs). All dogs were infested with adult Dermacentor reticulatus ticks harbouring Babesia canis canis. Babesia canis canis was transmitted by D. reticulatus to all seven untreated control dogs, confirmed following demonstration of clinical signs, by the detection of B. canis parasites in thin blood smears and B. canis canis PCR-RLB DNA assay on blood and the development of B. canis canis antibody titres by 14-21 days after tick infestation. The majority of treated dogs remained sero-negative for 42 days after infestation. Therefore, the treatment of dogs with CERTIFECT applied up to 28 days prior to infestation with D. reticulatus harbouring B. canis canis, successfully prevented the development of clinical signs of canine babesiosis.

Topics: Administration, Topical; Animals; Arachnid Vectors; Babesia; Babesiosis; Dermacentor; Dog Diseases; Dogs; Double-Blind Method; Drug Combinations; Europe; Female; Insecticides; Male; Methoprene; Pyrazoles; Tick Control; Tick Infestations; Time Factors; Toluidines

The sustained speed of kill against Dermacentor reticulatus of two topical combinations, one containing fipronil/amitraz/(S)-methoprene and the other, imidacloprid/permethrin, was evaluated in dogs. Two treated groups and one untreated control group of eight adult Beagle dogs each were randomly formed based on pre-infestation rates and bodyweight. Each treatment was administered topically once on Day 0, according to the recommended label dose and instructions for use. All dogs were infested with 50 adult unfed D. reticulatus starting on Day 1, then weekly, for a total of five weeks. While most studies determine tick efficacy at 48 hours (h), in this study, all remaining ticks were counted and categorized 24 h following each infestation. The numbers of ticks (living or dead) that remained attached on treated dogs were compared to those on the control animals. The percent reduction of attached ticks (disruption of attachment) at 24 h on dogs treated with fipronil/amitraz/(S)-methoprene remained above 92% for four weeks. The reduction of attached ticks at 24 h on dogs treated with imidacloprid/permethrin did not reach 80% during the entire study. The number of ticks attached at 24 h was significantly (p<0.05) lower in the fipronil/amitraz/(S)-methoprene group than in the imidacloprid/permethrin group in assessments on Days 2, 15, 22, 29 and 36. When assessing efficacy based upon live ticks on treated versus control dogs, fipronil/amitraz/(S)-methoprene 24 h efficacy was above 95% for four weeks, decreasing to 77.8% at Day 36. The 24 h efficacy of imidacloprid/permethrin ranged from 56.2% to 86.7% through Day 29, never achieving 90% throughout the study. The 24-hour efficacy of fipronil/amitraz/(S)-methoprene was significantly (p<0.05) higher than imidacloprid/permethrin at all time points, including Day 36.

Topics: Animals; Antiparasitic Agents; Dermacentor; Dog Diseases; Dogs; Drug Combinations; Imidazoles; Insecticides; Juvenile Hormones; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Single-Blind Method; Tick Infestations; Time Factors; Toluidines

This field trial was designed to test the efficacy, in terms of treatment and prevention, of the fipronil 10%+(S)-methoprene 9% combination against immature and adult stages of Rhipicephalus sanguineus in naturally infested dogs, and to assess the effect of a single plain water exposure. Twenty-four dogs of various age, sex, weight and coat length were divided into two homogeneous groups, treated (T) and control (C), and housed into twin outdoor kennels. Trial baseline was designed as day 0, when dogs from group T were treated with a commercial spot-on formulation of fipronil 10%+(S)-methoprene 9%, while subjects from group C were left untreated and served as control. After treatment, tick load for each included dog was estimated, for both adult and immature ticks, using the localization and count over the entire body surface at the following time-points: day 2, to evaluate the speed of kill and at days 7, 14, 21 and 28 to assess the persistence of efficacy. The effect of water exposure on the product efficacy was tested at day 14 of the study, when six dogs, homogenously selected from group T, were soaked through with plain water. The overall tick load in dogs from group C was high throughout the entire study period, ranging from 103.2 (day 28) to 161.3 (day 0), and confirmed the high tick pressure. Speed of kill calculated at 48 h post-treatment was slightly higher for adult ticks (96.2%) than for immature stages (91.6%). Compared to the control, dogs treated with the fipronil+(S)-methoprene maintained a significantly lower mean tick load for both adult and immature stages in the four weeks of observation. Persistence of efficacy against immature stages ranged from 97.1% the first week, 99.6% second week, 99.7 third week and 93.1% in the last week. In the same way, efficacy against adult ticks was constantly high, shifting from 94.5% to 92.5%. Overall efficacy (adults+immatures) was the strongest in the first two weeks (i.e., 96.1% and 96.6%) and lowered in the two remaining weeks (i.e., 94.2% and 93.4%). Results showed that water exposure did not affect the activity and persistence of the tested combination. On the basis of this field trial, the fipronil+(S)-methoprene combination represents a highly efficacious product to control all stages of R. sanguineus ticks on dogs.

Topics: Administration, Topical; Animals; Dog Diseases; Dogs; Double-Blind Method; Drug Combinations; Female; Insecticides; Male; Methoprene; Pyrazoles; Rhipicephalus sanguineus; Tick Infestations

This study evaluated overall efficacy, percentage of dogs free of live ticks, retention of ticks, and efficacy against retained ticks of fipronil (9.8% w/w) + (S)-methoprene (8.8% w/w) and imidacloprid (8.8% w/w) + permethrin (44% w/w) spot-on topical solutions against Dermacentor variabilis-infested dogs. Tick control was significantly greater (P < .05) on dogs treated with fipronil + (S)-methoprene than on control dogs for the entire 30-day study period. Conversely, the combination product of imidacloprid + permethrin demonstrated activity significantly (P < .05) different from that seen on control dogs only up to day 23. Significantly (P < .05) more dogs treated with fipronil + (S)-methoprene were free of live ticks compared with controls on days 3, 9, and 16. There was never a significant difference (P > .05) between control and imidacloprid + permethrin-treated dogs in numbers of dogs free of live ticks. After the initial 10-minute tick exposure, lower numbers of ticks were retained on the imidacloprid + permethrin-treated dogs than on the fipronil + (S)-methoprene-treated dogs. However, when evaluating the effectiveness of the acaricides on "retained ticks," it appears that while some of the ticks were rapidly knocked down on the imidacloprid + permethrin-treated dogs, efficacy against ticks still retained at 10 minutes was never greater than 50%.

Topics: Animals; Dermacentor; Dog Diseases; Dogs; Drug Combinations; Female; Imidazoles; Insecticides; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Tick Infestations

Preventing tick bites is a fundamental step towards reducing the impact of tick-borne protozoal, bacterial and viral diseases (TBDs) in humans and animals. The aim of this study was to evaluate the efficacy of a combination of imidacloprid 10%/permethrin 50% and of fipronil 10%/S-methoprene 12% against ticks in naturally infected dogs and to assess methodological parameters to calculate drug efficacy on tick immature stages. From July to August 2004, 45 privately owned dogs of various sexes, ages, breeds, coat length and habits were enrolled in a trial carried out in an area (radius approximately 50km) in Southern Italy. Three homogeneous groups (both for dog population and tick population) were formed: 15 dogs treated with imidacloprid 10% and permethrin 50% spot-on (group A), 15 dogs treated with fipronil 10% and methoprene 12% spot-on (group B) and 15 untreated dogs (group C). The dogs in each group were then sub-grouped according to their age and weight. Two different treatments were administered (time 0 and +28 days) to groups A and B, and the dogs were checked weekly for tick infestation until day +56 post-treatment (p.t.). Twenty-four areas distributed on the whole body surface were examined for ticks at each follow-up, while only at time 0 and at day +56 p.t., ticks were collected from the dogs and identified. For the immature stages a semi-quantitative method was adopted and the load of immature stages was evaluated and grouped into four classes up to day +56 p.t. when the mean number of immature ticks (MIT) for each infection class was evaluated. All the adult ticks collected were identified as brown dog ticks (Rhipicephalus sanguineus). Immature stages were first compared at day +28 p.t.. The efficacy of both products used in groups A and B on adult ticks was high and generally very similar. Conversely, the efficacy of imidacloprid 10% and permethrin 50% against immatures was higher than that of fipronil 10% and methoprene 12% throughout the observation period with statistically significant differences (p<0.05) at day +28 p.t. (i.e. group A=98.52%, group B=72.40%). On the whole, in analysing the efficacy of both products against adult plus immature ticks, it was found that the combination of imidacloprid 10% and permethrin 50% was more effective than fipronil 10% and methoprene 12%, with the differences being statistically significant at day +28 p.t. (group A=98.43%, group B=77.56%).

Topics: Animals; Dog Diseases; Dogs; Drug Combinations; Female; Imidazoles; Insecticides; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Tick Infestations; Ticks

Haemaphysalis longicornis is one of the most important ticks infesting a wide range of mammals including dogs in Japan. H. longicornis is recorded to be a vector of, for example, Babesia gibsoni. It was the aim of the study presented here to evaluate the efficacy of imidacloprid/permethrin and fipronil/(S)-methoprene against larval, nymphal and adult stages of H. longicornis under in vitro as well as in vivo conditions. In the in vitro part of the study, ticks showed avoidance behaviour to imidacloprid/permethrin-treated filter papers. The onset of acaricidal efficacy in the imidacloprid/permethrin group was recorded earlier than in the fipronil/(S)-methoprene group. In the in vivo experiment three beagles per group were treated with either imidacloprid/permethrin, fipronil/(S)-methoprene or left untreated. Each dog was infested with 30 adult female H. longicornis. Ticks were place on a shaved area of skin of the treated dogs and behaviour of the ticks was recorded as before. After 3 h all ticks were removed and placed in Petri dishes. Ticks were further examined until day 4 post-treatment (p.t.). All ticks recovered from the untreated dogs survived. At 4 h p.t. (1 h post-removal) 40 of the 90 ticks exposed to the imidacloprid/permethrin treatment and 25 of the 90 ticks in the fipronil/(S)-methoprene-treated group were found dead. At day 1 p.t., 61 ticks in the imidacloprid/permethrin- and 81 ticks in the fipronil/(S)-methoprene-treated group were recorded dead. At the final examination day 4 p.t., all 90 ticks were found dead in the imidacloprid/permethrin group, while five ticks remained alive in the fipronil/(S)-methoprene group.

Topics: Administration, Topical; Animals; Cholinesterase Reactivators; Dog Diseases; Dogs; Drug Therapy, Combination; Female; Imidazoles; Ixodidae; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Tick Infestations

This study compared the efficacy of two of the most widely veterinary-dispensed topical products for control of ticks on dogs: fipronil-(S)-methoprene and imidacloprid-permethrin. Eighteen healthy beagle dogs of both sexes were divided into three groups of six dogs. Group 1 served as the untreated control. Dogs in group 2 were treated with fipronil 10% + (S)-methoprene 9% w/v applied once on day 0, and those in group 3 were treated with imidacloprid 8.8% and permethrin 44% w/v, applied once on day 0. All dogs were infested with approximately 50 unfed Dermacentor reticulatus ticks on days 1, 7, 14, 21, 28, 35, and 42, and ticks remaining were counted and removed 48 hours after each infestation. The 48-hour efficacy of the fipronil-(S)-methoprene combination remained at 100% at all assessment points through and including day 37, declining to 95.30% on day 44. The 48-hour efficacy of the imidacloprid-permethrin combination peaked at 86.46% on day 9, decreased to 73.37% by the third week, and fell to 63.53% by the end of the study (day 44). Significantly (P < .05) fewer ticks were recovered from dogs treated with fipronil-(S)-methoprene or imidacloprid-permethrin than from untreated control dogs at each infestation. Notably, the dogs treated with fipronil-(S)-methoprene had significantly (P < .05) lower tick counts at every assessment than the dogs treated with imidacloprid-permethrin.

Topics: Administration, Topical; Animals; Dermacentor; Dog Diseases; Dogs; Drug Therapy, Combination; Female; Imidazoles; Insecticides; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Tick Control; Tick Infestations; Time Factors; Treatment Outcome

Topics: Animals; Dog Diseases; Dogs; Drug Therapy, Combination; Ehrlichiosis; Female; Imidazoles; Insecticides; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Tick Infestations; Ticks; Treatment Outcome

This work evaluated tick and flea burdens and the efficacy of a single topical application of 10% fipronil + 9% (S)-methoprene spot-on against experimental infestations of Rhipicephalus sanguineus sensu lato and Ctenocephalides felis felis on dogs that were submitted to regular baths for 56-days post-treatment. Four treatments (n = 24) were evaluated: no chemical treatment and no bathing (T01); no chemical treatment + bathing (T02); chemical treatment and no bathing (T03) and chemical treatment + bathing (T04). Dogs were infested with adult ticks and fleas seven days pre-treatment (-7). The ectoparasites were then counted and removed on day -5, followed by a new infestation on day -2 and treatment on day 0. Ticks and fleas were then counted without removal on day 1 and counted with removal on day 2. The dogs were then repeatedly infested with both ectoparasites on days 5, 12, 19, 26, 33, 40, 47 and 54 post-treatment. Baths and ectoparasite counts with removal were performed every 48 h before and after experimental infestation, respectively. Animals of T04 had lower (P ≤ 0.05) tick burden than animals from T01 and T02 from day 2 to day 28. For fleas, the counts varied among days of the study. Dogs from T03 presented lower (P ≤ 0.05) flea burden than dogs from T01 from day 1 until day 56. The same was true for T04 when compared to T01 from day 1 to day 42. Animals of T02 greater (P ≤ 0.05) flea burden than animals of T04 in all dates post treatment. In addition, dogs from T02 presented higher (P ≤ 0.05) flea burden than T01 from day 7 to day 28 and from day 49 to day 56. In sum, the efficacy of the spot-on formulation used declined over the time against both ectoparasites. The efficacy for ticks ranged from 0.0 to 96.5% and 0.0 to 98.52% for T03 and T04, respectively. While for fleas, the efficacy of the formulation ranged from 67.41 to 100% for T03 and 40.18 to 100% for T04. So, bathing dogs that were not treated increased C. f. felis burden but not R. sanguineus s. l. burden. The residual efficacy of the product had a shorter duration against these ectoparasites for dogs that received subsequent bathing.

Topics: Administration, Topical; Animals; Baths; Dog Diseases; Dogs; Female; Flea Infestations; Insecticides; Male; Methoprene; Pyrazoles; Tick Infestations

This study was designed to compare the therapeutic and residual efficacy for 1 month of three topical ectoparasiticides on mixed-bred dogs against the brown dog tick, Rhipicephalus sanguineus. Adult dogs (n = 32, 10.8-18.4 kg BW) were allocated to 4 groups (n = 8) and infested with 50 adult ticks on days -8, -2, 7, 14, 21, and 28. Within each group, dogs were treated topically on day 0 with a control solution (CS), Vectra 3D (DPP), Frontline Plus (FM), or K9 Advantix (IP). Ticks were enumerated on dogs 24 h after treatment and each subsequent tick infestation by in situ thumb count assessment without removal and at 48 h by combing and removal. Acaricidal efficacy was calculated using arithmetic means for all 24 and 48 h tick count assessments. From 42 to 56% of the total, infested ticks were found on dogs 48 h post-challenge in the CS group. Therapeutic efficacy for all treatments ranged from 45.5 to 64.6% after 48 h of infestation. Residual efficacy after FM treatment was consistently lower compared to DPP or IP treatments at the 24 h assessments on days 8, 22, 23, and 29. Residual efficacy measured at this last time point was 94.8% for DPP, 83.1% for IP, and 46.9% for FM. This study demonstrates that permethrin-based formulations (DPP and IP) provided a quicker onset of residual protection against brown dog ticks compared to FM. Although DPP and IP are both permethrin-based formulations, DPP exhibited consistently higher residual acaricidal efficacies and was the only treatment that provided >90% protection for 1 month at 24 h post challenge.

Topics: Acaricides; Animals; Dog Diseases; Dogs; Female; Hair; Male; Methoprene; Permethrin; Pyrazoles; Random Allocation; Rhipicephalus sanguineus; Tick Infestations

Efficacy of FRONTLINE TRITAK For Dogs (fipronil/(S)-methoprene/cyphenothrin, Merial, Inc., Duluth, GA) against Ixodes scapularis was evaluated in two separate, but concurrent laboratory studies.. One day after topical treatment with placebo or active, dogs (n = 24) were infested with 50 unfed adult Ixodes scapularis ticks, with repeat infestations on Days 7, 14, 21 and 28. The number of live ticks was counted at 6 hours post-infestation in the first study (n = 12) and at 24 hours post-infestation in the second study (n = 12).. Observed efficacies in study 1 were 93-99% at 6 hour assessments on Day 1 through Day 28 and in the second study, 98-100% at 24 hour assessments, occurring on Day 2 through Day 29.. A single dose of FRONTLINE TRITAK For Dogs (fipronil/(S)-methoprene/cyphenothrin) (0.67 ml or 1.34 ml) prevented the establishment of a new infestation following treatment, as well as the repeated weekly re-infestations with Ixodes scapularis ticks, for 4 weeks.

Topics: Administration, Topical; Animals; Dog Diseases; Dogs; Drug Compounding; Female; Insecticides; Ixodes; Male; Methoprene; Pyrazoles; Pyrethrins; Random Allocation; Tick Control; Tick Infestations

A 28-day study was conducted to assess the dynamic of blood feeding by Rhipicephalus sanguineus ticks on dogs treated or not with a novel topical combination of fipronil, amitraz and (S)-methoprene. Dogs were infested weekly through exposure to ticks in crates for 4h. Ticks were then counted in the crates at 2h and 4h post dog exposure. Ticks were also counted and removed from the dogs at 2h, 4h, 6h, 12h and 24h post tick exposure. The inhibition of blood feeding was assessed by both tick quantification and designing and performing a quantitative PCR (qPCR) to detect the canine hydroxymethylbilane synthase (HMBS) gene in ticks. The percentage of repellency sensu lato based on the ticks collected in crates at 2h varied from 4.7% at day 28 to 48.3% at day 7. The immediate mortality rate of the ticks expelled at 2h varied from 1.5% at day 21 to 31.7% at day 7. The efficacy calculation showed that the acaricidal combination started to kill ticks in as little as 2h. The average efficacy reached 90.0% at 12h post crate challenges and 100% at 24h post exposure in crates. The inclusion of an internal amplification control was used to ensure that no significant template-derived PCR inhibition (≤ 6.2%) affected the overall results. The reduction of blood feeding was significant at 4h (>80.0%) and >99.0% at 24h post tick exposure in the crate. The high repellency rate and the lethal efficacy of CERTIFECT(®) resulted in significantly fewer live attached ticks, consequently reducing blood intake and fluid exchanges.

Topics: Acaricides; Animals; Dog Diseases; Dogs; Drug Combinations; Feeding Behavior; Female; Hydroxymethylbilane Synthase; Male; Methoprene; Pyrazoles; Rhipicephalus sanguineus; Tick Infestations; Toluidines

Five controlled, blinded and randomized studies were conducted to examine the efficacy of a single topical application of a combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel (BROADLINE(®), Merial) against induced infestations with Ixodes ticks on cats. Three studies investigated the efficacy against Ixodes ricinus and two against Ixodes scapularis. In each study, purpose-bred cats were assigned at random to an untreated group or to a treated group. For the studies using I. ricinus, cats were infested with 50 female ticks and a similar number of males 2 days before treatment application, and weekly afterwards on between four and six occasions. For the studies using I. scapularis, cats were infested with a total of 50 ticks (approximately 25 females and 25 males) according to the same schedule as for I. ricinus. Tick counts for the evaluation of efficacy were performed 48 h after treatment and 48 h after the subsequent weekly infestations. Weekly attachment rates to untreated cats of at least 29% for I. ricinus and at least 30% for I. scapularis demonstrated consistently that the ticks were vigorous and that the attachment rates were adequate for efficacy evaluation. In the I. ricinus studies, an efficacy of at least 93% was demonstrated for up to 37 days after the treatment. In the I. scapularis studies, the efficacy level was at least 95% 30 days after the treatment. The product was well tolerated and caused no adverse reaction.

Topics: Animals; Antiparasitic Agents; Cat Diseases; Cats; Drug Combinations; Female; Ivermectin; Ixodes; Male; Methoprene; Praziquantel; Pyrazoles; Random Allocation; Tick Infestations; Treatment Outcome

Tick-borne infections resulting from regular tick infestation in dogs are a common veterinary health problem all over the world. The application of repellent and acaricidal agents to prevent transmission of pathogens is a major protection strategy and has been proven to be highly effective in several trials under laboratory and natural conditions in dogs. Despite such promising results, many dog owners still report tick infestation in their dogs although acaricidal agents are used. Information about the current infection status and changes of the infection status regarding tick-borne diseases (TBD) in dogs treated by the owner's controlled acaricide application is lacking.. In this study 30 dogs were each treated with permethrin, fipronil + S-methoprene, or served as untreated controls. Application of the acaricide was performed by the owner who decided when and how often to use the spot on preparation. Over a period of 11 months, dogs were clinically examined and sampled for antibody responses against Babesia canis, Anaplasma phagocytophilum, Borrelia burgdorferi s. l., and TBE virus before the study started, 6 months later and at the end of the investigation period.. The permethrin acaricide was applied on average 3.40 times within the examination period, whereas the fipronil + S-methoprene medication was applied 3.03 times. Approximately 2/3 of all dogs, independent of the group, had a positive immune response to one or more pathogens. Three dogs developed clinical symptoms of canine babesiosis, all other dogs remained healthy. Individual number of ticks per dog or number of infections per dog did not correlate with the application rate, and the number of ticks per dog did not influence the number of infections per dog. As owners did not apply the acaricides regularly no influence on the number of infections could be documented although the number of ticks was clearly reduced by the application of the spot-on drugs.. Clinical disease in dogs exposed to tick-borne pathogens is rare, although a humoral immune response reflecting infection is common. More educational training for dog owners is necessary to make the application of acaricides effective regarding the prevention of tick-borne diseases.

Topics: Acaricides; Animals; Austria; Dog Diseases; Dogs; Female; Humans; Male; Methoprene; Permethrin; Prevalence; Pyrazoles; Tick Infestations; Tick-Borne Diseases

The ability of CERTIFECT(®) (a combination of fipronil, amitraz and (S)-methoprene) to prevent transmission of Ehrlichia canis was studied in two groups of eight dogs. One group was treated with CERTIFECT while the other group remained untreated. All dogs were exposed to E. canis-infected Rhipicephalus sanguineus ticks on Days 7, 14, 21 and again on day 28 post-treatment by releasing ticks into the kennels of the dogs to simulate the natural way of infestation. Animals were examined in situ for ticks on Days 9, 16 and 23 and any ticks present were counted and removed on Day 30. The efficacy of CERTIFECT against R. sanguineus was 100%, since no ticks were found on the treated dogs at any time. Clinical examinations (including monitoring body temperature and blood collections for PCR analysis and serology) were performed at intervals throughout the study until Day 56. Five out of 8 untreated control dogs (62.5%) became infected with E. canis, as demonstrated by detection of specific E. canis antibodies and the presence of E. canis DNA in blood samples by PCR. These dogs displayed fever and thrombocytopenia and were rescue-treated with doxycline. None of the 8 dogs treated with CERTIFECT became infected with E. canis, in comparison to the 5/8 control dogs, as confirmed by the lack of specific antibodies and absence of any ehrlichial DNA in blood samples by PCR. CERTIFECT prevented transmission of E. canis and effectively provided protection against monocytic ehrlichiose for at least 4 weeks post treatment.

Topics: Administration, Topical; Animals; Dog Diseases; Dogs; Drug Combinations; Ehrlichia canis; Ehrlichiosis; Insecticides; Methoprene; Pyrazoles; Rhipicephalus sanguineus; Tick Infestations; Toluidines

Certain tick species including Ixodes holocyclus can inoculate neurotoxins that induce a rapid, ascending flaccid paralysis in animals. Rhipicephalus sanguineus, the most widespread tick of dogs, is recognized as a vector of several pathogens causing diseases in dogs and humans. A single report suggests its role as cause of paralysis in dogs. This study presents the clinical history of 14 young dogs heavily infested by R. sanguineus (intensity of infestation, 63-328) in an endemic area of southern Italy. During May to June of 2011, dogs were presented at the clinical examination with neurological signs of different degrees (e.g., hind limb ataxia, generalized lethargy, and difficulty in movements). All animals were treated with acaricides and by manual tick removal but ten of them died within a day, displaying neurological signs. The other 4 dogs recovered within 3 days with acaricidal and supportive treatment. Twelve dogs were positive by blood smear examination for Hepatozoon canis with a high parasitemia, two also for Babesia vogeli and two were negative for hemoparasites. Low-grade thrombocytopenia, hypoalbuminemia, and pancytopenia were the haematological alterations most frequently recorded. Other causes of neurological disease in dogs were excluded and the diagnosis of tick paralysis by R. sanguineus was confirmed (ex juvantibus) by early and complete recovery of 4 dogs following acaricidal treatment and tick removal.

Topics: Acaricides; Animals; Dog Diseases; Dogs; Female; Italy; Male; Methoprene; Parasitemia; Pyrazoles; Rhipicephalus sanguineus; Tick Infestations; Tick Paralysis

A novel combination of fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) was evaluated for the prevention of attachment of ticks and its ability to cause detachment of ticks. For the two prevention of attachment studies, 20 purpose-bred beagles were allocated each to two equal groups based on pretreatment tick counts (treated and untreated). Each dog was exposed to 50 adult Rhipicephalus sanguineus and Dermacentor variabilis weekly starting 24h after treatment. In study 1 infestations with R. sanguineus were discontinued after Day 7 but continued to Day 28 for D. variabilis in both studies. Counts of ticks by species were made 2, 4 and 24h after exposure to ticks. Ticks not attaching to dogs were evaluated for viability. For the evaluation of detachment study, 16 purpose-bred beagles were allocated each to two equal groups based on pretreatment tick counts (treated and untreated). Each dog was infested with 50 unfed R. sanguineus and D. variabilis adults on Day -2. Ticks were thumb counted without removal on all dogs on Day -1, and at 4, 12, and 24h after treatment. Ticks were counted and removed at 48 h after treatment. Dogs treated with the novel combination had significantly (p<0.05) lower total numbers of attached R. sanguineus and D. variabilis than untreated controls at 4h through Day 7. For R. sanguineus, percent reduction of attachment at 24h after infestation through Day 29 ranged from 94.5% to 100%. For D. variabilis, the percent reduction of attachment at 24h through Day 22 was above 98.0%. These studies demonstrate that novel combination can disrupt attachment of R. sanguineus and D. variabilis for up to 28 days following treatment. Of those ticks that are exposed to the treatment, even if they do not attach to the dog and remain in the environment, greater than 90% (p<0.05) die within 24h for 2-3 weeks following treatment. Also, for those dogs infested with ticks at the time of treatment, the novel combination causes significant detachment (p<.05) starting at 12h and reaching 98.9% by 48 h after treatment. This product provides an effective means for controlling ticks infesting dogs and limiting the spread of tick transmitted diseases. Additionally, the mortality of ticks exposed to CERTIFECT will reduce infestation of the dog's environment.

Topics: Administration, Topical; Animals; Dermacentor; Dog Diseases; Dogs; Drug Combinations; Female; Insecticides; Male; Methoprene; Pyrazoles; Random Allocation; Rhipicephalus sanguineus; Tick Infestations; Toluidines

Four laboratory studies were conducted to demonstrate that a single topical dose of a novel spot-on combination containing fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) is efficacious against the brown dog tick, Rhipicephalus sanguineus. In each study, 6-8 male and 6-8 female purpose-bred, laboratory mongrels, terrier cross or Beagles were randomly assigned to one of two study groups (treated and untreated), based on pre-treatment parasite counts. Starting on the day before treatment, each dog was infested weekly with 50 ticks. Ticks were thumb counted at various time points after treatment and weekly infestations starting as early as 6h and continued at 12, 18 and 24h depending on the study. Ticks were removed and counted at 48 h after treatment and weekly infestations. CERTIFECT provided rapid and excellent control of pre-existing and newly acquired infestations of R. sanguineus with efficacy as high as 93% within the first 12h after a single topical treatment. Excellent control (>96%) of R. sanguineus as early as 18 h, following post treatment infestations was maintained for at least 35 days.

Topics: Administration, Topical; Animals; Dog Diseases; Dogs; Drug Combinations; Female; Insecticides; Male; Methoprene; Pyrazoles; Random Allocation; Rhipicephalus sanguineus; South Africa; Tick Control; Tick Infestations; Toluidines; Treatment Outcome; United States

The acaricidal efficacy against Dermacentor reticulatus in dogs of the commercial topical combinations fipronil/(S)-methoprene (FRONTLINE Combo spot-on dog), imidacloprid/permethrin (Advantix) and metaflumizone/amitraz (ProMeris Duo) was evaluated and compared. Three treatment groups and one untreated control group of six adult Beagle dogs each were randomly formed. Each treatment was administered topically once on Day-0, according to the recommended label dose and instructions for use. All dogs were infested weekly with approximately 50 adult unfed D. reticulatus over a period of seven weeks. Ticks were removed and counted approximately 48 hours after each infestation. The percent reduction in numbers of ticks for fipronil/(S)-methoprene was > or = 97% compared to untreated controls for all seven weekly infestations. The percent reductions for imidacloprid/permethrin and metaflumizone/amitraz were satisfactory initially but fell and stayed below 90 % after three weeks. From the third week onwards, fipronil/(S)-methoprene treated dogs had significantly fewer ticks than imidacloprid/permethrin or metaflumizone/amitraz treated dogs (p < 0.05).

Topics: Animals; Dog Diseases; Dogs; Drug Therapy, Combination; Imidazoles; Insecticides; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Tick Infestations; Treatment Outcome

This study evaluated the effectiveness of two topical spot-on formulations -- imidacloprid(8.8% w/w)-permethrin (44.0% w/w) and fipronil (9.8% w/w)-(S)-methoprene (8.8% w/w)--to repel, prevent the attachment of, and kill adult Ixodes scapularis and Amblyomma americanum on dogs. Twelve purpose-bred beagles were distributed into three groups of four dogs each; one group served as untreated controls, and each of the other two groups received one of the test products. Dogs were exposed to 25 adult ticks of each species for 10 minutes on posttreatment days 3, 7, 14, 21, and 28. Unattached or repelled ticks were collected and evaluated for viability, and on-dog tick counts were conducted at 3, 24, and 48 hours after tick exposure. The imidacloprid-permethrin formulation provided significant repellency against I. scapularis for up to 3 weeks after treatment, and both formulations provided good overall control of I. scapularis and A. americanum during the study period.

Topics: Administration, Topical; Animals; Dog Diseases; Dogs; Female; Imidazoles; Insecticides; Ixodes; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Random Allocation; Tick Control; Tick Infestations; Ticks; Time Factors; Treatment Outcome

This study evaluated the effectiveness of two topical spot-on formulations, imidacloprid (8.8% w/w)--permethrin (44.0% w/w) and fipronil (9.8% w/w)--(S)-methoprene (8.8% w/w), to repel, prevent the attachment of, and kill adult Rhipicephalus sanguineus and Dermacentor variabilis on dogs. Twelve purpose-bred beagles were distributed into three groups of four dogs each; one group served as untreated controls and each of the other two groups received one of the test products. Dogs were exposed to 25 adult ticks of each species for 10 minutes on posttreatment days 3, 7, 14, 21, and 28. Nonattached or repelled ticks were collected and evaluated for viability, and on-dog tick counts were conducted at 3, 24, and 48 hours after tick exposure. The imidacloprid-permethrin formulation provided significant repellency of R. sanguineus and D. variabilis for up to 3 and 4 weeks after treatment, respectively; and provided good overall control for R. sanguineus and D. variabilis during the study period. The fipronil--(S)-methoprene formulation provided good overall tick control during the study period.

Topics: Administration, Topical; Animals; Dermacentor; Dog Diseases; Dogs; Female; Imidazoles; Insecticides; Male; Methoprene; Neonicotinoids; Nitro Compounds; Permethrin; Pyrazoles; Random Allocation; Rhipicephalus sanguineus; Tick Control; Tick Infestations; Time Factors; Treatment Outcome