Efficacy of two endectoparasiticide products combining fipronil and (S)-methoprene or esafoxolaner with eprinomectin and praziquantel against fleas and intestinal helminths in cats naturally infested in Brazil.

Eprinomectin and praziquantel, nematodicide and cestodicide compounds, are both combined with the insecticide and acaricide compounds fipronil and (S)-methoprene in Frontline® Protect/Broadline®, or esafoxolaner in NexGard® Combo. These topical feline endectoparasiticide products were tested for efficacy against fleas and intestinal helminths in a field trial in Brazil. Flea- and/or helminth-infested domestic cats were treated twice at a monthly interval following label instructions: 160 cats with Frontline® Protect/Broadline® and 165 cats with NexGard® Combo. The flea and intestinal helminth infestations were evaluated using comb counts and copromicroscopy, respectively before first treatment for baseline value, then 9 and 30 days after each treatment for fleas, and 9 days after each treatment for helminths. Multiparasitism was very frequent at baseline, as amongst the 325 included cats, 295, 280, 86 and 93 cats were at least infested with Ctenocephalides fleas, Ancylostoma, Toxocara and Dipylidium caninum, respectively. Efficacies were calculated by comparing the geometric means at baseline and at post-treatment timepoints for each parasite genus/species. Inclusive of both products and of all evaluation timepoints, the Ctenocephalides, Ancylostoma, Toxocara and D. caninum efficacies were at least 98.3%, 99.8%, 99.8% and 96.3%, respectively. No adverse reactions were observed, except for a few instances of mild, transient, and self-resolving hypersalivation occurring on the day of treatment in both groups. This field trial demonstrated high-level efficacy of Frontline® Protect/Broadline® and NexGard® Combo against major parasites of cats in Brazil.

TITLE: Efficacité de deux produits endectoparasiticides associant fipronil et (S)-méthoprène ou esafoxolaner à l'éprinomectine et au praziquantel contre les puces et les helminthes intestinaux chez les chats naturellement infestés au Brésil. ABSTRACT: L'éprinomectine et le praziquantel, composés nématodicides et cestodicides, sont tous les deux associés aux composés insecticides et acaricides fipronil et (S)-méthoprène dans Frontline® Protect/Broadline®, ou esafoxolaner dans NexGard® Combo. Ces produits endectoparasiticides félins topiques ont été testés pour leur efficacité contre les puces et les helminthes intestinaux lors d'un essai sur le terrain au Brésil. Des chats domestiques infestés de puces et/ou d'helminthes ont été traités deux fois à intervalle d'un mois en suivant les instructions d'utilisation, 160 chats avec Frontline® Protect/Broadline® et 165 chats avec NexGard® Combo. Les infestations par les puces et les helminthes intestinaux ont été évaluées en utilisant respectivement par comptage au peigne et par copromicroscopie, avant le premier traitement pour la valeur de base, puis 9 et 30 jours après chaque traitement pour les puces, et 9 jours après chaque traitement pour les helminthes. Le multiparasitisme était très fréquent à l'inclusion puisque parmi les 325 chats inclus, 295, 280, 86 et 93 chats étaient au moins infestés respectivement par les puces Ctenocephalides, ou Ancylostoma, Toxocara et Dipylidium caninum. Les efficacités ont été calculées en comparant les moyennes géométriques au départ et aux points d'évaluation post-traitement pour chaque genre/espèce de parasite. En incluant les deux produits et tous les points temporels d'évaluation, les efficacités contre Ctenocephalides, Ancylostoma, Toxocara et D. caninum étaient respectivement d'au moins 98,3 %, 99,8 %, 99,8 % et 96,3 %. Aucun effet indésirable n'a été observé à l'exception de quelques cas d'hypersalivation légère, transitoire et auto-résolvante survenant le jour d'un traitement dans les deux groupes. Cet essai sur le terrain a démontré une efficacité de haut niveau de Frontline® Protect / Broadline® et NexGard® Combo contre les principaux parasites des chats au Brésil.

Efficacy of fipronil/(S)-methoprene/eprinomectin/praziquantel (Broadline®) against Thelazia callipaeda in naturally infected cats.

BACKGROUND: The present clinical field trial was conducted to assess the efficacy of a broad-spectrum parasiticide spot-on formulation containing eprinomectin (Broadline®) against Thelazia callipaeda eyeworm in naturally infected cats. METHODS: Fifteen privately owned cats harboring at least one live adult T. callipaeda were included in the study. Cats were randomly allocated to an untreated control group of seven cats or to a Broadline®-treated group of eight cats. Cats were treated on Day 0; ocular examinations were performed at inclusion and on Days 7 and 14; eyeworms were recovered and counted on Day 14. The primary efficacy assessment was based on group comparison of number of T. callipaeda on Day 14. RESULTS: Seven days after treatment, six of eight treated cats were negative for eyeworm infection per visual examination, and on Day 14 no eyeworms were found in the treated cats while the seven untreated cats were still infected (geometric mean: 1.97). All cats had inflammatory ocular signs at inclusion; on Day 14, five of eight treated cats had recovered while all untreated control cats were still symptomatic. All collected parasites were confirmed to be T. callipaeda by morphology and molecular characterization. CONCLUSIONS: A single treatment with Broadline® provided 100% efficacy against feline thelaziosis and improved related ocular inflammation signs.

Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against Notoedres cati mange in cats.

The therapeutic efficacy against notoedric mange of a topical combination of esafoxolaner, eprinomectin and praziquantel (Nexgard® Combo, Boehringer Ingelheim) was evaluated in a masked, controlled clinical study including 14 cats with natural or induced Notoedres cati infestation. Cats were allocated randomly to two groups of seven cats each, to be administered either mineral oil (placebo control) or NexGard® Combo. Each treatment was administered once as spot-on at 0.12 mL per kg body weight (representing the minimum label dosage of NexGard® Combo, i.e. 1.44 mg esafoxolaner, 0.48 mg eprinomectin, and 10.0 mg praziquantel per kg body weight). Live mites were counted in skin scrapings collected within seven days prior to and 14, 27/28, 42 and 56 days after treatment to calculate the percentage efficacy of NexGard® Combo based on the comparison of mean live mite counts of the two groups. Concurrently, mange lesions and clinical signs were scored to establish a clinical success valuation. No live mites were recovered from any NexGard® Combo-treated cats post-treatment, indicating 100% therapeutic efficacy following a single spot-on administration of the novel antiparasitic combination. The clinical success valuations in the NexGard® Combo-treated cats were 14.3%, 42.8%, 100% and 100% at 14, 27/28, 42 and 56 days after treatment, respectively. No health problems were observed throughout the study.

TITLE: Efficacité d'une nouvelle association topique d'esafoxolaner, d'éprinomectine et de praziquantel contre la gale à Notoedres cati chez le chat. ABSTRACT: L'efficacité thérapeutique contre la gale notoédrique d'une association topique d'esafoxolaner, d'éprinomectine et de praziquantel (Nexgard® Combo, Boehringer Ingelheim) a été évaluée dans une étude clinique contrôlée et masquée portant sur 14 chats atteints d'une infestation naturelle ou induite par Notoedres cati. Les chats ont été répartis au hasard en deux groupes de sept chats chacun, traités soit avec de l'huile minérale (contrôle placebo), soit avec NexGard® Combo. Chaque traitement a été administré en une seule fois à raison de 0,12 mL par kg de poids corporel (représentant la posologie minimale indiquée sur l'étiquette de NexGard® Combo, c'est-à-dire 1,44 mg d'esafoxolaner plus 0,48 mg d'éprinomectine plus 10,0 mg de praziquantel par kg de poids corporel). Les acariens vivants ont été comptés par grattage de peau et recueillis dans les sept jours précédant le traitement et 14, 27/28, 42 et 56 jours après le traitement pour calculer le pourcentage d'efficacité de NexGard® Combo basé sur la comparaison du nombre moyen d'acariens vivants des deux groupes. Parallèlement, les lésions de la gale et les signes cliniques ont été mesurés pour établir une évaluation du succès clinique. Aucun acarien vivant n'a été retrouvé chez les chats traités par NexGard® Combo après le traitement, ce qui indique une efficacité thérapeutique de 100% après une administration ponctuelle unique de la nouvelle association antiparasitaire. L'évaluation du succès clinique chez les chats traités par NexGard® Combo était de 14,3 %, 42,8 %, 100 % et 100 %, respectivement 14, 27/28, 42 et 56 jours après le traitement. Aucun problème de santé n'a été observé tout au long de l'étude.

Does bathing affect tick and flea burdens and ectoparasiticide effectiveness of a spot-on formulation (fipronil + (S)-methoprene) for dogs?

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.

Evaluation of an 11.2% spinetoram topical spot-on solution for the control of experimental and natural flea (Ctenocephalides felis) infestations on cats in Europe.

Spinetoram is the newest member the spinosyn-class of natural products to be commercialized for flea control on cats in the United States under the tradename Cheristin® for cats. This report describes results from two laboratory studies and a multi-center clinical field trial designed to confirm the efficacy of a topical spot-on solution containing spinetoram (11.2% w/w, 130 mg/mL) against European strains of the cat flea, Ctenocephalides felis. In the laboratory studies, cats were allocated to one of two treatment groups of eight animals each: negative control (mineral oil) or spinetoram, both applied as a topical spot-on at the base of the skull on Day 0. Cats were infested with ∼100 newly emerged, unfed adult fleas on Days -2 or -1, 7, 14, 21, 28 and 35. To calculate efficacy, fleas were counted and removed 48 h after treatment, and 48 h after each subsequent infestation through week 5. Spinetoram treatments provided 100% efficacy through at least day 16 and ≥ 97% efficacy (arithmetic mean) for one month. For the field trial, 23 clinics from Northern and Southern Europe participated in the study that compared the effectiveness and safety of spinetoram and fipronil/(S)-methoprene treatments over a period of two months. There were 258 and 248 evaluable efficacy cases for month 1 and month 2, respectively, with 300 total evaluable cases for safety. Treatments were administered on Day 0 and again on Day 30 (±3 days). The effectiveness of treatments was calculated based on reduction in live flea counts on Days 14, 30, 44 and 60 (±3 days) relative to flea counts obtained on Day 0. Efficacy (geometric mean percent flea reduction) on Days 14, 30, 44 and 60 was 97.0%, 95.0%, 99.3% and 99.1% for spinetoram, respectively, and 86.1%, 80.9%, 92.4% and 92.3% for fipronil/(S)-methoprene, respectively. Spinetoram was deemed non-inferior at all intervals and superior to fipronil/(S)-methoprene at Days 30 and 60. Clinical signs of flea allergy dermatitis (FAD) were markedly improved following spinetoram treatment, as demonstrated through statistically significant reductions in severity of FAD scores for most of the clinical signs when compared to fipronil/(S)-methoprene treatment. There was a lower overall adverse event incidence rate for spinetoram (5.1%) versus fipronil/(S)-methoprene treatment (11.5%).

A randomized, controlled field study to assess the efficacy and safety of lotilaner (Credelio™) in controlling fleas in client-owned cats in Europe.

BACKGROUND: Lotilaner is a new isoxazoline developed as an oral ectoparasiticide for cats and dogs. Its safety, rapid killing onset of action and sustained speed of fleas and ticks kill for a minimum of one month after administration, were demonstrated in a number of laboratory studies in cats. This study was performed to demonstrate the efficacy and safety of lotilaner flavored chewable tablets for cats (Credelio™, Elanco) in controlling fleas under field conditions in European countries. METHODS: Seventeen veterinary practices in France and Spain, located in high flea prevalence regions, participated in the study. Households with a maximum of three cats and two dogs were randomized 2:1 to a lotilaner (minimum dose rate 6 mg/kg) or a topical fipronil/(S)-methoprene combination (Frontline Combo® Spot-on Cats, Merial) group (administered according to label). In each household, efficacy against fleas and flea allergy dermatitis (FAD) signs were assessed in one primary cat (bearing a minimum of five fleas on Day 0) while safety was evaluated in all cats. There were 121 households included in the lotilaner and 61 in the fipronil/(S)-methoprene groups, respectively. Treatments were administered by the cats' owners on Day 0. Flea counts and FAD assessments were made on Days 0, 14, and 28. Efficacy calculations were based on geometric mean percent reductions of live flea counts versus baseline pre-treatment counts. RESULTS: Lotilaner efficacy was 97.2 and 98.1% on Days 14 and 28, respectively. Corresponding efficacy for fipronil/(S)-methoprene was 48.3 and 46.4%. Lotilaner was superior to fipronil/(S)-methoprene at all post-Day 0 assessments and over the whole study period (P < 0.0001). At every post-administration evaluation, at least 81% of lotilaner-treated cats were flea-free as opposed to 25% in the fipronil/(S)-methoprene group. Lotilaner improved or eliminated clinical signs of FAD, including pruritus. Both products were well tolerated. CONCLUSIONS: Under field conditions in Europe, lotilaner flavored chewable tablets for cats displayed an efficacy against fleas higher than 97%; clinical signs of FAD were improved or eliminated. Lotilaner tablets were safe and provided superior flea control to fipronil/(S)-methoprene.

Fipronil/(S)-methoprene spot-on to control fleas on cats in a field trial in Spain

The study was conducted in order to evaluate the effect of a fipronil/(S)-methoprene formulation against fleas on naturally infested cats. The study involved a population of 89 cats distributed among 24 veterinary practices in 9 regions of Spain. The product was applied according to label instructions on days 0, 30 and 60. Animals underwent parasitological and clinical assessments on day 0 and thereafter in monthly intervals (every 30 days) until day 90. Ctenocephalides felis was the most abundant species (98.9% of all fleas collected), and flea abundance on Day 0 was associated with the hair type, the location of the household, and the time elapsed from the last anti-flea treatment. Fipronil/(S)-methoprene demonstrated high efficacy and induced the reduction of clinical signs related to the presence of fleas. Clinical signs and flea abundance decreased significantly throughout time (P=0.001) with an efficacy rate of 72.6% at Day 30, 88.4% at Day 60 and 93.9% at Day 90. A high level of flea control and a remission of the clinical signs related to presence of fleas were observed on cats following 3 monthly applications a fipronil/(S)-methoprene formulation.(AU)

Efficacy of a topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel (Broadline(®)) against naturally acquired infections with cestodes of the genus Joyeuxiella in cats.

Cats are host to dipylidiid cestodes of the genera Diplopylidium, Dipylidium and Joyeuxiella. Broadline(®), a topical broad-spectrum combination parasiticide containing fipronil (8.3 % w/v), (S)-methoprene (10 % w/v), eprinomectin (0.4 % w/v) and the cestocide praziquantel (8.3 % w/v), has previously been shown to be efficacious against Dipylidium caninum and Diplopylidium spp. in cats. To evaluate its efficacy against Joyeuxiella species, a blinded clinical efficacy study was conducted according to GCP. All cats had evidence for naturally acquired dipylidiid cestode infection as confirmed by pre-treatment examination. Cats were allocated randomly to two groups of 13 cats each based on bodyweight: Control (untreated) and Broadline(®) at 0.12 mL/kg bodyweight administered once topically. Based on the comparison of helminth counts in the treated and untreated cats seven days post treatment, Broadline(®) demonstrated >99 % efficacy (p < 0.01) against mature J. fuhrmanni and J. pasqualei, with 11 and 13 of the untreated cats harbouring 1 to 102 or 2 to 95 cestodes, respectively. In addition, parasite counts indicated 95.9 % efficacy (p = 0.006) against the rictularoid nematode Pterygodermatites cahirensis.

Comparative Speed of Kill, Repellent (anti-feeding) and Acaricidal Efficacy of an Imidacloprid/Flumethrin Collar (Seresto®) and a Fipronil/(S)-Methoprene/Eprinomectin/Praziquantel Spot-on (Broadline®) against Ixodes ricinus (Linné, 1758) on Cats.

Speed of kill, repellent (anti-feeding) and acaricidal efficacy of an imidacloprid 10 % (w/w) /flumethrin 4.5 % (w/w) collar (Seresto(®), Bayer) and a spot-on formulation of fipronil 8.3 % (w/v) /(S)-methoprene 10 % (w/v) /eprinomectin 0.4 % (w/v) /praziquantel 8.3 % (w/v) (Broadline(®), Merial) against artificiallyinduced infestations with Ixodes ricinus on cats, were assessed in a parallel group design, randomised, controlled study. Twenty-four cats were included and randomly allocated to treatment groups or a non-treated control group. Starting on Day (D) 7 after treatment until D28, cats were each infested with 50 I. ricinus at weekly intervals. Ticks were counted in situ on the cats at 6, 12 and 24 h and upon removal 48 h after each infestation. Based on arithmetic means, Seresto(®) proved to be 100 % effective against adult I. ricinus at all assessment times (6, 12, 24 and 48 h after infestation) throughout the month-long study. Broadline(®) was 0 % to 16.7 % effective at 6 h, 26.8 % to 50.0 % effective at 12 h, while at 24 h after infestation efficacy peaked at 81.5 % on D15 declining to 31.5 % on D29. Based on the 48 h tick counts, the efficacy of Broadline(®) peaked at 100 % on D16 after treatment and decreased to 83.2 % by D30. The Seresto(®) collar provided significantly faster speed of kill and better persistent acaricidal effectiveness against Ixodes ricinus on cats compared to Broadline(®) spot-on. The additional repellent (anti-feeding) effect of Seresto(®) prevents parasites from taking a blood meal and thereby reduces the risk of vector-borne disease pathogen transmission.

Efficacy of Broadline® spot-on against Aelurostrongylus abstrusus and Troglostrongylus brevior lungworms in naturally infected cats from Italy.

The increasing reports of Aelurostrongylus abstrusus infection and the new information on Troglostrongylus brevior have spurred the interest of the scientific community towards the research of pharmaceutical compounds effective against both pathogens. A novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel (Broadline®, Merial) has been released for the treatment of a variety of feline parasitic infections. The present study reports the efficacy of this spot-on in treating cats naturally infected by feline lungworms. Client owned cats (n=191) were enrolled from three geographical areas of Italy and faecal samples were examined by floatation and Baermann techniques. Twenty-three individuals were positive for L1 of A. abstrusus (n=18) or T. brevior (n=3) or for both species (n=2) and they were topically treated with Broadline®. Seventeen of them were also concomitantly infected by other parasites. Four weeks after treatment, faecal samples were collected and examined to assess the efficacy of a single administration of the product. Based on lungworm larvae counts, the efficacy of the treatment was 90.5% or 100% for A. abstrusus or T. brevior, respectively. Cats released significantly lower amounts of lungworm larvae after treatment compared to pre-treatment (p<0.0001). All but three cats were negative for other nematodes after treatment and all cats recovered from respiratory signs. Results of this study indicate that a single administration of the topical combination fipronil, (S)-methoprene, eprinomectin and praziquantel is effective and safe for the treatment of A. abstrusus and/or T. brevior infections in cats living under field conditions.

Therapeutic efficacy of Broadline against notoedric mange in cats.

The efficacy of a novel topical combination of fipronil 8.3% w/v, (S)-methoprene 10 % w/v, eprinomectin 0.4% w/v, and praziquantel 8.3% w/v (Broadline, Merial) was evaluated in 18 cats naturally infested by Notoedres cati in a controlled, blinded clinical efficacy study. Cats were blocked on pretreatment bodyweight and randomly allocated to two groups of nine cats each. One group served as control (untreated) and one group was treated once topically with Broadline according to the label instructions. Skin scrapings (three scrapings per animal per occasion) were collected prior to treatment and every other week for 8 weeks thereafter and examined for live N. cati mites. In addition, lesions were evaluated at each sampling to monitor the clinical recovery. Based on live mite counts, efficacy against N. cati of a single topical administration with Broadline was >99%, and all treated cats recovered from clinical signs of notoedric mange. No treatment-related adverse events were observed.

Preventive efficacy of a topical combination of fipronil--(S)-methoprene--eprinomectin--praziquantel against ear mite (Otodectes cynotis) infestation of cats through a natural infestation model.

A study based on naturally infested cats was designed to evaluate the effectiveness of a single treatment with a topical formulation containing fipronil, (S)-methoprene, eprinomectin and praziquantel, for the prevention of Otodectes cynotis infestation in cats. Six treated cats and six untreated cats were housed with three chronically Otodectes cynotis-infested cats, respectively. The cats of each group were kept together in a 20-m(2) room for 1 month. Both clinical examination and ear mite counts were conducted on Day 28. All donor cats were confirmed to be chronically infested with Otodectes cynotis on Day -1 and Day 28. From untreated control cats, 129 live mites were recovered on Day 28 and all cats were found to be infested. In the treated group, three cats were found to be infested, with a total of five live mites recovered, the difference between the two groups being significant (p = 0.003). One treatment corresponded to 96% preventive efficacy at Day 28 based on ear mite counts. With regard to cerumen, the clinical score increased significantly for untreated cats between Day -1 and Day 28 (p = 0.00026) and not for treated cats (p = 0.30). The difference in cerumen abundance was significant between untreated and treated cats on Day 28 (p = 0.0035). Concerning the pruritic reflex in at least one ear, all cats were negative at inclusion. All six untreated cats became positive and showed a reflex on Day 28, whereas no treated cat showed ear pruritus (p = 0.00026).

Fipronil-amitraz-S-methoprene-triggered pemphigus foliaceus in 21 dogs: clinical, histological and immunological characteristics.

BACKGROUND: A recently launched topical ectoparasiticide containing fipronil, amitraz and S-methoprene has been associated with the development of an acantholytic pustular dermatitis similar to that of Promeris-triggered pemphigus foliaceus (PF). HYPOTHESIS/OBJECTIVES: Our objectives were to describe the clinical, histological and immunological features of this PF-like cutaneous adverse drug reaction. ANIMALS: Twenty-one dogs with a probable or definitive diagnosis of PF-like cutaneous adverse drug reaction were identified between May 2012 and February 2013. MATERIAL AND METHODS: Histology, direct and indirect immunofluorescence were employed to address the study objectives. RESULTS: Most dogs were middle-aged or older (median, 9 years) and of large size (median, 23 kg). In six dogs (29%), the PF-like lesions remained confined to the site of application, while 15 dogs (71%) exhibited lesions at distant sites. One or two applications of the ectoparasiticide were sufficient to trigger PF-like lesions in seven (33%) and six (29%) dogs, respectively. Systemic signs were reported in nine dogs (43%), all with lesions extending to sites distant from application areas. Tissue-bound antikeratinocyte IgG was detected in the lesional epidermis of eight of 19 (42%) cases by direct immunofluorescence, while serum antikeratinocyte IgG was detected in 10 of 14 (71%) cases by indirect immunofluorescence. Autoantibodies were found to target canine desmocollin-1 in 11 of 14 dogs (79%), but not canine desmoglein-1, by indirect immunofluorescence on transfected cells. These immunological findings were similar in cases with localized and distant disease. CONCLUSIONS AND CLINICAL IMPORTANCE: This new topical ectoparasiticide containing fipronil, amitraz and S-methoprene is capable of triggering the development of an acantholytic pustular dermatosis that is a clinical, histological and immunological close match for Promeris-triggered PF and naturally occurring autoimmune PF in dogs.

Evaluation of indoxacarb and fipronil (s)-methoprene topical spot-on formulations to control flea populations in naturally infested dogs and cats in private residences in Tampa FL. USA.

BACKGROUND: A study was conducted to evaluate and compare the effectiveness of two different spot-on topical flea products to control flea infestations on naturally infested dogs and cats in Tampa, FL USA. METHODS: Thirty-two dogs and 3 cats with natural flea infestations living in 18 homes were treated topically with a 19.53% w/w spot-on formulation of indoxacarb. Another thirty dogs and 2 cats living in 19 different homes were treated topically with either fipronil (9.8% w/w)/(s)-methoprene (8.89% w/w) or fipronil (9.8% w/w)/(s)-methoprene (11.8% w/w), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28-30, 40-45, and 54-60. RESULTS: A single application of the indoxacarb or fipronil (s)-methoprene formulations reduced flea populations on pets by 97.8% and 85.5%, respectively within 7 days. One month (28-30 days) after treatment the indoxacarb and fipronil (s)-methoprene formulations reduced on-animal flea burdens by 95.0% and 49.5%, respectively. Following two monthly applications of either the indoxacarb or fipronil (s)-methoprene formulations, pet flea burdens were reduced by 99.1% and 54.8%, respectively, by days 54-60. At the end of the two month study, 77.1% and 15.6% of the dogs and cats in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively were flea free. Flea numbers in the indoor-premises were markedly reduced in both treatment groups by days 54-60, with 97.7% and 84.6% reductions in intermittent-light flea trap counts in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively. CONCLUSIONS: This in-home investigation conducted during the summer of 2013 in subtropical Tampa, FL, is the first published U.S field investigation of the indoxacarb topical formulation. The indoxacarb formulation was able to effectively control flea populations in heavily flea infested pets and homes. The efficacy achieved by the fipronil (s)-methoprene formulation against flea infestations on these pets was lower than in previous investigations using the same study design.

Comparative efficacy on dogs of a single topical treatment with fipronil/(S)-methoprene or weekly physiological hygiene shampoos against Ctenocephalides felis in a simulated flea-infested environment.

Flea infestations of pets continue to persist due to the lack of knowledge of flea biology and ecology. It is not unusual that pet owners believe regular hygiene, such as shampooing their dogs can replace regular insecticidal treatment. The objective of this study was to compare in a flea simulated environment, modelling exposure similar to that found in a home, that the use of regular physiological shampoo does not control fleas adequately when compared to a long acting topical formulation. Three groups of six dogs were formed: one untreated control group, one group treated monthly with the topical formulation of fipronil/(S)-methoprene, and a third group treated weekly with a hygiene shampoo. All dogs were infested with adult unfed Ctenocephalides felis fleas (200±5) on Days -28 and -21. Each animal's sleeping box was fitted with a plastic cup mounted to the inside roof of the box. The sleeping bench of each animal was covered with a carpet to accommodate flea development. The dogs were maintained in their kennels throughout the study. In order to maintain the environmental flea challenge, C. felis pupae (100±5) were placed in the plastic cup in each animal's sleeping box on Days -14, -7, 0, 7, 14, 21, 28, 35 and 42. The dogs were combed and fleas counted weekly on Days -1, 3, 10, 17, 24, 31, 38, 45, and 51. The fleas were placed immediately back on the dogs. On Day 60, fleas were counted and removed. Flea infestations in the untreated control group at each count averaged between 46.2 and 74.2 fleas throughout the study. The average number of fleas infesting dogs was significantly different (p<0.05) between the untreated and the two treatment groups and between the two treatment groups at all counts throughout the two months study (Days 3, 10, 17, 24, 31, 38, 45, 51 and 60). The efficacy was never below 99.1% in the fipronil/(S)-methoprene group, and efficacy in the shampoo group was never above 79.2%. Weekly shampooing in treatment group 3 was intentionally delayed after Day 42, to evaluate wether missing a weekly bath would affect the flea population. The Day 48 data indicate that forgetting or delaying a single weekly shampooing resulted in a clear increase in flea numbers and a significant decrease in efficacy from 68.2% to 34.8%. The fipronil(S)/methoprene treatment allowed a continuous control as demonstrated by the high efficacy against fleas, and also the number of flea-free dogs on seven of the nine weekly assessments, in spite of what was essentially a continuous flea challenge model.

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations of brown dog ticks (Rhipicephalus sanguineus) on dogs.

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.

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations with four North American tick species (Dermacentor variabilis, Ixodes scapularis, Amblyomma americanum and Amblyomma maculatum) on dogs.

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.

Efficacy of a novel combination of fipronil, amitraz and (S)-methoprene for treatment and control of tick species infesting dogs in Europe.

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.

The ability of a topical novel combination of fipronil, amitraz and (S)-methoprene to protect dogs from Borrelia burgdorferi and Anaplasma phagocytophilum infections transmitted by Ixodes scapularis.

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.