Essential oil pharmaceuticals for killing ectoparasites on dogs.

BACKGROUND: External parasites, particularly ticks and fleas, are among the most common problems affecting dogs. Chemical medicines are commonly used to prevent and eliminate such external parasites, but their improper use can cause adverse reactions, and the toxins they contain may remain in the environment. OBJECTIVES: The objective of this study was to investigate the in vitro efficacy of Zanthoxylum limonella, citronella, clove, peppermint, and ginger essential oils against dog ticks and fleas and to test the sensitivity of dogs' skin to these essential oils. METHODS: The five essential oils were tested for in vitro efficacy against ticks and fleas, and the two most effective essential oils were then tested on the dogs' skin. RESULTS: The results revealed that these five essential oils at 16% concentrations effectively inhibited the spawning of female engorged ticks. In addition, all five essential oils had a strong ability to kill tick larvae at concentrations of 2% upward. Furthermore, 4% concentrations of the five essential oils quickly eliminated fleas, especially clove oil, which killed 100% of fleas within 1 h. A 50%, 90%, and 99% lethal concentration (LC50, LC90, and LC99) for the essential oils on tick larvae in 24 h were found to be low values. LC50, LC90, and LC99 for the essential oils on flea in 1 h was lowest values. Clove oil at 16% concentration was the most satisfactory essential oil for application on dogs' skin, with a low percentage of adverse effects. CONCLUSIONS: This study confirmed the effectiveness of essential oils for practical use as tick and flea repellents and eliminators. Essential-oil-based pharmaceutical can replace chemical pesticides and provide benefits for both consumers and the environment.

Year-round efficacy of a single treatment of fluralaner injectable suspension (Bravecto Quantum™) against repeated infestations with Rhipicephalus sanguineus (sensu lato) and Ctenocephalides felis in dogs.

BACKGROUND: Poor owner compliance with monthly control measures means that dogs in Australia can remain susceptible to infestations with fleas, present throughout the whole year, and brown dog ticks, which thrive in tropical and subtropical areas. A 150 mg/ml injectable fluralaner suspension (Bravecto Quantum™) was developed to help ensure year-round protection against these parasites. A study investigated the persistent efficacy of this formulation against repeated challenges with Rhipicephalus sanguineus (sensu lato) and Ctenocephalides felis throughout 12 months following a single subcutaneous treatment. METHODS: Twenty dogs were blocked by pre-treatment R. sanguineus s.l. counts and randomized to an untreated control group or to a group treated once, on day 0, with the fluralaner injection (15 mg/kg). Infestations of 50 mixed-sex, unfed adult R. sanguineus s.l. and up to 100 C. felis were done on days 7, 14, 35, 63, 91, 126, 154, 182, 210, 245, 273, 301, 336 and 365. Live flea and tick counts were completed 48 h post-infestation. Flea infestations were also done on day -1, with counts on day 2. Infestations were considered adequate if at each evaluation, at least six dogs in the control group retained at least 20% of tick challenges and 25% of flea challenges. RESULTS: The fluralaner injectable suspension was well tolerated. Efficacy against existing flea infestations was > 99% (arithmetic and geometric means) at 48 h post-treatment. At all subsequent assessments throughout the year following treatment, efficacy against fleas remained at 100%. Arithmetic mean tick count reductions relative to the control group ranged from 97.6% to 100% from day 7 through 11 months and was 92.6% at 12 months (geometric means 95.2% to 100% through 12 months). CONCLUSION: The injectable fluralaner suspension was effective against fleas and brown dog ticks for 12 months following a single treatment. Compared with more frequently administered products where compliance may be suboptimal, the year-round efficacy of this veterinarian-administered fluralaner formulation has the potential to improve owner compliance for control of fleas and ticks. In turn, by reducing the detrimental effects of flea and tick infestations and risk of transmission of flea- and tick-borne pathogens, canine health can be enhanced.

EVALUATING BAITS WITH LUFENURON AND NITENPYRAM FOR FLEA CONTROL ON PRAIRIE DOGS (CYNOMYS SPP.) TO MITIGATE PLAGUE.

Plague, caused by Yersinia pestis, is a widespread threat to endangered black-footed ferrets (Mustela nigripes) and their primary prey, prairie dogs (Cynomys spp.). Wildlife biologists most commonly manage plague using insecticides to control fleas, the primary vectors of Y. pestis. We tested edible baits containing the insecticides lufenuron and/or nitenpyram in prairie dogs. During a laboratory study, we treated 26 white-tailed prairie dogs (Cynomys leucurus) with lufenuron at 300 mg/kg body mass. All animals remained clinically healthy over the 9 wk monitoring period. Although serum lufenuron concentrations were >130 ppb in two treatment groups at week 1, concentrations declined to ≤60 ppb after 3 wk in non-torpid prairie dogs and after 7 wk in torpid prairie dogs. In a field experiment, we tested baits containing a combination of 75 mg lufenuron and 6 mg nitenpyram, respectively, in black-tailed prairie dogs (Cynomys ludovicianus). We uniformly distributed baits at 125 baits/ha on two plots (treated once) and 250 baits/ha on two plots (each treated twice 4.4 wk apart). Following treatments, flea abundance increased on prairie dogs and remained stable in burrows. Our findings indicate that baits containing lufenuron and nitenpyram, at the reported treatment rates, are ineffective tools for flea control on prairie dogs. Future experiments might evaluate efficacy of higher doses of lufenuron and nitenpyram, and repetitive treatments at differing intervals over time to evaluate potentially therapeutic treatments.

Effects of blood meal source on blood consumption and reproductive success of cat fleas, Ctenocephalides felis.

Cat fleas, small blood-feeding ectoparasites that feed on humans and animals, cause discomfort through their bites, and can transmit numerous diseases to animals and humans. Traditionally, fleas have been reared for research on live animals, but this process requires animal handling permits, inflicts discomfort on animals, and requires money and time to maintain the host animals. Although artificial membrane-based feeding systems have been implemented, these methods are not sustainable in the long term because they result in lower blood consumption and egg production than those with rearing on live hosts. To maximize these parameters, we tested blood from four hosts to determine the most suitable blood, on the basis of blood consumption and egg production. We also tested the effects of adding the phagostimulant adenosine-5´-triphosphate to the blood to maximize blood consumption. In 48 hours, fleas fed dog blood consumed the most blood, averaging 9.5 µL per flea, whereas fleas fed on cow, cat, or human blood consumed 8.3 µL, 5.7 µL, or 5.2 µL, respectively. Addition of 0.01 M and 0.1 M adenosine-5´-triphosphate to dog and cow blood did not enhance blood consumption. In a 1-week feeding period, the total egg production was also greatest in fleas fed dog blood, with females producing 129.5 eggs, whereas females on cat, human, and cow blood produced 97.2, 83.0, and 70.7 eggs, respectively. The observed results in dog blood indicate an improvement over previously reported results in cat fleas fed with an artificial feeding system. Improving the sustainability of rearing cat flea colonies without feeding on live animals will enable more humane and convenient production of this pest for scientific research.

Synergistic effects of EP-1 and ivermectin mixture (iEP-1) to control rodents and their ectoparasites.

BACKGROUND: Ectoparasites of rodents play significant roles in disease transmission to humans. Conventional poisoning potentially reduces the population densities of rodents, however, they may increase the ectoparasite loads on the surviving hosts. EP-1 has been shown to have anti-fertility effects on many rodent species, while ivermectin is effective in controlling ectoparasites. In this study, we examined the combined effects of EP-1 and ivermectin mixture (iEP-1) baits on rodents and their corresponding flea/tick loads. RESULTS: In males, the weight of testis, epididymis, and seminiferous vesicle were reduced to less than 33%, 25%, and 17%, respectively, compared to the control group following administration of iEP-1 for 7 days. The weight of the uterus increased by approximately 75%. After 5 days of iEP-1 intake, all ticks were killed, whereas 94% of fleas on mice died after 3 days of bait intake. In the field test near Beijing, the flea index was reduced by more than 90% after 7 days of iEP-1 bait delivery. In a field test in Inner Mongolia, the weights of testis, epididymis, and seminiferous vesicle were significantly reduced by 27%, 32%, and 57%, respectively, 2 weeks after iEP-1 bait delivery. Approximately 36% rodents exhibited obvious uterine oedema accompanied by a weight increase of about 150%. The flea index was reduced by over 90%. CONCLUSION: Our results indicated that iEP-1 is a promising treatment for reducing the abundance of both small rodents and their ectoparasites; this will be effective for managing rodent damage and transmission of rodent-borne diseases associated with fleas and ticks. © 2022 Society of Chemical Industry.

Assembling a safe and effective toolbox for integrated flea control and plague mitigation: Fipronil experiments with prairie dogs.

BACKGROUND: Plague, a widely distributed zoonotic disease of mammalian hosts and flea vectors, poses a significant risk to ecosystems throughout much of Earth. Conservation biologists use insecticides for flea control and plague mitigation. Here, we evaluate the use of an insecticide grain bait, laced with 0.005% fipronil (FIP) by weight, with black-tailed prairie dogs (BTPDs, Cynomys ludovicianus). We consider safety measures, flea control, BTPD body condition, BTPD survival, efficacy of plague mitigation, and the speed of FIP grain application vs. infusing BTPD burrows with insecticide dusts. We also explore conservation implications for endangered black-footed ferrets (Mustela nigripes), which are specialized predators of Cynomys. PRINCIPAL FINDINGS: During 5- and 10-day laboratory trials in Colorado, USA, 2016-2017, FIP grain had no detectable acute toxic effect on 20 BTPDs that readily consumed the grain. During field experiments in South Dakota, USA, 2016-2020, FIP grain suppressed fleas on BTPDs for at least 12 months and up to 24 months in many cases; short-term flea control on a few sites was poor for unknown reasons. In an area of South Dakota where plague circulation appeared low or absent, FIP grain had no detectable effect, positive or negative, on BTPD survival. Experimental results suggest FIP grain may have improved BTPD body condition (mass:foot) and reproduction (juveniles:adults). During a 2019 plague epizootic in Colorado, BTPDs on 238 ha habitat were protected by FIP grain, whereas BTPDs were nearly eliminated on non-treated habitat. Applications of FIP grain were 2-4 times faster than dusting BTPD burrows. SIGNIFICANCE: Deltamethrin dust is the most commonly used insecticide for plague mitigation on Cynomys colonies. Fleas on BTPD colonies exhibit the ability to evolve resistance to deltamethrin after repeated annual treatments. Thus, more tools are needed. Accumulating data show orally-delivered FIP is safe and usually effective for flea control with BTPDs, though potential acute toxic effects cannot be ruled out. With continued study and refinement, FIP might be used in rotation with, or even replace deltamethrin, and serve an important role in Cynomys and black-footed ferret conservation. More broadly, our stepwise approach to research on FIP may function as a template or guide for evaluations of insecticides in the context of wildlife conservation.

USING SURFACE WASHING TO REMOVE THE ENVIRONMENTAL COMPONENT FROM FLEA MICROBIOME ANALYSIS.

Microbial metabarcoding is a common method to study the biology of blood-feeding arthropods and identify patterns of potential pathogen transmission. Before DNA extraction, specimens are often surface washed to remove environmental contaminants. While surface washing is common, its effects on microbial diversity remain unclear. We characterized the microbiome of the flea species Ceratophyllus idius, an avian ectoparasite, and a potential vector of pathogens, using high-throughput 16S rRNA sequencing. Half of the nests from which fleas were collected were subjected to an environmental manipulation in which nesting materials were periodically replaced. In a crossed study design we surface washed half of the flea samples from each environmental condition to produce 4 experimental conditions. Environmental manipulations resulted in significant differences in the diversity and structure of the flea microbiome, but these differences were unapparent when specimens were surface washed. Furthermore, differential abundance testing of the experimental groups revealed that surface washing predominantly affected the abundance of bacterial groups that are characterized as environmental contaminants. These findings suggest that environmental changes primarily affect the surface microbiome of arthropods and that surface washing is a useful tool to reduce the footprint of the external microbiome on analysis.

Evaluating the potentials of randomised integrated control trial on tungiasis in a South-western Nigerian community.

Considering the fact that new, safe and incorporable treatment alternatives to therapeutic prophylaxis for tungiasis are lacking and sometimes proving difficult, this present study evaluated the potentials of integrating control approach involving focal premise treatment using 5% emulsifiable concentrate of cypermethrin, and topical application of Piper guineense oil with personal protection. Of the 90 houses selected, their floors were classified into paved rooms & unpaved verandas, paved verandas & unpaved rooms, paved rooms & verandas, and unpaved rooms & verandas, and tested for the presence of sand fleas using the sweeping and beating as well as soil collection and extraction by tullgren funnel method before fumigation. A total of 100 individuals partitioned into four groups of 25 individuals each were assigned 3%, 5%, 10% and 15% of P. guineense oil irrespective of stages of embedded fleas. The mean of sand fleas decreased from 1.14, 0.07, 0.21, and 1.66 to 0.37, 0.02, 0.09 and 1.08 after two weeks of single spray compared to the untreated location (p <  0.001). Furthermore, the mean lesions of stage I reduced to 0 after 2 to 6 days of 3%, 5%, 10% and 15% ointment application, and stage II and III after 10 to 12 days of 10% and 15% application respectively. The difference between tungiasis stages and exposure time for P. guineense ointment was highly significant p = 0.007 and p = 0.0002. Notable reduction in severity score of acute and chronic tungiasis was observed thus indicating effectiveness of the topical ointment. Hexanolic oil extracts of P. guineense in 10% and 15% concentration would kill embedded sand flea and ameliorate the sufferings in endemic settings.

Flea and tick treatment satisfaction, preference, and adherence of US cat owners prescribed topical fluralaner (Bravecto® Topical Solution for Cats).

Background: Fluralaner is a novel isoxazoline compound and the only systemically distributed ectoparasiticide approved in the United States for redosing at up to 12-week intervals for flea and tick control in cats. Other feline ectoparasiticides, including other systemic isoxazolines, are approved for redosing at monthly intervals. A survey developed in 2016 to assess the satisfaction, preference, and adherence of dog owners prescribed fluralaner as an ectoparasiticide with the treatment and veterinary flea and tick protection recommendations was adapted for completion by cat owners in the USA. Aim: The study objective was to use cat-owner survey data obtained at US veterinary practices to assess client satisfaction and utilization practices for fluralaner, and to evaluate owner adherence to current flea and tick control recommendations. Methods: US veterinary practices (n = 26) were asked to obtain completed surveys for up to 25 active clients who were currently treating their cats with a topical preparation of fluralaner for flea and tick control. Clients who had previously used flea and tick products for cats other than fluralaner were enrolled in the study. Participating cat owners completed an 11-question survey on their satisfaction with, preference for, and adherence to treatment recommendations for topically applied fluralaner as a feline flea and tick control medication. Results: The average cat in this study had a mean (± SD) body weight of 5.1 (± 0.9) kg and was 7.1 (±1.4) years old. Most cats lived in a home versus an apartment and more than half spent some time outside. Satisfaction was assessed with a 5-point Likert scale, with nearly all cat owners (97%) indicating that they were satisfied or very satisfied with fluralaner. Most of them (66%) had previously used other monthly flea and tick products for cats. Owners were not excluded if they had previously used a canine flea and tick product. The extended dosing interval up to 12 weeks was the most frequently selected benefit of fluralaner. Nearly 9 out of 10 respondents indicated they readministered fluralaner mostly on time or delayed by a few days, and most said they were more likely to give a repeat dose of fluralaner at the recommended redosing interval compared to monthly products. 87% of the responding cat owners preferred topical fluralaner over the monthly flea and tick products they had used. Conclusion: The extended dosing interval of up to 12 weeks was the leading preference factor and the key driver of user satisfaction with fluralaner leading to improved adherence to redosing recommendations. Cat owners said they were more likely to administer fluralaner at the recommended redosing interval compared to monthly products, indicating that less frequent redosing contributes to improved adherence.

Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against adult cat flea Ctenocephalides felis and flea egg production in cats.

Esafoxolaner, a purified enantiomer of afoxolaner with insecticidal and acaricidal properties, is combined with eprinomectin and praziquantel in NexGard® Combo, a novel topical endectoparasiticide formulation for cats. The efficacy of this novel formulation against adult and immature stages of Ctenocephalides felis fleas was tested in four experimental studies. Two studies were designed to test adulticide efficacy, one to test inhibition of immature stages, and one to test both adulticide efficacy and inhibition of immature stages. In each study, cats were randomly allocated to a placebo control group or to a novel formulation group treated once at the minimum recommended dose. Cats were experimentally infested weekly for one to two months with unfed C. felis originating from North America or Europe. For adulticide efficacy evaluations, live fleas were counted 24 h after treatment and after subsequent weekly infestations. For immature stages, flea eggs were collected and counted weekly for evaluation of egg production inhibition and incubated for larval hatching evaluation. In the three studies testing adult fleas, curative efficacies, 24 h after treatment, were 92.1%, 98.3% and 99.7%; preventive weekly efficacies, 24 h after weekly infestations, remained higher than 95.5% for at least one month. In the two studies testing immature stages, egg production and larval hatching was significantly reduced for at least one month. These studies provide robust evidence of efficacy of the novel formulation against experimental adult flea infestations and for the prevention of environmental contamination by immature flea stages, for at least one month.

TITLE: Efficacité d'une nouvelle association topique d'esafoxolaner, d'éprinomectine et de praziquantel contre la puce du chat adulte Ctenocephalides felis et la production d'œufs de puce chez le chat. ABSTRACT: L'esafoxolaner, un énantiomère purifié de l'afoxolaner aux propriétés insecticides et acaricides, est associé à l'éprinomectine et au praziquantel dans NexGard® Combo, une nouvelle formulation endectoparasiticide topique pour chats. L'efficacité de cette nouvelle formulation contre les stades adultes et immatures des puces Ctenocephalides felis a été testée dans quatre études expérimentales. Deux études ont été conçues pour tester l'efficacité des adulticides, une pour tester l'inhibition des stades immatures et une pour tester à la fois l'efficacité des adulticides et l'inhibition des stades immatures. Dans chaque étude, les chats ont été répartis au hasard dans un groupe témoin placebo ou dans un groupe de formulation traité une fois par la nouvelle formulation à la dose minimale recommandée. Des chats ont été expérimentalement infestés chaque semaine pendant un à deux mois par des C. felis non nourris provenant d'Amérique du Nord ou d'Europe. Pour les évaluations de l'efficacité des adulticides, les puces vivantes ont été comptées 24 heures après le traitement et après les infestations hebdomadaires suivantes. Pour les stades immatures, les œufs de puces ont été collectés et comptés chaque semaine pour l'évaluation de l'inhibition de la production d'œufs, et incubés pour l'évaluation de l'éclosion des larves. Dans les trois études testant les puces adultes, les efficacités curatives, 24 heures après le traitement, étaient de 92,1 %, 98,3 % et 99,7 %, et les efficacités hebdomadaires préventives, 24 heures après les infestations hebdomadaires, sont restées supérieures à 95,5 % pendant au moins un mois. Dans les deux études testant les stades immatures, la production d'œufs et l'éclosion des larves ont été considérablement réduites pendant au moins un mois. Ces études fournissent des preuves solides de l'efficacité de la nouvelle formulation contre les infestations expérimentales de puces adultes et pour la prévention de la contamination environnementale par les stades de puces immatures, pendant au moins un mois.

Efficacy of lotilaner (Credelio™) against experimentally induced infestations of the adult cat flea, Ctenocephalides felis, and flea eggs following oral administration to cats.

BACKGROUND: Credelio™ (lotilaner; Elanco) is indicated for the treatment of flea and tick infestations on cats at a recommended lotilaner dose rate of 6-24 mg/kg. This study evaluated the efficacy and safety of lotilaner following a single oral administration to cats for the treatment and prevention of adult Ctenocephalides felis fleas and flea egg production under laboratory conditions. METHODS: Two treatment groups of ten cats each were used in this study. One group was treated with lotilaner at a dose rate of 6-9 mg/kg on Day 0 and the other group served as the control group. Each cat was infested with 100 unfed adult fleas on days -1, 6, 13, 20 and 29. At 24 h post-treatment or post-infestation, each cat was combed to remove and count adult live fleas. At each time point, flea eggs were also collected and counted from under each cat cage. RESULTS: Following a single oral administration of lotilaner at a minimum dose rate of 6 mg/kg (range 6.00-8.57 mg/kg), the lotilaner group displayed 100%, 100%, 99.9%, 99.9% and 99.8% efficacy against adult live flea counts as compared to the control group on Days 1, 7, 14, 21 and 30, respectively. At each time point, adult flea counts from the lotilaner-treated cats were significantly lower (P < 0.0001) than from the control group. A mean flea egg count of 22.6 in the lotilaner-treated cats (compared to 441.7 in the control animals) was observed 24 h post-treatment. No eggs were present from any of the treated cats on Days 7, 14 and 30 and a single egg was detected on a single treated cat on Day 21. One adverse event (regurgitated food) was observed during the study in one treated cat approximately 1 h after dosing. CONCLUSIONS: Lotilaner was well tolerated; only one adverse event was observed in the treated group. Virtually all adult fleas were killed within 24 h post-treatment or post-infestation in cats treated with a single dose of lotilaner as compared to the control group, thus significantly reducing the number of flea eggs being produced for 30 days after treatment.

Fipronil Pellets Reduce Flea Abundance on Black-Tailed Prairie Dogs: Potential Tool for Plague Management and Black-Footed Ferret Conservation.

In western North America, sylvatic plague (a flea-borne disease) poses a significant risk to endangered black-footed ferrets (Mustela nigripes) and their primary prey, prairie dogs (Cynomys spp.). Pulicides (flea-killing agents) can be used to suppress fleas and thereby manage plague. In South Dakota, US, we tested edible "FipBit" pellets, each containing 0.84 mg fipronil, on free-living black-tailed prairie dogs (Cynomys ludivicianus). FipBits were applied along transects at 125 per ha and nearly eliminated fleas for 2 mo. From 9-14 mo post-treatment, we found only 10 fleas on FipBit sites versus 1,266 fleas on nontreated sites. This degree and duration of flea control should suppress plague transmission. FipBits are effective, inexpensive, and easily distributed but require federal approval for operational use.

'We should continue to recommend year-round flea protection for cats and dogs'.

Ian Wright argues that although there are environmental concerns regarding 'blanket' flea treatment of cats and dogs, without this measure pet owners would be at risk of potentially developing bartonellosis.

Flea and tick treatment satisfaction, preference, and adherence of dog owners in the United States, United Kingdom, and Australia who treated their dog with fluralaner.

Background: An extended duration flea and tick medication of the isoxazoline class (fluralaner) was introduced in 2014 in the United States and other countries. A survey was developed in 2016 to gauge dog owner adherence with veterinary recommendations around the administration of preventive flea and tick medications. Current fluralaner-using dog owners were also asked to compare their experience with opinions on monthly flea and tick products. Aim: To survey dog owners who were current users of fluralaner on their opinions, experiences, and attitudes around the administration of flea and tick medications to their dogs in light of current veterinarian recommendations. Methods: Dog owners in the United States (US), United Kingdom (UK), and Australia that gave fluralaner oral chews to their dogs were asked to compare their experience using fluralaner (12-week dosing) and monthly flea and tick medications. The survey responses of dog owners in the UK and Australia were compared against responses to a similar survey conducted in the US in 2017. Surveys were completed by dog owners who were in the clinic for any reason other than a sickness visit. Additionally, veterinarians that prescribed fluralaner from all three countries provided their annual flea and tick treatment recommendation for dogs. Results: A sample of veterinarians from the US, UK, and Australia that prescribe fluralaner recommend that dog owners obtain approximately 12 months of flea protection per year and 9-12 months of tick protection per year. A variable proportion of owners (22%-90%) reported that their dog participates in outdoor and social activities associated with an increased flea and tick exposure risk. A similarly variable proportion of owners reported prior experience of finding fleas (24%-50%) or ticks (18%-35%) on their dogs. All participating owners treated their dogs currently with fluralaner and most (68%-77%) had previously treated their dog with monthly flea and tick products. The convenience of 12-week dosing and less frequent dosing were the most frequently identified product qualities associated with their choice of an extended effect flea and tick treatment. Conclusion: Most veterinarians surveyed in this survey recommended year-round use of a flea and tick medication for dogs in the US, UK, and Australia. Dog owners recalled the veterinary recommendation for flea and tick prevention as 8-10 months per year. Most dog owners from the clinics in the US, UK, and Australia had used shorter-acting (monthly) flea/tick medications previously. The majority of those who currently gave fluralaner doses to their dogs were "satisfied" or "very satisfied" with the extended duration flea and tick product. Preference for a 12-week duration medication over monthly re-treatment was also high (82%-92%) in all three countries and was associated with convenience.

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 a topical sarolaner-selamectin combination to control flea populations on naturally infested cats in private residences in West Central Florida.

Historic data show that home flea infestations can be managed by treating all animals on the premises with a highly effective flea control product. The use of effective products has also been shown to reduce pruritus and minimize dermatologic lesions in both cats and dogs. Therefore, an in-home study was conducted in West Central Florida USA to evaluate the efficacy of a topically applied selamectin-sarolaner formulation to control fleas in naturally infested cats over a 12-week period. Thirty-seven cats in 21 households were treated once monthly with the selamectin-sarolaner topical solution. In the topical fluralaner treatment (positive control) group, forty-three cats in 20 households were treated once on day 0. A combined total of thirty dogs in both groups were treated once monthly with oral sarolaner. Fleas on cats were counted by flea combing, fleas on dogs were counted using visual area counts and fleas in the indoor premises were assessed using intermittent-light flea traps. Blinded-assessments of feline dermatologic lesions (modified-SCORFAD) were conducted monthly by a boarded-dermatologist and pruritus severity was evaluated by pet owners. Three consecutive monthly treatments of selamectin-sarolaner reduced flea populations on cats by 96.3 % within 7 days and by 100% from week 6 to the end of the 12-week study. The topical application of fluralaner reduced flea populations by 98.1 % within 7 days and efficacy reached 100% by week 12. At the end of the study, fleas were completely eradicated (from cats, dogs and homes) in every home regardless of treatment group. Owner reported cat pruritus was reduced by > 87 % in both treatment groups by week 12. Significant improvements in dermatologic lesion scores (> 81 %) were achieved by both products by the end of the study. Monthly applications of topical selamectin-sarolaner or topical fluralaner to cats living in the heavy flea challenge environment of West Central Florida USA were effective in eradicating flea infestations, reducing pruritus and improving dermatologic lesions.

Survey of canine use and safety of isoxazoline parasiticides.

A veterinarian and pet owner survey (Project Jake) examined the use and safety of isoxazoline parasiticides given to dogs. Data were received during August 1-31, 2018 from a total of 2,751 survey responses. Forty-two percent (1,157) reported no flea treatment or adverse events (AE), while 58% (1594) had been treated with some parasiticide for flea control, and of those that received a parasiticide, the majority, or 83% (1,325), received an isooxazoline. When any flea treatment was given, AE were reported for 66.6% of respondents, with no apparent AE noted for 36.1%. Project Jake findings were compared to a retrospective analysis of publicly available Food and Drug Administration (FDA) and European Medicines Agency (EMA) reported AE. The number of total AE reported to FDA and EMA were comparable, although a 7 to 10 times higher occurrence of death and seizures was reported from the EMA or from outside the United States (US). Serious AE responses for death, seizures and neurological effects reported in our survey were higher than the FDA but moderately lower than the EMA reports. These sizable global data sets combined with this pre- and post-parasiticide administration survey indicated that isoxazoline neurotoxicity was not flea- and tick-specific. Post-marketing serious AE were much higher than in Investigational New Drug (IND) submissions. Although the labels have recently been updated, dogs, cats and their caregivers remain impacted by their use. These aggregate data reports support the need for continued cross-species studies and critical review of product labelling by regulatory agencies and manufacturers.

Laboratory studies evaluating the efficacy of a novel orally administered combination product containing sarolaner, moxidectin and pyrantel (Simparica Trio™) for the treatment and control of flea infestations on dogs.

BACKGROUND: Five studies were conducted to evaluate a novel oral combination tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™), for efficacy against induced flea infestations, speed of kill and effects on flea reproduction on dogs. METHODS: Based on pre-treatment flea counts, dogs were randomly allocated to treatment with a single, oral dose of either placebo or Simparica Trio™ at the minimum label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt) on Day 0. All dogs were infested with approximately 100 unfed, adult fleas (C. felis or C. canis) prior to treatment and weekly for 5 weeks post-treatment. In Studies 1, 2 and 3, the number of viable fleas were comb-counted at 24 h after treatment and after each weekly infestation; Study 2 also included groups treated with tablets containing sarolaner-alone (1.2 mg/kg), moxidectin-alone (24 µg/kg) or pyrantel-alone (5 mg/kg). In Study 4, flea counts were conducted at 3, 4, 8 and 12 h after treatment and subsequent weekly infestations to establish speed of kill. In Study 5 (flea reproduction), dogs were housed in an enclosure designed to facilitate collection of flea eggs. RESULTS: Efficacy of Simparica Trio™ against C. felis was ≥ 99.7% and against C. canis was 100% at 24 h after treatment and after subsequent infestations for at least 35 days. Treatment with sarolaner-alone had similar efficacy to Simparica Trio™, while moxidectin-alone and pyrantel-alone were no different from placebo at most time points. In Study 4, significant flea killing started at 4 h after treatment; by 8 h after treatment, all treated dogs were free of fleas. Following weekly re-infestation, the combination product reduced fleas by ≥ 97.8% within 12 h for 28 days. Simparica Trio™ reduced flea egg-laying by 100% for 35 days. No treatment-related adverse reactions occurred in any study. CONCLUSIONS: A single dose of Simparica Trio™ at the recommended minimum dose provided highly efficacious and rapid treatment within 4 h of existing flea infestations and persistent control of fleas on dogs for 5 weeks. The efficacy against fleas resulted in 100% prevention of flea reproduction for over a month following a single oral dose.