Current perspectives and difficulties in the design of acaricides and repellents from plant-derived compounds for tick control.

Ticks and tick-borne diseases have gained increasing attention in recent years due to their impact on public health and significant losses in livestock production. The use of synthetic compounds for tick control is becoming problematic, mainly due to the resistance to commercially available products as well as their toxicity. Therefore, new alternative control methods are required. For this purpose, plant-derived extracts may be considered as effective repellents and/or acaricides. The present literature review focuses on studies evaluating the acaricidal and repellent activity of plant-derived extracts and plant secondary metabolites. We also noted recent advances in protein-ligand-docking simulation to examine the possible toxic effect of natural chemical compounds on ticks. In conclusion, plant-derived repellents/acaricides can be effective against ticks, especially in rural areas and livestock farms.

Developing attractants and repellents for ticks: promises and challenges.

Historically, some of the most effective tools to counter vector-borne diseases have been those directed against the vectors. Ticks are undergoing a population explosion as evidenced by the recent expansion of their distribution range. Tick control has traditionally relied heavily on pesticides. However, sustained use of acaricides is resulting in resistant tick populations. Multipronged management strategies that build and expand upon innovative control methods are sorely needed. Behavior-modifying chemicals, referred to as semiochemicals, such as pheromones and repellents, offer a first line of personal protection against ticks. We review the current understanding of tick semiochemicals, and how such understanding is leading to the identification of novel chemistries that are effective and safe.

Lyme disease transmission by severely impaired ticks.

It has been demonstrated that impairing protein synthesis using drugs targeted against tRNA amino acid synthetases presents a promising strategy for the treatment of a wide variety of parasitic diseases, including malaria and toxoplasmosis. This is the first study evaluating tRNA synthetases as potential drug targets in ticks. RNAi knock-down of all tested tRNA synthetases had a strong deleterious phenotype on Ixodes ricinus feeding. Our data indicate that tRNA synthetases represent attractive, anti-tick targets warranting the design of selective inhibitors. Further, we tested whether these severely impaired ticks were capable of transmitting Borrelia afzelii spirochaetes. Interestingly, biologically handicapped I. ricinus nymphs transmitted B. afzelii in a manner quantitatively sufficient to develop a systemic infection in mice. These data suggest that initial blood-feeding, despite the incapability of ticks to fully feed and salivate, is sufficient for activating B. afzelii from a dormant to an infectious mode, enabling transmission and dissemination in host tissues.

Novel ß-Cyclodextrin and Catnip Essential Oil Inclusion Complex and Its Tick Repellent Properties.

Cyclodextrin inclusion complexes have been successfully used to encapsulate essential oils, improving their physicochemical properties and pharmacological effects. Besides being well-known for its effects on cats and other felines, catnip (Nepeta cataria) essential oil demonstrates repellency against blood-feeding pests such as mosquitoes. This study evaluates the tick repellency of catnip oil alone and encapsulated in ß-cyclodextrin, prepared using the co-precipitation method at a 1:1 molar ratio. The physicochemical properties of this inclusion complex were characterized using GC-FID for encapsulation efficiency and yield and SPME/GC-MS for volatile emission. Qualitative assessment of complex formation was done by UV-Vis, FT-IR, 1H NMR, and SEM analyses. Catnip oil at 5% (v/v) demonstrated significant tick repellency over time, being comparable to DEET as used in commercial products. The prepared [catnip: ß-CD] inclusion complex exerted significant tick repellency at lower concentration of the essential oil (equivalent of 1% v/v). The inclusion complex showed that the release of the active ingredient was consistent after 6 h, which could improve the effective repellent duration. These results demonstrated the effective tick repellent activity of catnip essential oil and the successful synthesis of the inclusion complex, suggesting that ß-CDs are promising carriers to improve catnip oil properties and to expand its use in repellent formulations for tick management.

Translational biotechnology for the control of ticks and tick-borne diseases.

Ticks and tick-borne diseases (TBD) represent a challenge for human and animal health worldwide. Climate change, distribution of tick hosts, and ecological and anthropogenically-induced changes contribute to the geographic expansion of ticks and tick-borne pathogens. Traditional control methods are based on the use of acaricides to reduce tick infestations, but vaccines represent a more effective, sustainable and environmentally sound approach for the control of ticks and TBD. Recent application of omics technologies to the study of the mechanisms involved in tick-host-pathogen interactions have advanced the characterization of molecular mechanisms involved in TBD and the identification of candidate vaccine protective antigens. However, as discussed in this opinion paper, translational biotechnology may translate into novel interventions required to advance in addressing the challenge that ticks and TBD represent for world health and economy.

Analysis of gaps in feline ectoparasiticide purchases from veterinary clinics in the United States.

BACKGROUND: The study objective was to examine cat owner ectoparasiticide purchases in the United States and estimate the impact of purchase gaps on timely ectoparasite protection administration. These purchase gaps lead to periods of time when cats are unprotected from ectoparasites. METHODS: Ectoparasiticide purchase transactions for individual cats from 671 U.S. veterinary clinics from January 1, 2017 through June 30, 2019 were evaluated to determine time "gaps" between doses of ectoparasiticides purchased in a defined 12-month period. Ectoparasiticides examined were topically applied products that contained fluralaner, fipronil/(S)-methoprene/pyriproxyfen, imidacloprid/pyriproxyfen or selamectin as active ingredients. The duration of protection following administration of one dose was 8-12 weeks for the fluralaner-containing product and one month for the other products. RESULTS: Ectoparasiticide purchase records were obtained from 114,853 cat owners and analysis found that most owners bought ≤ 6 months of protection during the year, with 61-75% (depending on the product) purchasing just 1-3 months of protection. The size of the average purchase gap was determined for all dose combinations out to 12 months of protection (5-7 doses for fluralaner and 12 doses for the other three products dosed monthly. The largest gaps occurred between the first and second doses and the second and third doses. Average purchase gaps for the four different products between doses 1 and 2 ranged from 11.2 to 13.9 weeks and between doses 2 and 3 ranged from 7.7 to 12.2 weeks. The fraction of purchases separated by gaps and the average length of the gap tended to decrease with increasing number of doses purchased. Owners purchasing the 8 to 12-week duration product containing fluralaner provided ectoparasite protection ("doses plus gap period") for a larger proportion of each 2-dose period compared with owners purchasing products administered monthly. CONCLUSIONS: When cat owners purchase flea and tick medication, gaps between subsequent purchases reduces the proportion of time ectoparasite protection can be provided. The duration of the gap between doses has an impact on the effectiveness of flea/tick medication because it inserts a period without flea and tick protection between doses of flea and tick medication. The gaps between purchases were shorter and the period of ectoparasite protection was larger for owners purchasing a 12-week product than for owners purchasing a monthly product.

A knowledge, attitudes, and practices study on ticks and tick-borne diseases in cattle among farmers in a selected area of eastern Bhutan.

Livestock farming plays an important role in supporting the livelihood of resource-poor subsistence farmers in Bhutan. However, ticks and tick-borne diseases (TBDs) are one of the major constraints to livestock farming due to their negative effect on health and production. To date, no study has been conducted in Bhutan to assess farmers' knowledge, attitude, and practices (KAP) about ticks and TBDs in cattle, although such information is essential in ensuring the development and adoption of effective prevention and control measures. Therefore, a KAP survey was conducted among 246 cattle owners in the Samkhar sub-district of eastern Bhutan in June 2019, using a structured questionnaire. Based on our scoring criteria, 52% [95%CI: 45.5-58.4] had adequate knowledge about ticks as potential vectors of diseases. Logistic regression analysis showed that the individuals who practiced a stall-feeding system of cattle rearing were 2.8 times [OR = 2.8 (95%CI: 1.66-4.78)] more likely to have adequate knowledge than others. Sixty-eight percent [95%CI: 62.5-74.4] had a favorable attitude toward tick prevention and control programs. Men were 1.95 times [OR = 1.95 (95%CI: 1.09-3.55)] more likely to have a favorable attitude than women, and the individuals who practiced a stall-feeding system were 2.59 times [OR = 2.59 95%CI: 1.45-4.78)] more likely to have a favorable attitude than others, after adjusting for the effect of other variables in the model. Overall, only 38% [95%CI 32.5-45] of the respondents reported tick infestation as one of the most important animal health problems, but 100% reported using acaricides to control ticks in cattle. Despite a high level of acaricide usage, the level of knowledge was low among the farmers interviewed. Findings from this study underline the importance of considering identified knowledge gaps and initiating education efforts to improve the adoption of effective tick prevention and control measures among farmers.

The Effect of Long-lasting Permethrin Impregnated Socks on Tick Bite in Korea.

BACKGROUND: The risk of tick-borne diseases is decreased by increasing awareness and knowledge through prevention education. The aim of the present study was to evaluate the effect of long-lasting permethrin impregnated (LLPI) socks for tick bites. METHODS: A randomized open label study was conducted to determine the effectiveness of LLPI socks for prevention of tick bites among 367 adults living in a rural area. Participants completed questionnaires at the start of follow-up (July 2014) and at the end of follow-up (December 2014), and tick bites were reported. RESULTS: A total of 332 subjects completed the follow-up survey. The tick bite rate of the two groups was not significantly different (3.6% vs. 3.1%). But the tick bite rate of lower extremities of subjects wearing LLPI socks was significantly lower compared to that of subjects wearing general socks. CONCLUSION: The tick bite rate was not different between the two groups, but the tick bite rate of lower extremities of LLPI was significantly lower than general groups. Further study is needed to investigate the effect of LLPI clothes with larger populations.

Toxicity of essential oils obtained from Juniperus thurifera var. africana and Mentha suaveolens subsp. timija chemotypes against pre-adult stages of Hyalomma aegyptium tick (Acari: Ixodidae).

This experiment was undertaken to compare the acaricidal activity of two essential oil chemotypes obtained from Mint Timija (Mentha suaveolens subsp. timija (Briq.) Harley) and Incense Juniper (Juniperus thurifera var. africana Maire) against immature stages of Hyalomma aegyptium ticks. The results showed that both chemotypes obtained from the two species presented interesting acaricidal activity. The pulegone and menthone-rich chemotype of Mint Timija (CM1) presented the highest toxic activity, particularly against eggs (LD50 = 17.931 and LD90 = 36.547 ppm) and larvae (LD50 = 0.03 and LD90 = 2.29 ppm). While the piperitone-rich Mint Timija EO (CM2) presented the weakest activity (LD50 = 51.134 and LD90 = 83.663 ppm for eggs, LD50 = 7.84 and LD90 = 21.03 ppm for larvae). Regarding Incense Juniper, the two chemotypes presented relatively moderate activity, with that of sabinene-rich oil (CJ2) being the most effective against eggs (LD50 = 22.293 and LD90 = 53.112 ppm).

Adherence to veterinary recommendations for ectoparasiticides purchased by cat owners in the USA.

BACKGROUND: Safe and effective flea and tick treatment options for cats are important in companion animal practice because of feline ectoparasite infestation prevalence and the potential for parasitic disease transmission. Retrospective cat owner purchasing transactions at United States of America (USA) veterinary clinics were obtained for three topical feline flea and tick ectoparasiticides. One medication, fluralaner, had a 12-week redosing interval, while two other medications (fipronil/s-methoprene/pyriproxyfen; imidacloprid/pyriproxyfen) were approved for monthly redosing. The annual number of doses purchased by cat owners was determined for each of the three medications and then compared between medications. The objective was to evaluate whether 12-week retreatment intervals resulted in a different duration of coverage compared to monthly treatments for ectoparasiticide products. METHODS: Study results were obtained by analyzing the transactional records from a commercial database derived from veterinary practice management software. The study database consisted of cat owner purchasing records from January 2017 through June 2019 from 671 veterinary practices representing 41,630 cats. RESULTS: Cat owners purchased an average of 1.5 doses of fluralaner per year which, based on a 12-week redosing interval, provides 4.2 months of treatment coverage. Cat owners who used monthly flea and tick medications respectively purchased 3.6 months (fipronil/s-methoprene/pyriproxyfen combination) and 2.8 months (imidacloprid/pyriproxyfen) annually of each of the two medications. Average yearly cat owner purchases of fluralaner provide a significantly longer duration of coverage than for cat owners purchasing fipronil/s-methoprene/pyriproxyfen (17% more) or imidacloprid/pyriproxyfen (50% more). CONCLUSIONS: Cat owners who obtained a flea and tick treatment with a 12-week redosing interval (fluralaner) protected their cats for up to 17% or 50% longer duration each year, respectively, compared to the duration of protection obtained by cat owners who used a medication re-dosed monthly. Cat owners should increase their duration of flea and tick coverage to come closer to achieving veterinary recommendations.

Botanical acaricides induced morphophysiological changes of reproductive and salivary glands in tick: A mini-review.

Ticks are obligate hematophagous ectoparasites and important vectors of several pathogens of medical and veterinary significance, in addition to economic losses associated with their infestation. The primary method for the current control of tick is the use of synthetic acaricides, and many studies have focused on the tick control efficacy associated with the use of synthetic acaricides. However, the intensive use of these compounds has environmental and public health implications, in addition to the development of resistant tick populations. Over the years, studies have demonstrated the great potential of botanicals as an effective alternative in tick control. Most of the reviews on the acaricidal activity of botanicals focused on the effects relating to the development, reproduction, and mortality rate of ticks. Besides this acaricidal activity, botanicals can also affect the morphophysiology of the reproductive organs and the salivary glands that are important for tick procreation and survival. Effects relating to histopathological and cell ultra-structural alterations caused by botanical acaricides can be determined through microscopy techniques. Hence, the present mini-review focuses on studies dealing with morphophysiology changes of the reproductive system and the salivary gland of ticks exposed to botanical acaricides, with a view of expanding our knowledge for the future integrative application of botanical acaricides in tick control.

Chemical composition and acaricidal activity of Ocotea notata (Lauraceae), an endemic species from Brazil, against the cattle tick Rhipicephalus microplus / Composición química y actividad acaricida de Ocotea notata (Lauraceae), una especie endémica de Brasil, contra la garrapata del ganado Rhipicephalus microplus

Rhipicephalus microplus, is one parasites that cause severe productivity losses in the cattle industry of Brazil and shows increasing resistance to conventional pesticides. This research aims to study the chemical composition, and acaricidal activity of the essential oil from Ocotea notata leaves, a brazilian endemic species, against R. microplus. The effect on R. microplus engorged adult females was evaluated using the immersion test. The oil reduced the survival by 90% after incubation for 15 days and there was 100% reduction for posture inhibition and reproductive capacity. These results suggest that the O. notata essential oil has activity on the R. microplus.

Rhipicephalus microplus, es un parásito que causa graves pérdidas de productividad en la industria ganadera de Brasil y muestra una creciente resistencia a los pesticidas convencionales. Esta investigación tiene como objetivo estudiar la composición química y la actividad acaricida del aceite esencial de las hojas de Ocotea notata, una especie endémica brasileña, contra R. microplus. El efecto sobre las hembras adultas engordadas de R. microplus se evaluó mediante la prueba de inmersión. El aceite redujo la supervivencia en 90% después de la incubación durante 15 días y hubo una reducción del 100% para la inhibición de la postura y la capacidad reproductiva. Estos resultados sugieren que el aceite esencial de O. notata tiene actividad contra R. microplus.

Immediate and persistent efficacy of sarolaner (Simparica™) against Haemaphysalis elliptica on dogs.

BACKGROUND: The southern African yellow dog tick, Haemaphysalis elliptica, occurs in eastern and southern Africa and adults infest domestic and wild carnivores. This tick species is also a vector of the highly virulent Babesia rossi pathogen, the causative agent of canine babesiosis in sub-Saharan Africa. Sustained high levels of efficacy of a parasiticide are not only important in protecting dogs against the direct effects of tick infestation, but also in reducing the risk of tick-borne diseases. Sarolaner (Simparica™ chewable tablets) has been reported to be effective against the major tick species infesting dogs in Europe and the USA, including representatives from the genera Amblyomma, Ixodes, Rhipicephalus and Dermacentor. Until now no efficacy evaluations have been reported against species of the genus Haemaphysalis. The objective of the study was to confirm the efficacy of a single 2 mg sarolaner/kg oral dose of Simparica™ against induced infestations with H. (R.) elliptica, an important parasite of dogs in southern Africa. METHODS: This blinded, randomised, single centre, placebo controlled efficacy study followed a parallel group design and was conducted on two groups consisting of eight purpose-bred dogs each. Animals were treated orally, once on Day 0, with either a placebo compound (Group 1) or Simparica™ (Group 2). Simparica™ was administered orally at a dose rate of 2 mg sarolaner/kg body weight. The dogs were infested with ticks on Days - 7, - 2, 5, 12, 19, 26 and 33, with removal counts conducted on Days - 5, 2, 7, 14, 21, 28 and 35. RESULTS: A single oral administration of Simparica™ (sarolaner) at a minimum dose of 2 mg/kg resulted in a 100% efficacy against existing infestations of H. (R.) elliptica on dogs and a 100% reduction in live ticks following weekly re-infestations for 35 days. Moreover, the immediate and persistent high levels of efficacy observed in this study for 35 days is consistent with those observed in previous studies against ticks in other genera. CONCLUSIONS: The efficacy of sarolaner (Simparica™), administered orally to dogs at the minimum label dose of 2.0 mg/kg, was demonstrated against existing and weekly re-infestations of H. (R.) elliptica for at least 5 weeks. Efficacy of 100% was achieved against existing infestations as well as weekly re-infestations.

The case for oxidative stress molecule involvement in the tick-pathogen interactions -an omics approach.

The blood-feeding behavior of ticks has resulted in them becoming one of the most important vectors of disease-causing pathogens. Ticks possess a well-developed innate immune system to counter invading pathogens. However, the coevolution of ticks with tick-borne pathogens has adapted these pathogens to the tick's physiology and immune response through several mechanisms including transcriptional regulation. The recent development in tick and tick-borne disease research greatly involved the "omics" approach. The omics approach takes a look en masse at the different genes, proteins, metabolomes, and the microbiome of the ticks that could be differentiated during pathogen infection. Data from this approach revealed that oxidative stress-related molecules in ticks are differentiated and possibly being exploited by the pathogens to evade the tick's immune response. In this study, we review and discuss transcriptomic and proteomic data for some oxidative stress molecules differentially expressed during pathogen infection. We also discuss metabolomics and microbiome data as well as functional genomics in order to provide insight into the tick-pathogen interaction.

Antiparasitic Properties of Cantharidin and the Blister Beetle Berberomeloe majalis (Coleoptera: Meloidae).

Cantharidin (CTD) is a toxic monoterpene produced by blister beetles (Fam. Meloidae) as a chemical defense against predators. Although CTD is highly poisonous to many predator species, some have evolved the ability to feed on poisonous Meloidae, or otherwise beneficially use blister beetles. Great Bustards, Otis tarda, eat CTD-containing Berberomeloe majalis blister beetles, and it has been hypothesized that beetle consumption by these birds reduces parasite load (a case of self-medication). We examined this hypothesis by testing diverse organisms against CTD and extracts of B. majalis hemolymph and bodies. Our results show that all three preparations (CTD and extracts of B. majalis) were toxic to a protozoan (Trichomonas vaginalis), a nematode (Meloidogyne javanica), two insects (Myzus persicae and Rhopalosiphum padi) and a tick (Hyalomma lusitanicum). This not only supports the anti-parasitic hypothesis for beetle consumption, but suggests potential new roles for CTD, under certain conditions.

Efficacy of a new topical formulation of selamectin plus sarolaner for the control of fleas and ticks infesting cats in Japan.

The efficacy of a single application of a new topical formulation containing selamectin plus sarolaner (Revolution® Plus / Stronghold® Plus, Zoetis) was evaluated against fleas and ticks infesting cats enrolled as veterinary patients in two field studies conducted in Japan and against Haemaphysalis longicornis ticks on cats in a laboratory study. In the laboratory study, sixteen cats were ranked based on pre-treatment tick counts and allocated randomly to treatment on Day 0 with either selamectin plus sarolaner or placebo. Cats were infested with adult H. longicornis on Days -2, 5, 12, 19, 26 and 33. Efficacy relative to placebo was based on live attached tick counts conducted 48 h after treatment and subsequent re-infestations. Selamectin plus sarolaner reduced live, attached H. longicornis counts by 96.4% within 48 h of treatment, and by ≥91.7% within 48 h of weekly re-infestation for 35 days, based on arithmetic means. In the field studies, 67 client-owned cats harboring six or more live fleas and 63 cats harboring four or more live attached ticks were enrolled to evaluate selamectin plus sarolaner for efficacy and safety compared with a registered product. Cats were allocated randomly to treatment with selamectin plus sarolaner or fipronil plus (S)-methoprene based on order of presentation. Treatment was administered once on Day 0 and efficacy was assessed by parasite counts conducted on Days 14 and 30 compared to the pre-treatment count. In the flea field study, live flea counts on Days 14 and 30 were reduced by 99.5% and 99.9% in the selamectin plus sarolaner group, and by 97.6% and 98.6% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Clinical signs typically associated with flea allergy dermatitis improved following treatment. In the tick field study, live tick counts on Days 14 and 30 were reduced by 97.5% and 97.7% in the selamectin plus sarolaner group, and by 91.5% and 93.4% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Selamectin plus sarolaner was determined to be non-inferior to fipronil plus (S)-methoprene in both field studies. There were no treatment-related adverse events in any study. A single topical dose of Revolution® Plus / Stronghold® Plus providing a minimum dosage of 6.0 mg/kg selamectin and 1.0 mg/kg sarolaner was confirmed to be effective against H. longicornis ticks on cats for one month and safe and effective in the treatment of fleas and ticks on cats enrolled as veterinary patients in Japan.

How rational drug use reduces trypanosome infections in cattle in chemo-resistance hot-spot villages of northern Togo.

The study assessed an integrated trypanosomosis control strategy in drug-resistant hotspot villages of northern Togo. This strategy comprised (i) rational trypanocidal drug use in symptomatic cattle, (ii) vectors and ticks control by targeted bi-monthly insecticidal spraying of the lower body parts of cattle and (iii) strategic deworming with Albendazole in the beginning and the end of the rainy season. The program was implemented between June 2014 and October 2015 in four villages in northern Togo, which had been previously identified as drug resistant hotspots for diminazene diaceturate (DA) and isometamidium chloride (ISM). The integrated control strategy was implemented in eight cattle herds at risk of the disease from two villages. Twelve herds from two other villages served as controls where trypanosomosis management and deworming remained under control of the farmers. Trypanocidal drug use during the study period was recorded by the intervention team based on the farmers' reports and own observations. Cattle herds were followed-up for trypanosomosis symptoms which were recorded at 3 to 4-month intervals, while extensive trypanosome diagnostics and recording of the packed cell volume were done before and after the intervention. Intervention herds had a significantly lower risk of trypanosome infection with a risk ratio of 0.18 (95% CI: 0.04, 0.91; p = 0.03), but no significant effect on mean packed cell volume was observed. However, trypanocidal treatments per animal per year were lower in intervention herds compared to control herds (0.3 vs 5 for DA and 0.8 vs 2 for ISM). This study demonstrates that the implementation of an integrated best-bet strategy leads to a reduced trypanosome prevalence under lowered trypanocidal use.

Effectiveness of deltamethrin-impregnated dog collars on the incidence of canine infection by Leishmania infantum: A large scale intervention study in an endemic area in Brazil.

To reduce morbidity and mortality caused by visceral leishmaniasis (VL), the Brazilian Visceral Leishmaniasis Control and Surveillance Program promotes the diagnosis and treatment of cases, vector control, euthanasia of seropositive dogs, and health education. Nevertheless, the effectiveness of these measures is questionable as they lead to little reduction in the transmission of the disease. Thus, the effectiveness of strategies such as insecticide-impregnated collars, spot-on insecticides, and immunization of dogs should be assessed. Herein, we evaluated the effectiveness of deltamethrin-impregnated collars on reducing the incidence of Leishmania infantum infection in dogs living in an endemic area of VL. An intervention study was conducted and a total 5,850 dogs were analyzed in baseline. Of these 3,742 seronegative dogs were divided into two groups: collared and uncollared (control). Dogs were followed for 12 months and three interventions were performed. The Cox regression model was used to evaluate the effectiveness of the collar. All analyzes were performed by Intention-to-treat and per-protocol. By intention-to-treat, the incidence rates of L. infantum infection were 7.5 and 7.9 in the collar group, and 6.5 and 13.2 per 1,000 dogs-months in the control group after 6 and 12 months, respectively. In the per-protocol analysis, the incidence rates in the control group were similar to those observed in the intention-to-treat analysis. In the collar group, the incidence rate was 5.1/1,000 dogs-months after 6 and 12 months. The effectiveness by intention-to-treat after adjustment by the multivariate Cox model was 48%. In the analysis per-protocol, the effectiveness increased to 63%. Although collar use was effective when it was evaluated by intention-to-treat, higher effectiveness was found in the per-protocol analysis after one year of follow-up. The data emphasize the importance of the uninterrupted use of deltamethrin-impregnated collars to increase protection against canine VL.

Dog owner flea/tick medication purchases in the USA.

BACKGROUND: Veterinary clinic transaction records from the USA were examined to determine dog owner purchase patterns for three prescription ectoparasiticides. In-clinic purchases of formulations of fluralaner (with 12-week duration per dose) were compared with dog owner purchases of afoxolaner and spinosad (both with 4 week duration per dose) in a population of 231,565 dogs over a 12 month period. Prior studies in human and animal medicine have suggested that patients more closely adhere to prescriber dosing recommendations when they receive a longer-duration medication. RESULTS: Veterinary clinic transaction records were examined for the period June 2014 through March 2017 using records from approximately 650 veterinary clinics. Ectoparasiticide purchase patterns were compared for two products (afoxalaner and spinosad) with monthly dosing and one product (fluralaner) with an extended (12 week) dosing interval. The average dog owner who obtained fluralaner purchased significantly more months of flea/tick protection (5.7 months) over the 12-month study period than the average dog owner that selected either afoxolaner (4.6 months) or spinosad (3.3 months). The proportion of dog owners who obtained only one dose of ectoparasiticide per 12-month period was 42% for fluralaner, 30% for afoxolaner and 37% for spinosad. The proportion of dog owners who obtained 2 doses or less per 12-month period was 67% for fluralaner, 52% for afoxoalaner and 67% for spinosad. Owners that obtained fluralaner were significantly more likely to obtain 7.0-12.0 months of flea and tick protection and significantly less likely to purchase 1.0-6.9 months compared with dog owners who purchased afoxolaner or spinosad. CONCLUSIONS: Dog owners who obtained a flea and tick medication with a longer duration of action acquired significantly more months of protection in a year than dog owners who obtained shorter duration (1 month) products. Dog owners were better able to adhere to veterinary recommendations on ectoparasites control with a longer-acting flea/tick medication.

Larvicidal potential of piperovatine in the control of cattle tick.

Rhipicephalus (Boophilus) microplus is one of the most important ectoparasites in cattle breeding worldwide, causing direct and indirect losses to animals and producers. Chemical acaricides are utilized in the control of cattle tick and the increase in the development of resistance by ectoparasites makes new alternative necessary. Therefore, research studies have been carried out using bioactive molecules that are quickly degraded and that reduce poisoning to appliers and non-target organisms, environmental contamination and development of resistance. Thus, this study aimed to isolate piperovatine from the roots of Piper corcovadensis, a native species to Brazil, and to evaluate the larvicidal activity against Rhipicephalus (Boophilus) microplus by larval packet test and in ex situ in an open environment. Piperovatine was isolated by classical column chromatography, and identified by 1H and 13C NMR. The lethal concentration (LC) of piperovatine that killed 50% (LC50) and 99% (LC99) of the larvae was determined by Probit analysis. The results indicated LC50 5.17 and LC99 25.41 µg/mL. LC99 was tested in ex situ in an open environment, and an efficiency of 96.63% was found, indicating that piperovatine kept the larvicidal action determined in in vitro test and in open environment. Therefore, this study shows new perspectives to develop products that can be applied in natural conditions to control this ectoparasite.