Efficacy of a topical combination of esafoxolaner, eprinomectin and praziquantel against Amblyomma maculatum infestations in cats.

Amblyomma maculatum, the Gulf Coast tick, infests a wide range of vertebrate species including livestock, dogs, cats, and humans. It is a species of significant veterinary and public health importance, especially as a vector of diseases, for instance American canine hepatozoonosis or tidewater spotted fever. An experimental study was conducted to evaluate the efficacy of NexGard® Combo, a topical endectoparasiticide product for cats combining eprinomectin, praziquantel and esafoxolaner, against induced infestations of A. maculatum in cats. This Good Clinical Practice (GCP) study used a randomized, negative controlled, masked design. Ten cats were allocated to an untreated group and ten to a treated group, dosed once on Day 0 at the minimum label dose. On Days -2, 7, 14, 21, 28, 35, and 42, cats were infested with ~50 unfed adult A. maculatum. On Days 3, 10, 17, 24, 31, 38, and 45, i.e., 72 h after treatment and subsequent infestations, ticks were removed, counted and the numbers of live attached tick in each group were used for efficacy calculations. At each time-point, all untreated cats were adequately infested, demonstrating a vigorous tick population and an adequate study model. The curative efficacy after a single application against existing tick infestation, 72 h after treatment, was 98.7%. The preventive efficacy, 72 h after weekly infestations, over the following five weeks ranged from 93.8% to 99.4%.

Title: Efficacité d'une association topique d'esafoxolaner, d'éprinomectine et de praziquantel contre les infestations par Amblyomma maculatum chez le chat. Abstract: Amblyomma maculatum, la tique de la Gulf Coast, infeste un large éventail d'espèces de vertébrés, notamment le bétail, les chiens, les chats et les humains. Il s'agit d'une espèce d'importance significative en médecine vétérinaire et en santé publique, notamment en tant que vecteur de maladies, par exemple l'hépatozoonose canine américaine ou la fièvre pourprée des marées. Une étude expérimentale a été menée pour évaluer l'efficacité de NexGard® Combo, un produit endectoparasiticide topique pour chats associant éprinomectine, praziquantel et esafoxolaner, contre les infestations par A. maculatum provoquées chez le chat. Cette étude de bonnes pratiques cliniques (BPC) a utilisé une conception randomisée, contrôlée négativement et masquée. Dix chats ont été répartis dans un groupe non traité et dix chats dans un groupe traité, traités une fois au jour 0 à la dose minimale indiquée sur l'étiquette. Aux jours −2, 7, 14, 21, 28, 35 et 42, les chats ont été infestés par environ 50 A. maculatum adultes non nourris. Les jours 3, 10, 17, 24, 31, 38 et 45, c'est-à-dire 72 heures après le traitement et les infestations ultérieures, les tiques ont été retirées, comptées et le nombre de tiques vivantes attachées dans chaque groupe a été utilisé pour les calculs d'efficacité. À chaque instant, tous les chats non traités étaient correctement infestés, démontrant une population de tiques vigoureuse et un modèle d'étude adéquat. L'efficacité curative après une seule application contre une infestation de tiques existante, 72 heures après le traitement, était de 98,7%. L'efficacité préventive, 72 heures après les infestations hebdomadaires, au cours des cinq semaines suivantes, variait entre 93,8% et 99,4%.

Evaluation of the efficacy of Simparica Trio® in the prevention of the transmission of Babesia canis by infected Dermacentor reticulatus to dogs.

BACKGROUND: Babesia canis is a clinically relevant vector-borne pathogen in dogs, and its presence is expanding. The efficacy of Simparica Trio® (Zoetis) in the prevention of B. canis transmission was evaluated at the minimum recommended label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel per kg bodyweight. METHODS: Twenty-four (24) dogs were randomly allocated to either a placebo-treated group or one of two treatment groups with Simparica Trio. Dogs were infested with B. canis-infected Dermacentor reticulatus ticks 21 or 28 days after treatment administration. Blood samples for antibody and DNA detection were collected from each dog prior to tick infestation until 28 days after infestation. A dog was defined as being B. canis positive if it tested positive by both an indirect immunofluorescence assay (IFA) and PCR at any time during the study. RESULTS: No treatment-related adverse reactions were recorded during the study. All placebo-treated animals displayed clinical signs due to babesiosis and tested positive on both IFA and PCR. None of the Simparica Trio-treated animals displayed any clinical symptoms or tested positive, resulting in a 100% efficacy in the prevention of canine babesiosis (P < 0.0001). CONCLUSIONS: A single treatment with Simparica Trio at the minimum recommended label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel per kg bodyweight prevents the transmission of B. canis by infected D. reticulatus to dogs for at least 28 days.

Aural hematoma in lambs associated with Otobius megnini (Ixodida: Argasidae) infestation.

In this report we described a case of aural hematomas in three lambs associated with Otobius megnini (Ixodida: Argasidae) infestation. From April to May 2021, five 3-month-old Hampshire cross lambs presented with unilateral aural hematomas. Upon otoscopic examination, engorged soft ticks (O. megnini) were observed in the external ear canals of three of the five lambs. The remaining two lambs had lesions consistent with infestation and were in a shared environment and deemed likely to have been infected. The treatment of all animals was based on the drainage of the serosanguinous fluid through an incision in the internal space of the ear pinna. Upon physical inspection of the entire flock (n = 310), O. megnini infestation was observed in one additional animal that did not have a hematoma. Following animal and environmental ectoparasiticide treatment with permethrin, no recurrences or additional cases of aural hematomas were observed in the flock in the following two-year period. To the authors' knowledge, this is the first description of aural hematomas in lambs associated with O. megnini infestation with successful recovery after surgery and off-label acaricide treatment.

Effective treatment of sarcoptic mange in an alpaca (Vicugna pacos) using fluralaner: a case report.

South American Camelids, including alpacas, have gained popularity in Europe as pets and prized wool sources. Skin health concerns, particularly mite infestations, have emerged as a notable problem in these animals. Sarcoptic mange can lead to severe itching, papules, and chronic symptoms such as alopecia, crusts, and emaciation if left untreated. This case report documents a 2-year-old female alpaca suffering from sarcoptic mange. Despite initial treatment with ivermectin, its condition worsened, leading to severe weight loss, abortion, and a continued presence of mites. Considering the lack of effective treatments for sarcoptic mange in alpacas and the unavailability of registered drugs for this species in Italy, fluralaner, a drug previously used in other animal species, has been administered orally at a dosage of 5 mg/kg. Within a week after the treatment with fluralaner, the patient exhibited significant improvement, including the resolution of itching, healing of skin lesions, and an increase in appetite. Follow-up skin scrapings confirmed the absence of mites, and the patient's condition continued to improve. Fluralaner demonstrated to be a highly effective and fast-acting treatment for sarcoptic mange in alpacas, offering potential economic benefits attributed to its single-dose administration.

Comparison of topical permethrin 5% vs. benzyl benzoate 25% treatment in scabies: a double-blinded randomized controlled trial.

BACKGROUND: Scabies is a pruritic parasitic infestation of the skin. High-income countries have reported an increasing incidence over the last few years. Studies have indicated a reduction in the sensitivity of scabies mites to the standard treatment of choice, topical permethrin 5%. OBJECTIVES: To evaluate in a head-to-head manner the efficacy of two topical scabicides [permethrin 5% and benzyl benzoate 25% (BB)] in the treatment of scabies using the same administration modality; and to address potential confounding factors such as incorrectly performed treatment and hygiene measures. METHODS: In total, 110 patients with dermoscopy-verified scabies infestation were enrolled and randomized into two equally sized groups in a double-blinded manner. Fifty-five received topical permethrin 5% and 55 received topical BB 25%, both for daily use over a period of three consecutive days. Treatment outcome was evaluated by dermoscopy at a 3-week follow-up visit. RESULTS: Treatment resulted in a dermoscopy-verified cure rate of 27% in the permethrin group and 87% in the BB group. The tolerability and safety profile of permethrin 5% cream was excellent, while the BB emulsion produced a burning sensation in 43% of patients. CONCLUSIONS: Topical permethrin demonstrated a lack of efficacy in the majority of scabies cases, whereas BB demonstrated an excellent cure rate and reasonable tolerability. Considering the reduced sensitivity of scabies mites to permethrin 5%, our results suggest that BB is an appropriate first-line therapy in the treatment of scabies.

Do combinations of fipronil, eugenol and carvacrol have synergistic effects against Rhipicephalus sanguineus?

The tick Rhipicephalus sanguineus is one of the main ectoparasites that affects dogs, causing direct and indirect damage to parasitized animals. Currently, infestation control is mainly carried out by using synthetic acaricidal drugs. However, a decrease in efficacy and an increase in resistance to the main therapeutic protocols against tick infestations have been increasingly reported and confirmed, a factor that has driven research into the potential acaricide activity of natural compounds, including in association with synthetic molecules. The aim of this work was to evaluate whether the combinations of fipronil (FIP) and eugenol (EUG), FIP and carvacrol (CAR), and EUG and CAR would have synergistic effects against immature and unfed adult stages of R. sanguineus through in vitro bioassays. Bioassays were carried out using the larval packet test (FAO 2004) adapted for nymphs and adults. The synergistic activity was explored by combining each solution, based on the estimated LC50, in a 1:1 ratio (FIP: EUG, FIP: CAR and EUG: CAR). CompuSyn software was used to evaluate the various pairwise combinations of FIP, EUG and CAR, checking if there was synergism or antagonism between them. FIP and EUG and FIP and CAR showed combination index (CIn) values above 1.45, indicating antagonism. The synergistic activity between EUG and CAR was verified against all unfed phases of R. sanguineus, since the CIn was below 0.70, a value that indicates synergism. The combination of fipronil with either eugenol or carvacrol presented antagonistic effects against R. sanguineus larvae. On the other hand, carvacrol and eugenol had excellent pharmacological synergism against all tick stages with mortality values in the range of 80 to 100%, including the adult stage, which is less susceptible than immature stages.

[Acaricidal therapy in chronic demodex blepharitis and meibomian gland dysfunctions]. / Akaritsidnoe lechebnoe vozdeistvie pri khronicheskom demodekoznom blefarite i disfunktsii meibomievykh zhelez.

PURPOSE: The study comparatively evaluates the effectiveness of various approaches to acaricidal treatment in patients with chronic demodex blepharitis and meibomian gland dysfunctions. MATERIAL AND METHODS: The study included 40 patients with chronic blepharitis (CB) of demodicosis etiology in conditions of meibomian gland dysfunction (MGD) and dry eye (DE). The 1st group of patients (20 people) received acaricidal treatment as part of therapeutic eyelid hygiene (TEH; 2 times a day) involving the use of «Blefarogel ochishchenie¼, «Blefarolosion¼, «Blefarogel forte¼ (contains sulfur and metronidazole). Acaricidal treatment in the patients of the 2nd group involved applications of a product containing metronidazole (2 times a day) without TEH. Control points: 1) at inclusion in the study; 2) after a course of therapy (45 days). Evaluation included: patient acarograms, symptoms and signs of CB (points); OSDI; tear film break-up time (TBUT, sec), severity of meibomian gland dysfunction (S-MGD, points). Statistical analysis: calculation of M±SD, Mann-Whitney, and Wilcoxon tests. RESULTS: Acaricidal treatment was effective in both groups (reduction in demodex population, which was more pronounced in the 1st group). Symptoms and signs of CB were significantly less pronounced in the patients of the 1st group after therapy. The patients of the 1st group showed a significant decrease in S-MGD, OSDI and an increase in TBUT, the 2nd group - a significant decrease in OSDI and an increase in TBUT at the second control point. The positive OSDI and TBUT trends were significantly more pronounced in the 1st group. CONCLUSION: Acaricidal treatment as part of TEH showed a significantly more pronounced reduction in demodex population, relief of CB symptoms and sign, OSDI decrease and TBUT increase, compared to the 2nd group. Apparently, this was associated with combined acaricidal effect and significant S-MGD decrease in the patients of the 1st group.

Essential oils and isolated compounds for tick control: advances beyond the laboratory.

BACKGROUND: Tick control is a worldwide challenge due to its resistance to acaricides. Essential oils (EOs) and isolated compounds (EOCs) are potential alternatives for tick control technologies. METHODS: A review with EOs and EOCs, under field and semi-field conditions, was performed based on Scopus, Web of Science and PubMed databases. Thirty-one studies published between 1991 and 2022 were selected. The search was performed using the following keywords: "essential oil" combined with "tick," "Ixodes," "Argas," "Rhipicephalus," "Amblyomma," "Hyalomma," "Dermacentor," "Haemaphysalis" and "Ornithodoros." The words "essential oil" and "tick" were searched in the singular and plural. RESULTS: The number of studies increased over the years. Brazil stands out with the largest number (51.6%) of publications. The most studied tick species were Rhipicephalus microplus (48.4%), Ixodes scapularis (19.4%), Amblyomma americanum and R. sanguineus sensu lato (9.7% each). Cattle (70%) and dogs (13%) were the main target animal species. Regarding the application of EOs/EOCs formulations, 74% of the studies were conducted with topical application (spray, pour-on, foam, drop) and 26% with environmental treatment (spray). Efficacy results are difficult to evaluate because of the lack of information on the methodology and standardization. The nanotechnology and combination with synthetic acaricides were reported as an alternative to enhance the efficacy of EOs/EOCs. No adverse reactions were observed in 86.6% of the studies evaluating EOs/EOCs clinical safety. Studies regarding toxicity in non-target species and residues are scarce. CONCLUSIONS: This article provides a comprehensive review on the use of EOs and EOCs to reduce tick infestations, in both the hosts and the environment. As future directions, we recommend the chemical characterization of EOs, methodology standardization, combination of EOs/EOCs with potential synergists, nanotechnology for new formulations and safety studies for target and non-target organisms, also considering the environmental friendliness.

Efficacy of a chewable tablet containing sarolaner, moxidectin, and pyrantel (Simparica Trio®) in the treatment of sarcoptic mange caused by Sarcoptes scabiei mite infestations in dogs.

BACKGROUND: Infestation with Sarcoptes scabiei in dogs is a debilitating disease if left untreated and is transmissible to humans. Two field studies were conducted to confirm the efficacy of orally administered sarolaner in combination with moxidectin and pyrantel (Simparica Trio®) in the treatment of sarcoptic mange in dogs. METHODS: Client-owned dogs with S. scabiei infestation were enrolled and received 2 monthly treatments. In the first, small-scale study, 12 dogs each were allocated randomly to treatment with either placebo or Simparica Trio®. Skin scrapings to detect live mites and assessment of clinical signs of sarcoptic mange were conducted on Days 0, 14, 30, 44, and 60. Efficacy was calculated based on the percent reduction in arithmetic mean live mite counts relative to placebo. In the second, large-scale study, 75 dogs were allocated randomly to treatment with Simparica Trio® and 37 to treatment with afoxolaner + milbemycin oxime (NexGard Spectra®). Skin scrapings to detect live mites and assessment of clinical signs of sarcoptic mange were conducted on Days 0, 14, 30, and 60. The parasitological cure rate (percentage of dogs without live mites) was determined and non-inferiority of Simparica Trio® to the control product was assessed. RESULTS: In the small-scale study, 2 monthly doses of Simparica Trio® resulted in a significant reduction (P ≤ 0.0050) in live S. scabiei mite numbers and provided a 99.2% reduction relative to placebo by Day 60. Clinical signs of sarcoptic mange improved throughout the study in Simparica Trio®-treated dogs. In the large-scale study, the parasitological cure rate on Days 30 and 60 was 97.3% and 100% in the Simparica Trio® group and 91.9% and 100% in the afoxolaner + milbemycin oxime group, respectively. The parasitological cure rate for Simparica Trio® was non-inferior to afoxolaner + milbemycin oxime at both time points. Clinical signs of sarcoptic mange improved throughout the study in both groups. CONCLUSIONS: Two-monthly doses of Simparica Trio® reduced S. scabiei mite counts by 99.2% relative to placebo in one study and eliminated S. scabiei mites in 100% of dogs in the second study, thus confirming that Simparica Trio® is highly effective in the treatment of sarcoptic mange in dogs caused by S. scabiei var. canis.

Comparison of the initial and residual speed of Ixodes scapularis kill on dogs treated with a single dose of Bravecto® Chew (25 mg/kg fluralaner) or Simparica TRIO® (1.2 mg/kg sarolaner, 24 µg/kg moxidectin, 5 mg/kg pyrantel).

BACKGROUND: Compliant ectoparasiticide product use is a comprehensive way to control ticks and reduce the risk of tick-borne pathogen transmission to dogs. Because the systemically acting isoxazoline ectoparasiticides require tick attachment for drug delivery, fast speed of kill is essential to minimize tick-borne pathogen transmission risk. METHODS: Dogs of satisfactory tick-carrying capacity were randomly allocated to treatment groups and administered, per label instructions, Bravecto® Chews (minimum 25 mg/kg fluralaner), Simparica TRIO® (minimum 1.2 mg/kg sarolaner, 24 µg/kg moxidectin, 5 mg/kg pyrantel), or no treatment. Dogs were infested with approximately 50 unfed adult (35 female, 15 male) Ixodes scapularis on Day -2, 21 and 28. Live tick counts were performed at 4, 8, 12 and 24 h post-treatment (Day 0) and post-infestation on Day 21 and 28. Tick control efficacy was determined by comparing live tick means for each product-treated group to the untreated control group and each other at all time points using a linear mixed model. The percent of dogs free of live ticks was analyzed using the Fisher's exact test for treatment group comparison. RESULTS: The untreated control group maintained adequate tick infestations throughout the study. Using geometric means, an existing I. scapularis infestation was controlled by 99.7% and 93.0% 12 h post-treatment and by 100% and 99.5% 24 h post-treatment, for Bravecto® and Simparica TRIO®-treated dogs, respectively. Ixodes scapularis infestations were controlled more quickly for Bravecto®- compared to Simparica TRIO®-treated dogs on Day 21 at 8 h (efficacy 74.0% vs. 0.0%, p = 0.003) and 12 h (efficacy 99.2% vs. 39.4%, p < 0.001) post-infestation and Day 28 at 8 h (efficacy 92.2% vs. 0.0%, p < 0.001) and 12 h (efficacy 99.6% vs. 27.7%, p < 0.001) post-infestation. On Day 28 post-treatment, the efficacy of Bravecto® and Simparica TRIO® to control a new I. scapularis infestation was 100% and 96.6%, respectively, by 24 h post-infestation. Of product-treated dogs, 100% of Bravecto®-treated dogs were free of live ticks by 24 h post-treatment or post-infestation. No treatment-related adverse reactions occurred during the study. CONCLUSIONS: Ixodes scapularis infestations are controlled more quickly 21 and 28 days post-treatment for dogs administered a single dose of Bravecto® compared to dogs administered a single dose of Simparica TRIO®.

Year-round efficacy of a single treatment of fluralaner injectable suspension (Bravecto QuantumTM) against repeated infestations with Ixodes holocyclus in dogs.

BACKGROUND: The longer the duration of protection of an acaricide against canine infestation with Ixodes holocyclus, the lower the risk of gaps in tick control programs that will place dogs at risk of potentially fatal tick-induced paralysis. Two studies investigated the duration of efficacy provided by a novel injectable suspension of fluralaner (Bravecto QuantumTM) against this tick species. METHODS: In both studies, 20 clinically healthy dogs were randomized to an untreated control group or to a group treated once, on Day 0, with the injectable fluralaner suspension (15 mg/kg). Dogs were infested with up to 25 unfed adult female I. holocyclus ticks on Day -1, during Weeks 1 and 2, and then at intervals no greater than approximately 3 months for the 13 months following treatment. Ticks were assessed in situ at 24 and 48 h and assessed and removed at 72 h following treatment and each subsequent infestation. Efficacy was determined by comparing arithmetic mean live tick (attached or free) counts in the treated group with the control group. RESULTS: The untreated control dogs maintained adequate infestations for efficacy evaluations at all assessment weeks, with mean tick counts ranging from 16.2 to 21.6 in Study 1 and 14.0 to 23.5 in Study 2. The efficacy of fluralaner injectable suspension against existing infestations, determined 72 h following treatment administration, was 64.1% in Study 1 and 42.7% in Study 2. Efficacy against post-treatment infestations in Study 1 ranged from 95.7 to 100% from Week 1 through Week 57; in Study 2 efficacy was 100% at every assessment from Week 1 through Week 57. No treatment-related adverse events were recorded in either study. CONCLUSION: The injectable fluralaner suspension was highly effective against I. holocyclus infestations of dogs from one week through 13 months following a single treatment. By placing treatment with the veterinarian, killing ticks within 72 h of attachment, and providing a full year of protection, fluralaner injectable suspension can help facilitate owner compliance with tick control treatment recommendations, thus reducing the risk of canine tick paralysis.

The most effective systemic treatment in dogs with sarcoptic mange: a critically appraised topic.

BACKGROUND: Sarcoptic mange is a common, pruritic parasitic skin disease of dogs. Due to its highly contagious character, it represents a potential veterinary and public health risk. Because of clinical similarity with other diseases, cross-antigenicity, and low sensitivity of available diagnostic methods, therapeutical trial is frequently used to confirm the disease. Considering the variety of available acaricidal molecules as well as the need to use the most effective treatment, the present paper reviews evidence comparing different types of systemic treatment of canine scabies. RESULTS: Analysis of the results showed that afoxolaner, fluralaner and sarolaner as well as several macrocyclic lactones such as selamectin, moxidectin and milbemycin oxime can lead to parasitological and clinical cure. CONCLUSION: The similarity in the clinical and parasitological efficacy of these substances enhances the need for comparative studies, which could allow the identification of the most efficacious product.

In vitro toxicity of combination of amitraz and carvacrol on Demodex canis.

Background: Canine generalized demodicosis is an inflammatory skin disease, which usually has time-consuming and frustrating treatments. Aim: The present study aimed to evaluate the acaricidal activity of carvacrol as a green drug and a combination of carvacrol and amitraz on Demodex canis mites and investigate mites' survival lifetime. Methods: Mite samples were collected from a dog affected by demodicosis and had been diagnosed with deep skin scrapings. The motility of mites was examined by using optical microscopy. Samples were tested with 5% of carvacrol, the combination of Carvacrol 5% + Amitraz 0.05%, Amitraz 0.05% as a positive control, and mineral oil as a negative control. The interval time between the adding the test solutions and the moment the last mite ceased was defined as the survival time in the samples and the killing times of mites in each group were compared with each other. Results: It was determined that after administration of a 5% concentration of carvacrol, lethal effects were faster than the combination solution of Carvacrol 5% + Amitraz 0.05%, and the survival times in the control groups were longer than in both treatment groups. Conclusion: Carvacrol, as one of the most important bioactive terpenes, had the most effective in vitro miticidal activity, and it seems that carvacrol alone or in combination with amitraz can be suggested as a possible therapy in the treatment of canine demodicosis.

Selective versus strategic control against Rhipicephalus microplus in cattle: A comparative analysis of efficacy, animal health, productivity, cost, and resistance management.

This study compared selective control versus strategic control against Rhipicephalus (Boophilus) microplus, under conditions of a real dairy farm. Strategic control requires that all animals be treated with acaricide at regular pre-determined intervals. Selective control only requires treatment of infested animals and only when they are at or above a pre-determined threshold. Tick counts on animals and in pasture were performed and the susceptibility of tick populations to the different treatment methods was evaluated at the beginning and end of the study using the Larval Packet Test, Larval Immersion Test, and Adult Immersion Test. Over the four years of the study strategic control was more advantageous than the selective control as the group experienced lower tick burden on animals and in pasture, absence of skin lesions and myiases, lower operating costs, treatments concentrated in fewer months of the year and lower resistance pressure.

Successful long-term control of poultry red mite (Dermanyssus gallinae) infestations in floor-kept laying hens via integrated pest management-a case report.

This case report describes the successful control of poultry red mite [PRM] (Dermanyssus gallinae) infestations in an experimental laying hen house via a combined use of cleaning and disinfection measure, the preventive application of a synthetic silica-based acaricide and frequent mite monitoring. The high number of PRM in the laying hen house was reduced by 99.8% by treatment with fluralaner (Exzolt®, MSD Animal Health Unterschleißheim, Germany; 0.5 mg/kg body weight via drinking water twice, 7 days apart). After the laying hens were removed, the hen house was dry-cleaned, wet-cleaned and disinfected. After drying, synthetic amorphous silica (Fossil Shield® instant white, Bein GmbH, Eiterfeld, Germany) was applied as a preventive measure before the hen house was restocked with pullets for two housing periods of 58 and 52 weeks. Over these periods (i.e. more than 2 years), no PRM was detected during mite monitoring at two-week intervals via tube traps and visual monitoring. This result therefore suggests that the combined use of appropriate chemical and physical prevention measures within an integrated pest management regime can be successfully used for the long-term control of PRM. This could reduce the use of acaricidal drugs, thereby helping maintain their efficacy.

Acaricidal efficacy evaluation of amitraz and diazinon against Amblyomma variegatum tick species in Waghimra zone, northern Ethiopia.

Ticks pose a substantial economic burden associated with production loss and treatment costs globally. Ethiopia has tremendous livestock resources, but its productivity is hindered by various animal health challenges in which ticks are the top priority, with a limited response to acaricidal treatments. Hence, we designed an acaricidal efficacy trial for the top commercially available Chemicals (amitraz and diazinon) to examine their efficacy against the widely distributed tick species (Amblyoma variegatum). Ticks were collected from animals admitted to veterinary clinics with no history of treatment with acaricides. Adult Immersion Technique (AIT) was employed to detect acaricidal resistance, and the mean percent control and antiparasitic efficacy were used to estimate tick susceptibility with a completely randomized laboratory-based trial (CRT). The mean weights of eggs laid by ticks subjected to amitraz and diazinon indicated that amitraz had a better egg-laying-inhibition effect than diazinon. The mean control percentages of amitraz and diazinon were 92.8 ± 5.6% and 69.7 ± 3.1%, respectively, with a highly significant difference (P-value = 0.00). The antiparasitic efficacy of the two drugs was 57.5 ± 0.96 and 37.5% ± 0.96 for amitraz and diazinon, respectively, which revealed that amitraz was statistically better than diazinon in killing adult ticks (P-value =0.026). In general, ticks treated with diazinon showed evidence of resistance development, and amitraz is relatively the most effective acaricide; we recommend its use in the study area and other locations with similar settings.

Prevalence of cattle ixodid ticks and acaricides efficacy evaluation in Amibara district of Afar Region, Ethiopia.

A cross sectional and randomized controlled trial study was conducted starting from July 2021 to July 2022 to determine the prevalence of ixodid ticks, and evaluate the efficacy of commonly used acaricides (amitraz 12.5% and diazinon 60%) in vitro and in vivo on cattle ticks in Amibara district. A total of 372 cattle were visited randomly from six kebeles of the district which were selected based on their livestock population. A total of 4330 adult ticks were collected and identified to the species level with stereomicroscope. For the invitro acaricide efficacy test, 90 engorged female ticks were collected from infested herds and grouped into three, each group having ten engorged ticks; two groups for the two test acaricides and the third groups were control to evaluate these acaricides in the laboratory. All the groups were replicated three times and incubated for seven days with similar temperature and humidity. Thirty-six infested cattle were selected and again grouped into three randomly, 12 each for the invivo test. The first groups of animals were sprayed with amitraz, the second with diazinon and the third groups were left untreated. Ticks were counted and recorded before, day 3, day 7, day 14 and day 21 of spraying. A total of 360 (96.7%) of the visited cattle were infested with ticks. Amblyomma. Rhipicephallus, Hyalomma and Bophillus were the genera of ticks identified with a prevalence of 44.9%, 41.4%, 7.5% and 6.2% respectively. A total of 15 species of ixodid ticks were identified from which Rhipicephallus pulchellus (39.86%) was dominant followed by Amblyomma lepidum (26.65%) and Amblyomma gemma (14.36%). Diazinon 60% EC and amitraz 12.5% were significantly inhibited the egg laying ability of engorged ticks' in vitro with percent inhibition of 100% and 99.1% respectively. On live animal, both acaricides showed statistically significant difference from the control group (p- value <0.05) with maximum 97.37% (amitraz) and 93.33% (diazinon) at day 7 and minimum 73.3% (amitraz) and 73.7% (diazinon) efficacy. However, there was no statistically significant difference on egg laying inhibition and tick count reduction between the two acaricides (p-value >0.05). Therefore, awareness should be created about the high prevalence as well as the application, dosage and dilution of the acaricides to pastoralists, community animal health workers and para veterinarians in the study area. Cattle owners, veterinarians and concerned government officials should address infested herds with manufacturer recommended dosage of these acaricides to control the tick infestation.

Poultry red mite eradication potential of ivermectin and allicin combination treatment.

BACKGROUND: Existing treatments against poultry red mite (PRM; Dermanyssus gallinae) infestation have reduced efficacy or exhibit hazardous effects on chickens. Considering the economic importance of chickens, development of a safe and effective method for exterminating PRMs is necessary. Ivermectin and allicin are effective against some ectoparasites; however, their acaricidal efficacies against PRMs remain unknown. OBJECTIVE: To evaluate individual and combined efficacies of ivermectin and allicin in exterminating PRMs. METHODS: Different concentrations (0.10-1.0 mg/mL) of ivermectin (1 mL) were applied via dropping method in different insect culture dishes (ICDs), prior to transferring PRMs. For the spraying method, PRMs were transferred to ICDs, before spraying ivermectin (1 mg/mL) solution (1 mL). Further, the acaricidal effect of allicin on PRMs was evaluated by applying different concentrations (0.25-1.0 mg/mL) of allicin (1 mL). The combined acaricidal effects of ivermectin and allicin were analysed using four concentration combinations. PRM death rates were determined after 2 h, 24 h, 2 days, 5 days and 7 days of drug application. RESULTS: Ivermectin application (1 mg/mL) exterminated 64% and 100% of PRMs on 1 and 5 days, respectively, and prevented their revival. Further, 0.5 mg/mL ivermectin and 1 mg/mL allicin individually exterminated 98% and 44% of PRMs, respectively, within 7 days of treatment. In combination, 0.5 mg/mL ivermectin and 0.5 mg/mL allicin exterminated 100% of PRMs within 5 d of treatment. The most effective combination was 0.25 mg/mL ivermectin + 1.00 mg/mL allicin. CONCLUSIONS: The efficacy of ivermectin-allicin combination in exterminating PRMs was demonstrated. This novel approach could be optimised for industrial applications.

Pharmacokinetic and pharmacodynamic considerations for treating sarcoptic mange with cross-relevance to Australian wildlife.

Sarcoptes scabiei is the microscopic burrowing mite responsible for sarcoptic mange, which is reported in approximately 150 mammalian species. In Australia, sarcoptic mange affects a number of native and introduced wildlife species, is particularly severe in bare-nosed wombats (Vombatus ursinus) and an emerging issue in koala and quenda. There are a variety of acaricides available for the treatment of sarcoptic mange which are generally effective in eliminating mites from humans and animals in captivity. In wild populations, effective treatment is challenging, and concerns exist regarding safety, efficacy and the potential emergence of acaricide resistance. There are risks where acaricides are used intensively or inadequately, which could adversely affect treatment success rates as well as animal welfare. While reviews on epidemiology, treatment strategies, and pathogenesis of sarcoptic mange in wildlife are available, there is currently no review evaluating the use of specific acaricides in the context of their pharmacokinetic and pharmacodynamic properties, and subsequent likelihood of emerging drug resistance, particularly for Australian wildlife. This review critically evaluates acaricides that have been utilised to treat sarcoptic mange in wildlife, including dosage forms and routes, pharmacokinetics, mode of action and efficacy. We also highlight the reports of resistance of S. scabiei to acaricides, including clinical and in vitro observations.

Efficacy of fluralaner chewable tablets (Bravecto®) against Asian longhorned tick (Haemaphysalis longicornis) infestations of dogs.

BACKGROUND: The parthenogenic reproductive ability of Haemaphysalis longicornis, facilitating quick life cycle completion and rapid geographic spread and its pathogen vector potential make infestations a risk to human and canine health. Two 90-day studies were initiated to evaluate the efficacy of a single fluralaner administration for the treatment and prevention of H. longicornis infestations on dogs. METHODS: Dogs were randomly assigned (10 dogs/group) to either an untreated control group or a group treated once (Day 0) with 13.64% w/w fluralaner chewable tablets (Bravecto®) at the minimum label dose rate of 25 mg/kg. Each dog was infested with approximately 50 H. longicornis ticks on Days -9 or -6 and on Days -2, 28, 58 and 88. A different US tick isolate was used in each study. Tick counts were completed on Days -7 or -4, 2, 30, 60 and 90. The primary efficacy criterion was a 90% reduction in arithmetic mean tick counts between the treated and control groups. For between-group comparisons at any assessment, at least six control dogs were required to retain at least 25% of the infestation dose (13 live ticks). RESULTS: Pre-study infestations demonstrated susceptibility of all study dogs to challenge with H. longicornis. At each subsequent assessment in both studies, at least seven untreated control dogs retained ≥ 25% of the challenge, demonstrating adequate infestations for each efficacy calculation. On Days 2, 30, 60 and 90 the mean live tick infestation rate (number of ticks recovered from each dog/infesting challenge of each dog) of untreated control dogs ranged from 27.8 to 60.8%. No live ticks, free or attached, were found on any fluralaner-treated dog in either study. Between-group differences were statistically significant (P ≤ 0.0002) at each assessment. CONCLUSION: At the minimum recommended label dose rate of 25 mg/kg, fluralaner chewable tablets were 100% effective in eliminating H. longicornis ticks from dogs infested at the time of treatment. Complete efficacy against both US isolates of this tick was maintained through 90 days following a single treatment. Therefore, fluralaner is a treatment of choice for protecting dogs against this invasive tick species.