RESUMEN
Trixacarus caviae is a sarcoptic mange mite infesting guinea pigs. Infestation in immunosuppressed animals produces severe dermatological problems, including alopecia, intense pruritus, hyperkeratosis and non-dermatological issues (e.g., seizures). Treatment options are limited and include topical application of macrocyclic lactones or amitraz or injectable administration of ivermectin or doramectin. Considering the severity of the disease and the challenging treatment, the present paper aimed to determine the efficacy of oral afoxolaner in a severe case of infestation with T. caviae in a pet guinea pig. One female guinea pig was referred to the New Companion Animal Clinic due to severe dermatological problems. A clinical evaluation was done, and skin scrapings were collected and examined under the microscope. Small mites were detected and morphologically identified as T. caviae. The animal was treated with a single oral dose of 2.50 mg/kg afoxolaner, and the lesions, presence/absence of mites and intensity of pruritus were evaluated periodically until 2 months post-treatment. A week after the medication, the lesions were milder, but pruritus was still present and was attributed to the healing process. Further examinations showed significant improvement with the complete remission of clinical signs and no mites at the microscopic examination after 4 weeks. Afoxolaner was safe and effective in this guinea pig for the treatment of T. caviae mange with no repetition needed.
Asunto(s)
Naftalenos , Animales , Cobayas , Femenino , Naftalenos/administración & dosificación , Naftalenos/uso terapéutico , Infestaciones por Ácaros/veterinaria , Infestaciones por Ácaros/tratamiento farmacológico , Infestaciones por Ácaros/parasitología , Acaricidas/uso terapéutico , Acaricidas/administración & dosificación , Mascotas , Pirimidinas/administración & dosificación , Pirimidinas/uso terapéutico , Enfermedades de los Roedores/tratamiento farmacológico , Enfermedades de los Roedores/parasitología , IsoxazolesRESUMEN
BACKGROUND: Canine acaricides with rapid onset and sustained activity can reduce pathogen transmission risk and enhance pet owner experience. This randomized, complete block design, investigator-masked study compared the speed of kill of Amblyomma americanum provided by three monthly-use isoxazoline-containing products. METHODS: Eight randomized beagles per group were treated (day 0), per label, with sarolaner (combined with moxidectin and pyrantel, Simparica Trio™), afoxolaner (NexGard™), or lotilaner (Credelio™), or remained untreated. Infestations with 50 adult A. americanum were conducted on days - 7, - 2, 21, and 28, and tick counts were performed on day - 5 (for blocking), and at 4, 8, 12, 24, 48, and 72 h following treatment and subsequent infestations. Efficacy calculations were based on geometric mean live tick counts. A linear mixed model was used for between-group comparisons. RESULTS: On day 0, only lotilaner significantly reduced an A. americanum infestation by 12 h (43.3%; P = 0.002). Efficacy of lotilaner and afoxolaner at 24 h post-treatment was 95.3% and 97.6%, respectively, both significantly different from sarolaner (74%) (P = 0.002, P < 0.001, respectively). On day 21, at 12 h postinfestation, lotilaner efficacy (59.6%) was significantly different from sarolaner (0.0%) (P < 0.001) and afoxolaner (6.3%) (P < 0.001). At 24 h, lotilaner efficacy (97.4%) was significantly different (P < 0.001) from sarolaner and afoxolaner (13.6% and 14.9%, respectively). On day 28, at 12 h postinfestation, lotilaner efficacy (47.8%) was significantly different from sarolaner (17.1%) (P = 0.020) and afoxolaner (9.0%) (P = 0.006). At 24 h, lotilaner efficacy (92.3%) was significantly different from sarolaner 4.9% (P < 0.001) and afoxolaner (0.0%) (P < 0.001). Speed of kill for sarolaner and afoxolaner, but not lotilaner, significantly declined over the study period. Following reinfestation on day 28, neither sarolaner nor afoxolaner reached 90% efficacy by 48 h. By 72 h, sarolaner efficacy was 97.4% and afoxolaner efficacy was 86.3%. Only lotilaner achieved ≥ 90% efficacy by 24 h post-treatment and 24 h postinfestation on days 21 and 28. Time to ≥ 90% efficacy following new infestations consistently occurred 24-48 h earlier for lotilaner compared with sarolaner or afoxolaner. CONCLUSIONS: Credelio (lotilaner) has a more rapid onset of acaricidal activity against A. americanum than Simparica Trio (sarolaner-moxidectin-pyrantel) and NexGard (afoxolaner). Only lotilaner's speed of tick kill is sustained throughout the dosing period.
Asunto(s)
Acaricidas , Amblyomma , Azetidinas , Enfermedades de los Perros , Isoxazoles , Infestaciones por Garrapatas , Animales , Perros , Infestaciones por Garrapatas/veterinaria , Infestaciones por Garrapatas/tratamiento farmacológico , Infestaciones por Garrapatas/prevención & control , Acaricidas/administración & dosificación , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/parasitología , Isoxazoles/administración & dosificación , Isoxazoles/uso terapéutico , Amblyomma/efectos de los fármacos , Azetidinas/administración & dosificación , Azetidinas/uso terapéutico , Femenino , Compuestos de Espiro/administración & dosificación , Compuestos de Espiro/uso terapéutico , Masculino , Factores de Tiempo , Naftalenos/administración & dosificación , Naftalenos/uso terapéutico , Resultado del Tratamiento , Oxazoles , TiofenosRESUMEN
NexGard®PLUS (moxidectin, afoxolaner, and pyrantel pamoate), is an oral combination product for dogs indicated for the prevention of heartworm disease, the treatment and prevention of flea and tick infestations, and the treatment of gastro-intestinal nematode infections. The safety of this product in dogs was evaluated in three studies. Study #1 was a margin-of-safety study conducted in puppies, dosed six times at 28-day intervals at 1X, 3X, or 5X multiples of the maximum exposure dose (equivalent to 24 µg/kg moxidectin, 5 mg/kg afoxolaner, and 10 mg/kg pyrantel). In Study #2, the product was administered to ABCB1-deficient collie dogs at a 1X dose twice at a 28-day interval, and at a 3X or 5X dose once. Study #3 evaluated the safety of the product at 1X and 3X doses administered three times at 4-week intervals, to dogs harboring adult Dirofilaria immitis. In the three studies, the safety was evaluated on the basis of multiple clinical observations and physical examinations, including a complete assessment of toxicity to macrocyclic lactones, and on comprehensive clinical and anatomical pathology evaluations in Study #1. No clinically significant combination product-related effects were observed in any of the three studies. No signs of macrocyclic lactone toxicity were observed in the ABCB1-deficient collie dogs. Some mild and self-resolving instances of emesis or diarrhea were occasionally observed in the 3X and 5X dosed dogs. NexGard® PLUS was demonstrated to be safe following multiple administrations in puppies, in ABCB1-deficient collie dogs, and in microfilaremic dogs infected with adult D. immitis.
Asunto(s)
Enfermedades de los Perros , Combinación de Medicamentos , Macrólidos , Pamoato de Pirantel , Animales , Perros , Macrólidos/administración & dosificación , Macrólidos/uso terapéutico , Macrólidos/efectos adversos , Masculino , Femenino , Enfermedades de los Perros/tratamiento farmacológico , Pamoato de Pirantel/administración & dosificación , Pamoato de Pirantel/uso terapéutico , Pamoato de Pirantel/efectos adversos , Isoxazoles/administración & dosificación , Isoxazoles/uso terapéutico , Administración Oral , Dirofilariasis/tratamiento farmacológico , Dirofilaria immitis/efectos de los fármacos , Naftalenos/administración & dosificaciónRESUMEN
A German Shepherd dog was presented to a referral practice for screwworm myiasis affecting the ear. The successful management involved killing the larvae with afoxolaner plus milbemycin oxime and using video otoscopy to completely remove dead larvae. To the best of our knowledge, this is the first case report of auricular myiasis by Chrysomya bezziana in a dog in Singapore and the first report of video otoscopic management of myiasis.
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Dípteros , Enfermedades de los Perros , Miasis , Infección por Gusano Barrenador , Animales , Perros , Infección por Gusano Barrenador/diagnóstico , Infección por Gusano Barrenador/terapia , Infección por Gusano Barrenador/veterinaria , Singapur , Miasis/diagnóstico , Miasis/veterinaria , Larva , Enfermedades de los Perros/diagnósticoRESUMEN
Otodectes cynotis, commonly known as "the ear mite," is a highly contagious ectoparasite and a significant cause of otitis externa in canines. The objective of the current study was to determine the efficacy of the isoxazoline afoxolaner (Nexgard®), and the combination of afoxolaner with milbemycin oxime (Nexgard Spectra®), in dogs naturally infested with O. cynotis. In total, 32 infested client-owned dogs from two different sites in Greece were included. The animals were randomly divided into four equal groups based on their infestation score. Group 1 served as the negative control, group 2 received one oral administration of Nexgard (Day 0), group 3 received two monthly oral administrations of Nexgard (Days 0, 30), and group 4 received two monthly oral administrations of Nexgard Spectra (Days 0, 30), according to label instructions. Otoscopic examinations for mites and observations on debris/cerumen in the ears were carried out on Days 0, 15, 30, and 45. A quantitative assessment of ear mites by ear duct flushing and live mite counts was performed on Day 45. The results demonstrated that a single oral dose of afoxolaner and two monthly doses of afoxolaner or afoxolaner with milbemycin oxime resulted in a 99.9% reduction in live mite counts compared to the untreated control group by Day 45. Additionally, treated dogs showed improved clinical symptoms, such as ear cerumen/debris decrease, while untreated dogs experienced worsening symptoms over the study duration. No adverse events were reported. Overall, these results support the use of afoxolaner-based products to treat O. cynotis infestation in dogs.
Asunto(s)
Enfermedades de los Perros , Macrólidos , Infestaciones por Ácaros , Animales , Perros , Administración Oral , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/parasitología , Isoxazoles , Macrólidos/administración & dosificación , Naftalenos , Psoroptidae , Antihelmínticos/administración & dosificación , Infestaciones por Ácaros/tratamiento farmacológico , Infestaciones por Ácaros/parasitología , Resultado del TratamientoRESUMEN
BACKGROUND: The sand flea Tunga penetrans is one of the agents of tungiasis, an important parasitic skin disease affecting humans and several mammalian species. Tungiasis is mainly observed in disadvantaged rural and peripheral urban communities in Latin America and sub-Saharan Africa. The dog is a major reservoir of Tunga fleas. Hematophagous adult female Tunga spp. embed and grow in their host's epidermis and cause cutaneous inflammatory disorders. NexGard Spectra® is an orally administered endectocide for dogs, a co-formulation of the isoxazoline afoxolaner and the macrocyclic lactone milbemycin oxime. The objective of this study was to assess the efficacy of this product against canine tungiasis. METHODS: A blinded, negative-controlled field trial was conducted in a Brazilian community known to be highly endemic for tungiasis. Sixty-six dogs naturally infected with live T. penetrans were randomly allocated to a treated group (44 dogs) and an untreated control group (22 dogs). In a first phase, dogs from the treated group were treated on days 0, 30, and 60. Efficacy was evaluated on the basis of the macroscopic parasitic skin lesions (Fortaleza classification) on days 7, 14, 21, 30, 45, 60, 75, and 90. In a second phase, to evaluate natural reinfections, all dogs were treated on day 90 and evaluated every 2 weeks thereafter until at least 30% of dogs were infected with live sand fleas. RESULTS: During the first phase, efficacy (reduction in live sand fleas) of 92.4% was demonstrated on day 7. From day 14 until day 90, the efficacy of NexGard Spectra® was 100%. In the second phase, all dogs were free of live T. penetrans from 15 until 45 days after the day 90 treatment; 60 days post-treatment, 11% of dogs were reinfected, and 75 days post-treatment, 40% of dogs were reinfected. CONCLUSIONS: NexGard Spectra® was demonstrated to be highly effective against canine tungiasis. In addition to an obvious beneficial effect on the health and welfare of the treated dog, the use of this product may have a one-health benefit on human cases by controlling the main reservoir of sand fleas.
Asunto(s)
Enfermedades de los Perros , Infestaciones por Pulgas , Tungiasis , Animales , Perros , Humanos , Femenino , Tungiasis/tratamiento farmacológico , Tungiasis/veterinaria , Tunga , Infestaciones por Pulgas/tratamiento farmacológico , Infestaciones por Pulgas/veterinaria , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/parasitología , MamíferosRESUMEN
The efficacy of the combination of milbemycin oxime and afoxolaner was evaluated in desert tortoises infested with fly larvae. Oral administration of the combination of milbemycin oxime and afoxolaner eliminated the infestation without generating any evident adverse effects on the tortoises.
L'efficacité de la combinaison de milbémycine oxime et d'afoxolaner a été évaluée chez des tortues du désert infestées par des larves de mouches. L'administration orale de la combinaison de milbémycine oxime et d'afoxolaner traite l'infestation sans générer d'effets indésirables évidents sur les tortues.
A eficácia da associação de milbemicina oxima e afoxolaner foi avaliada em tartarugas do deserto infestadas por larvas de moscas. A administração oral da combinação de afoxolaner e milbemicina oxima eliminou a infestação sem gerar nenhum efeito adverso evidente às tartarugas.
Se evaluó la eficacia de la combinación de milbemicina oxima y afoxolaner en tortugas del desierto infestadas con larvas de mosca. La administración oral de la combinación de milbemicina oxima y afoxolaner eliminó la infestación sin generar efectos adversos evidentes en las tortugas.
Asunto(s)
Enfermedades de los Perros , Moscas Domésticas , Miasis , Tortugas , Animales , Perros , Macrólidos/uso terapéutico , Miasis/veterinaria , Administración Oral , Enfermedades de los Perros/tratamiento farmacológicoRESUMEN
Dirofilaria immitis, the mosquito-borne agent of dirofilariosis, a chronic and sometimes fatal cardiopulmonary canine disease, is endemic in most warm and temperate regions in the world. The efficacy of an oral endectoparasiticide product (test product or TP) combining moxidectin, afoxolaner, and pyrantel pamoate was evaluated for the prevention of heartworm disease in dogs, in two laboratory and one field studies. In each laboratory study, 20 D. immitis-naïve beagle dogs were experimentally infected with D. immitis. Ten control dogs were sham-treated, and ten dogs were administered the TP targeting the minimum effective dose, six times monthly and starting 30 days post infection. At necropsy seven months after inoculations, no heartworms were found in any of the TP treated dog, whereas 19 to 42 live heartworms were found in the control dogs. In each study, treatment efficacy was 100% and the difference between treated and untreated groups was highly significant (p < 0.0001). A field study was conducted through the full transmission season in several heartworm-endemic regions of the United States. One hundred and twenty client-owned dogs that were negative for D. immitis at enrollment were administered twelve monthly oral doses of the TP at label dose. Blood tests for D. immitis antigen and modified Knott's tests for microfilariae remained negative through the full duration of the study, demonstrating that all dogs were protected from heartworm infection during the full transmission season. These studies demonstrated that TP administered monthly for at least six doses is effective at preventing dirofilariosis.
Asunto(s)
Dirofilaria immitis , Dirofilariasis , Enfermedades de los Perros , Cardiopatías , Perros , Animales , Estados Unidos , Dirofilariasis/tratamiento farmacológico , Dirofilariasis/prevención & control , Pamoato de Pirantel/farmacología , Pamoato de Pirantel/uso terapéutico , Macrólidos/uso terapéutico , Cardiopatías/veterinaria , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/prevención & controlRESUMEN
BACKGROUND: Ophionyssus natricis is the main species of mite that infests captive reptiles. High infestations may result in the host experiencing general discomfort and deleterious effects, even death. Moreover, O. natricis is an important vector of reptile vector-borne diseases and is considered to be the putative vector of the Reptarenavirus, the causal agent of the inclusion body disease. Despite the cosmopolitan distribution of O. natricis in captive reptiles, treatment options are limited. The aim of the present study was to assess the efficacy of afoxolaner (NexGard®; Boehringer Ingelheim, Ingelheim, Germany) in heavily infested, privately owned snakes, evaluate the prevalence of mites and drug availability in the plasma of treated snakes (pharmacokinetics) and perform a clinical examination of animals. METHODS: The study was conducted in two snake breeding facilities, where many snakes were infested with mites. Each animal was clinically examined and weighed, and mite infestations were assessed on the animals and in their enclosures (environment). Animals were treated with a dose of 2.5 mg afoxolaner per kilogram body weight (2.5 mg/kg) administered orally. All animals were examined pre-treatment (T0) and at various time points post-treatment (T1, 6 h; T2, 24 h; T3, 14 days; T4, 28 days). The collected mites were morphologically identified at the species level and the species identity also confirmed molecularly. RESULTS: Overall, 81 snakes from the two participating facilities (i.e. 70 from site 1 and 11 from site 2) were screened, and 31 (38.3%) snakes were found to have at least one mite. All mites were identified morphologically and molecularly as O. natricis. Lampropeltis was the genus of snakes with highest number of infested individuals. Mites were found to be alive on snakes at T1, but at T2 only dead mites were observed, and at T3 and T4 mites were no longer present on the animals or in their environment. No side effects were observed in the treated snakes. CONCLUSIONS: A single oral administration of afoxolaner at 2.5 mg/kg was a safe treatment for snakes and 100% effective for the eradication of natural O. natricis infestation without the need to treat the environment of the snake.
Asunto(s)
Enfermedades de los Perros , Infestaciones por Ácaros , Ácaros , Animales , Perros , Infestaciones por Ácaros/tratamiento farmacológico , Infestaciones por Ácaros/prevención & control , Infestaciones por Ácaros/veterinaria , Serpientes , Isoxazoles , Enfermedades de los Perros/tratamiento farmacológicoRESUMEN
BACKGROUND: Afoxolaner is a novel representative of the isoxazolines, a class of ectoparasiticides which has been commercialized for the control of tick and flea infestations in dogs. In this study, the biological efficacy of afoxolaner against the two-spotted spider mite Tetranychus urticae was evaluated. Furthermore, as isoxazolines are known inhibitors of γ-aminobutyric acid-gated chloride channels (GABACls), the molecular mode of action of afoxolaner on T. urticae GABACls (TuRdls) was studied using functional expression in Xenopus oocytes followed by two-electrode voltage-clamp (TEVC) electrophysiology, and results were compared with inhibition by fluralaner, fipronil and endosulfan. To examine the influence of known GABACl resistance mutations, H301A, I305T and A350T substitutions in TuRdl1 and a S301A substitution in TuRdl2 were introduced. RESULTS: Bioasassays revealed excellent efficacy of afoxolaner against all developmental stages and no cross-resistance was found in a panel of strains resistant to most currently used acaricides. Laboratory selection over a period of 3 years did not result in resistance. TEVC revealed clear antagonistic activity of afoxolaner and fluralaner for all homomeric TuRdl1/2/3 channels. The introduction of single, double or triple mutations to TuRdl1 and TuRdl2 did not lower channel sensitivity. By contrast, both endosulfan and fipronil had minimal antagonistic activities against TuRdl1/2/3, and channels carrying single mutations, whereas the sensitivity of double and triple TuRdl1 mutants was significantly increased. CONCLUSIONS: Our results demonstrate that afoxolaner is a potent antagonist of GABACls of T. urticae and has a powerful mode of action to control spider mites. © 2022 Society of Chemical Industry.
Asunto(s)
Animales , PerrosRESUMEN
BACKGROUND: Trichodectes canis is a small chewing louse found globally that primarily infests dogs. Limited information is available on the efficacy of isoxazolines against infestation with the chewing louse. In the present study, we evaluated the efficacy of afoxolaner, an isoxazoline class compound, in naturally infested domestic dogs. METHODS: The field study was carried out in Romania. Between September 2021 and December 2021, 43 dogs with confirmed T. canis infestation were included in the study. On the day of the inclusion (day 0), each animal was clinically examined and randomly treated with a control product labeled for use against lice [fipronil-(S)-methoprene combination (Frontline Combo®; Boehringer Ingelheim)] or with the investigational product [chewable tablets containing afoxolaner (NexGard®; isoxazoline)]. Each animal was evaluated for the presence of lice at 15 and 30 days post-inclusion. RESULTS: Of the 48 dogs initially included in the study, 43 completed the treatment period [18 in the control group (CG) and 25 in the investigational group (IG)]. At day 14, no living T. canis lice were detected on the dogs in either group. At day 14, dead lice were detected in four dogs in the IG, while eggs were present in two dogs in the IG and in one dog in the CG. At day 30, no lice were detected in either group, while eggs were still present in one dog in the CG. CONCLUSION: These results suggest that afoxolaner is a feasible treatment option against chewing lice in dogs, providing 100% curative efficacy.
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Canidae , Enfermedades de los Perros , Ischnocera , Animales , Enfermedades de los Perros/tratamiento farmacológico , Perros , Isoxazoles/uso terapéutico , NaftalenosRESUMEN
Afoxolaner, an insecticide and acaricide compound of the isoxazoline class, is available for dogs as an oral ectoparasiticide medicine (NexGard®) and as an oral endectoparasiticide medicine in combination with milbemycin oxime (MO), a macrocyclic lactone (NexGard® Spectra). The safety of these two compounds, alone or in combination, was investigated in homozygous MDR1-deficient collie dogs, in two studies. Overall, 30 adult collie dogs were treated once orally, 9 with a placebo, 9 with afoxolaner, 6 with MO, and 6 with a combination of afoxolaner and MO. For afoxolaner, the mean investigated dosage corresponded to 3.8 and 4.7 multiples of the maximum recommended therapeutic doses (RTD) in NexGard® and NexGard® Spectra, respectively. For MO, the mean investigated dosage corresponded to 4.7 multiples of the maximum RTD in NexGard® Spectra. Dogs were closely monitored for adverse reactions on the day of treatment and for the following two days. No significant adverse reaction was observed in any dog from the afoxolaner or the afoxolaner + MO groups; in the MO-only treated group, mild and transient neurological signs were observed during the 4-8 h post-treatment window. These studies demonstrated a high level of safety of oral afoxolaner, alone or in combination with milbemycin oxime, in homozygous MDR1-deficient dogs.
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Enfermedades de los Perros , Administración Oral , Animales , Enfermedades de los Perros/inducido químicamente , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/genética , Perros , Isoxazoles , Macrólidos , NaftalenosRESUMEN
A number of parasiticides are commercially available as companion animal treatments to protect against parasite infestation and are sold in large volumes. These treatments are not intended to enter the wider environment but may be washed off or excreted by treated animals and have ecotoxic impacts. A systematic literature review was conducted to identify the existing evidence for the toxicity of the six most used parasiticides in the UK: imidacloprid, fipronil, fluralaner, afoxolaner, selamectin, and flumethrin. A total of 17,207 published articles were screened, with 690 included in the final evidence synthesis. All parasiticides displayed higher toxicity towards invertebrates than vertebrates, enabling their use as companion animal treatments. Extensive evidence exists of ecotoxicity for imidacloprid and fipronil, but this focuses on exposure via agricultural use and is not representative of environmental exposure that results from use in companion animal treatments, especially in urban greenspace. Little to no evidence exists for the ecotoxicity of the remaining parasiticides. Despite heavy usage, there is currently insufficient evidence to understand the environmental risk posed by these veterinary treatments and further studies are urgently needed to quantify the levels and characterise the routes of environmental exposure, as well as identifying any resulting environmental harm.
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Antiparasitarios , Insecticidas , Animales , Insecticidas/toxicidad , Neonicotinoides , Nitrocompuestos/toxicidad , Mascotas , Reino UnidoRESUMEN
The isoxazolines are a novel class of ectoparasiticides with potent inhibitory activity on glutamate- and gamma-aminobutyric acid-gated chloride channel located in nervous system of invertebrates. In recent years, studies have been performed to evaluate the efficacy and safety of isoxazolines against various types of ectoparasites, including fleas, ticks, and mites. As more single and combined isoxazoline products have been approved by the United States Food and Drug Administration and European Medicines Agency, a more comprehensive understanding of isoxazolines becomes essential for veterinary clinical practitioners. This article provides a complete review of isoxazolines with respect to pharmacodynamics, pharmacokinetics, ectoparasiticidal efficacy, and safety, which will provide veterinarians information to allow them to make the best choice of ectoparasiticide for their clients' specific needs.
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Infestaciones por Pulgas , Insecticidas , Siphonaptera , Garrapatas , Animales , Canales de Cloruro , Infestaciones por Pulgas/veterinaria , Isoxazoles/uso terapéuticoRESUMEN
Otodectes cynotis is a commonly occurring surface mite that can be easily transmitted between suitable hosts, including dogs, causing otocariosis. The activity of the systemic insecticide afoxolaner against O. cynotis has been tested once under experimental conditions, showing a high efficacy. The present study aimed to i) assess the efficacy of two consecutive monthly oral administrations of afoxolaner (NexGard®) against O. cynotis in naturally infested dogs under field conditions and ii) evaluate its impact in reducing bacteria or fungal secondary infections. Dogs, positive for O. cynotis (n = 20), were included in the study and allocated in two groups of ten animals each (G1, control group, and G2, treated group). The first group of ear mite-infested dogs was treated with a placebo, while afoxolaner was administered orally to the second group of dogs at Day 0 (D0) and Day 30 (D30), following label instructions. Otoscopic assessments, deep-swab method and swab samples were performed on all dogs (Days 0, 30, 42) to evaluate the presence or absence of live mites and their number throughout the study, as well as to conduct bacterial and fungal assessments. No adverse events likely related were recorded throughout the study. By Day 42 (D42), all dog's ears were flushed to recover ear mites. All treated dogs became negative, as well as two dogs of the control group. The treatment efficacy of afoxolaner was 100 % based on the arithmetic means of the live mite counts. The clinical scores did not change significantly in the control group, whereas they significantly improved in the treated one from D0 to D30 (p-value = 5.47 10-5). No live mites were present in the afoxolaner-treated group at D42 (p-value = 0.00073). In this field study, two oral administrations of afoxolaner at the recommended dose allowed a complete cure of the infestation. Bacterial and Malassezia pachydermatis infections were detected in both groups, although no significant trend was associated to the ear mite treatment.
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Enfermedades de los Perros , Infestaciones por Ácaros , Ácaros , Administración Oral , Animales , Enfermedades de los Perros/tratamiento farmacológico , Perros , Isoxazoles/uso terapéutico , Infestaciones por Ácaros/tratamiento farmacológico , Infestaciones por Ácaros/veterinaria , Naftalenos , Resultado del TratamientoRESUMEN
Afoxolaner is a new insecticidal and acaricidal active pharmaceutical ingredient (API) belonging to the isoxazoline family, widely prescribed for the control of fleas and ticks in dogs. A stability-indicating reversed-phase high performance liquid chromatography (RP-HPLC) method has been developed for the assay of afoxolaner and determination of its related compounds in bulk API lots of afoxolaner. The chromatographic separation of afoxolaner and its related compounds was achieved by gradient elution on a Zorbax-SB C18 column (50 mm × 4.6 mm i.d., 5 µm particle size) maintained at 40 °C. Mobile phase-A is composed of water and mobile phase-B is composed of acetonitrile/methanol (50/50, v/v). Analytes were monitored by UV detection at 225 nm with a flow rate of 2.0 mL/min. The stability-indicating capability of the method has been demonstrated by adequate separation of all the process related impurities and degradation products of afoxolaner generated by stress degradation of afoxolaner bulk drug substance under various stress conditions. This method was also successfully validated as per the current ICH guidelines for afoxolaner and Q6S07 (afoxolaner related substance) with respect to specificity, linearity (R2 > 0.999), detection limit (â¼0.21 µg/mL), quantitation limit (â¼0.70 µg/mL), accuracy, precision, and robustness. Due to its speed, high degree of selectivity, and accuracy, the proposed method is suitable and highly desirable in quality control laboratories for routine analysis of afoxolaner.
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Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Fase Inversa/métodos , Isoxazoles/análisis , Isoxazoles/química , Naftalenos/análisis , Naftalenos/química , Límite de Detección , Modelos Lineales , Reproducibilidad de los ResultadosRESUMEN
This study was conducted to assess the acaricidal efficacy of afoxolaner (NexGard®, Boehringer Ingelheim), and fipronil - permethrin (Frontline® Tri-Act, Boehringer Ingelheim) administered once to dogs experimentally infested with Hyalomma marginatum ticks. Twenty-four Beagle dogs were randomly allocated based on a pre-treatment H. marginatum infestation to an untreated control group, a NexGard® or a Frontline® Tri-Act treated groups. Treatments were administered once on Day 0 as per the products' labels. For the efficacy evaluation, dogs were experimentally infested with 30 adult H. marginatum ticks on Days -2, 7, 28 and 36. In-situ counts were performed at 48 h post-treatment on Day 2 and post-infestations on Days 9, 30 and 38. Ticks were removed and counted at 72 h post-treatment on Day 3 and after each tick infestation on Days 10, 31 and 39. The numbers of live ticks counted in the treated groups were significantly different than in the control group at all time-points (p ≤ 0.0006). The efficacy was at least 97% after 48 h, and at least 99% after 72 h for both treatments. In this study both afoxolaner and fipronil/permethrin formulations demonstrated a high efficacy against adult H. marginatum ticks in treated dogs for at least five weeks.
Asunto(s)
Enfermedades de los Perros , Garrapatas , Animales , Enfermedades de los Perros/tratamiento farmacológico , Perros , Isoxazoles , Naftalenos , Permetrina , PirazolesRESUMEN
BACKGROUND: Leishmania infantum and Dirofilaria immitis are among the most important canine vector-borne pathogens (CVBPs) of zoonotic concern in Europe. In endemic areas for both of these CVBPs, the use of systemic ectoparasiticides, such as afoxolaner (NexGard®; Boehringer Ingelheim Animal Health), may have the potential for controlling these infections. The aim of this study was to assess, for the first time, the insecticidal efficacy of NexGard® in decreasing the transmission of D. immitis and L. infantum to sheltered dogs living in a hyperendemic area, compared to the year before treatment, as well as its impact on the abundance of mosquito and sand fly populations. METHODS: All dogs (n = 179) enrolled in the study were divided into two groups based on their infection status at enrollment: a non-infected group (G1) and an infected group (G2; infected with D. immitis, L. infantum or both). The study was conducted from March 2020 to March 2021. In order to exclude all animals infected with L. infantum and D. immitis before March 2020 (sampling time: T0), dogs in G1 were sampled in June (T1; i.e. T0 + 90 days) and in October 2020 (T2; i.e. T0 + 210 days). From March to September 2020, all animals (G1 and G2) were weighed and treated monthly with NexGard®. Animals in G1 were tested for the last time in March 2021 (T3; i.e. T0 + 330 days) for assessing post-treatment incidence rate of infection and prevention efficacy. RESULTS: The post-treatment incidence of D. immitis was 3.7% (1/27; 95% confidence interval [CI]: 0.2-18.1) and that of L. infantum was 3.6% (3/83; 95% CI: 1.0-10.1). Considering the annual incidence in 2019 and 2020, the protective efficacy against D. immitis and L. infantum infections was 94.2 and 64%, respectively. Of the female mosquitoes collected (n = 146), only one pool out of 50 tested positive for D. immitis DNA, whereas out of 1252 female Sergentomya minuta specimens collected, only four tested positive for L. infantum (0.3%). CONCLUSIONS: Afoxolaner is efficacious in decreasing the rate of transmission of both D. immitis and L. infantum; however, comparison of the pre- and post-treatment period demonstrated that there was a significant difference only in the seasonal incidences of D. immitis infection. Preventive measures are recommended throughout the year in endemic areas to reduce the risk of pathogen transmission to animals and humans.
Asunto(s)
Dirofilaria immitis/efectos de los fármacos , Dirofilariasis/prevención & control , Enfermedades de los Perros/prevención & control , Isoxazoles/uso terapéutico , Leishmania infantum/efectos de los fármacos , Leishmaniasis Visceral/veterinaria , Naftalenos/uso terapéutico , Animales , Dirofilariasis/tratamiento farmacológico , Dirofilariasis/transmisión , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/transmisión , Perros , Enfermedades Endémicas/veterinaria , Femenino , Insectos Vectores/clasificación , Isoxazoles/farmacología , Isoxazoles/normas , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/prevención & control , Leishmaniasis Visceral/transmisión , Mosquitos Vectores/clasificación , Naftalenos/farmacología , Naftalenos/normas , Psychodidae/clasificación , Tiempo (Meteorología)RESUMEN
New World screwworm (NWS) myiasis is an infestation by Cochliomyia hominivorax larvae that consume the living tissue of warm-blooded animals, including humans. Domestic dogs are among the potential hosts of these flies that lay their eggs on the edges of wounds. NWS myiasis cases can be fatal if untreated. Treatment with parasiticides must be fast-acting, long-lasting and show 100% efficacy, since open wounds can be reinfested. Afoxolaner is a molecule from the isoxazoline family with proven ectoparasiticide action against fleas, ticks and mites in dogs. Fourteen healthy client-owned dogs, naturally infested by C. hominivorax larvae, were treated with afoxolaner (NexGard®) as per label recommendations, providing at least the minimum dosage of 2.5 mg/kg. Maggot infestations were classified as light (fewer than 10 larvae), mild (from 10 to 20 larvae) or severe (more than 20 larvae), according to the number of larvae found in the wound and/or collected from the ground after treatment. Twenty-four hours post-treatment, infested lesions were carefully inspected and collected larvae were counted and classified as live or dead. All maggots were identified as second and third instar larvae of C. hominivorax and were found dead within 24 h after treatment, demonstrating 100% larvicidal efficacy against C. hominivorax.
Asunto(s)
Dípteros , Enfermedades de los Perros , Miasis , Animales , Calliphoridae , Enfermedades de los Perros/tratamiento farmacológico , Perros , Isoxazoles , Miasis/tratamiento farmacológico , Miasis/veterinaria , NaftalenosRESUMEN
The objective of this experimental study was to assess the insecticidal efficacy of afoxolaner (NexGard®) against bedbugs (Cimex lectularius) on dogs. For each challenge, 20 bedbugs were placed in two chambers positioned in contact to the dog's skin for 15 min, after which live fed parasites were counted and incubated for survival evaluations. On Day 0, 7 dogs assigned to the treated group were administered afoxolaner orally at the registered dose. All 14 dogs were challenged on Days 1, 7, 14, 21 and 28, and the collected live fed C. lectularius incubated for 72 h (Day 1), and 72 h and 96 h (Days 7, 14, 21 and 28) for survival evaluation. The percent feeding in the control group ranged from 95% to 98.6% and the percent of live fed bedbugs at 96 h ranged from 99.3% to 100% in the control group, demonstrating the viability of the strain and their capacity to feed on dogs. Significantly fewer live fed bedbugs were counted in the treated group, compared to the control group, at all time-points. The reduction of live fed C. lectularius in the afoxolaner group was 41.4% at 72 h after the Day 1 challenge, and 77.2%, 82.7%, 85.0% and 63.5% at 96 h after the Days 7, 14, 21 and 28 challenges, respectively. It is hypothesized that monthly treatment of dogs with afoxolaner could help in preventing a bed bug population from installing in a household if bedbugs bite dogs in the presence of humans.
TITLE: Efficacité insecticide de l'afoxolaner administré par voie orale à des chiens contre les punaises de lit, Cimex lectularius. ABSTRACT: L'objectif de cette étude expérimentale était de déterminer l'efficacité insecticide de l'afoxolaner (NexGard®) contre les punaises de lit (Cimex lectularius) chez les chiens. Pour chaque exposition, 20 punaises de lit ont été mises dans deux chambres placées en contact avec la peau des chiens pendant 15 minutes. Après cela, les parasites vivants et gorgés ont été comptés et incubés pour évaluer leur survie. Le jour 0, 7 chiens affectés au groupe traité ont reçu de l'afoxolaner (NexGard) par voie orale à la dose commerciale. Les 14 chiens ont été exposés aux punaises aux jours 1, 7, 14, 21 et 28, et les C. lectularius vivants et gorgés, collectés, ont été incubés pendant 72 h (jour 1) et 72 et 96 h (jours 7, 14, 21 et 28) pour l'évaluation de la survie. Le pourcentage d'engorgement dans le groupe témoin variait de 95 % à 98,6 % et le pourcentage de ces punaises vivantes à 96 h variait de 99,3 à 100 %, démontrant la viabilité de la souche et la capacité à se nourrir des chiens. Le nombre de punaises vivantes était significativement plus faible dans le groupe traité, par rapport au groupe témoin, à chaque point de contrôle. La réduction de C. lectularius vivants dans le groupe afoxolaner était de 41,4 % à 72 h après l'exposition du jour 1, et respectivement de 77,2 %, 82,7 %, 85,0 %, et 63,5 % à 96 h après les expositions des jours 7, 14, 21, et 28. On peut donc faire l'hypothèse que le traitement mensuel des chiens avec de l'afoxolaner pourrait empêcher une population de punaises de lit de s'installer dans un foyer, si les punaises piquent les chiens en présence d'humains.