Efficacy of fluralaner spot-on solution for the treatment of Ctenocephalides felis and Otodectes cynotis mixed infestation in naturally infested cats

Efficacy and innocuity of lotilaner in the treatment of otodectic mange in ferrets

Otodectes cynotis is a contagious ear mite generally responsible of a parasitic otitis. This prospective study evaluates the efficacy, safety and impact on quality of life (QoL) of oral lotilaner for the treatment of Otodectes infestation in ferrets. Ferrets of weight greater than 500 g, with Otodectes mites confirmed on ear swabs examination and that did not receive an acaricidal treatment in the previous two weeks were included. Oral lotilaner (Credelio 12 mg, ELANCO FRANCE, Sèvres, France) was administered at inclusion day (D0) and 28 days later (D28). Parasitic counts and clinical examination were performed at D0, D28 and D56. A QoL and owner satisfaction questionnaire was given at D0 and D56. Statistical analysis was performed with Shapiro-Wilk test for normality and Wilcoxon test for mean comparison (significance: p<0.05). Eleven ferrets were included, two were asymptomatic. Mean weight was 1.2 kg (0.68-2.66). Mean lotilaner dose was 12.3 mg/kg (9-17.6). Mean eggs, adults or nymphs, larvae, and fragments counts were 30.4 (3-104), 11.2 (1-61), 5.4 (0-36), 3.5 (1-7) respectively at D0; 0, 0, 0.1 (0-1), 0.5 (0-3) respectively at D28; 0, 0, 0, 0.14 (0-1) respectively at D56. Differences were statistically significant from baseline in all cases (p<0.05). Pruritus was absent in all cases at D56. No adverse effects were reported. All owners were "completely satisfied" with the treatment. Mean impact of the disease on QoL was 4.5/18 (SD=4.15) at D0 and 0 at D56 (significant difference, p<0.05). Oral lotilaner appears as a safe, efficient, easy to use and satisfactory treatment of Otodectes cynotis infestation in ferrets.

Successful treatment of 3 naturally acquired cases of canine cheyletiellosis with fluralaner

Three dogs were diagnosed with naturally occurring cheyletiellosis based on clinical signs and visualization of parasites and ova. Treatment with fluralaner (orally) resulted in a rapid resolution of clinical signs with no evidence of mites or ova at 1 or 2 mo post-treatment. This is apparently the first published report of an isoxazoline being used to successfully treat cheyletiellosis in veterinary medicine. Therefore, fluralaner may be an effective option for treatment or prevention of canine cheyletiellosis, although research is needed to confirm its effectiveness for treatment of cheyletiellosis in dogs and other species. Key clinical message: This is apparently the first published report of an isoxazoline being used to successfully treat cheyletiellosis in companion animal practice. These parasites are both contagious and zoonotic and there are currently no approved products for treatment or prevention of cheyletiellosis.

Field efficacy and safety of Felpreva® (tigolaner, emodepside and praziquantel) spot-on for the treatment of natural ear mite infestations (Otodectes cynotis) and notoedric mange (Notoedres cati) in cats

The miticide efficacy of a single treatment with Felpreva® (tigolaner, emodepside and praziquantel) spot-on solution for cats was evaluated in two European field studies. One study was conducted in cats naturally infested with Otodectes cynotis. The other study was conducted in cats naturally infested with Notoedres cati. In both studies, the presence of viable mites was confirmed prior to treatment (Day -1/Day 0) and re-evaluated on Day 14 (O. cynotis study) and on Day 28 (both studies). Efficacy was calculated based on the number of viable mites found after treatment. In the O. cynotis study, the primary criterion was the percentage of mite-free cats after treatment with Felpreva® compared to a sarolaner/selamectin combination (Stronghold® Plus, Zoetis) as a positive control. In the N. cati study, the primary criterion was the difference between arithmetic mean mite counts of cats treated with Felpreva® and cats treated with a placebo formulation (solketal). Secondary criteria in both studies were changes in clinical lesion scores after treatment. In both studies, all Felpreva®-treated cats were mite-free (100% parasitological cure) on Day 28, 4 weeks after treatment. Signs of mange on Day 28 were clinically improved in all O. cynotis-infested cats (100%) and clinically cured in all N. cati-infested cats (100%). There were no records of any adverse events or application site reactions in Felpreva®-treated cats.

Transcriptome Analysis of Otodectes cynotis in Different Developmental Stages

The mite Otodectes cynotis is distributed worldwide and parasitism the ear canals of cats and dogs, causing otitis externa. Molecular biology of O. cynotis is poorly understood, with only a few genes being deposited in public databases. In the present study, we aimed to perform transcriptome analysis of O. cynotis using SMRT and Illumina sequencing of RNA from different development stages. SMRT-Seq of O. cynotis demonstrated 5,431 final transcripts, including 406 long non-coding RNAs and 2,698 differentially expressed genes (DEGs), including 1,357 up-regulated genes and 1,341 down-regulated genes between adult mites and nymph/larva. A total of 397 putative allergen genes were detected, 231 of which were DEGs. Among them, 77 were homologous of known mite allergens. The expression level of allergen genes hints at the pathogenicity of mites in different life stages, and the protein interaction network analysis could identify possible key genes in the pathogenic mechanism. Intriguingly, Gene Ontology analysis showed that most of the (DEGs) were associated with the terms hydrolase activity and proteolysis. Kyoto Encyclopedia of genes and genomes (KEGG) analysis identified drug metabolism-cytochrome P450 signal pathway as one of the top pathways. SMRT-Seq of the full-length transcriptome of O. cynotis was performed first, and a valuable resource was acquired through the combination analysis with the Illumina sequencing data. The results of our analyses provide new information for further research into Otodectes cynotis.

Current review of isoxazoline ectoparasiticides used in veterinary medicine

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.

Fluralaner as a novel treatment for sarcoptic mange in the bare-nosed wombat (Vombatus ursinus): safety, pharmacokinetics, efficacy and practicable use

Background

Sarcoptic mange causes significant animal welfare and occasional conservation concerns for bare-nosed wombats (Vombatus ursinus) throughout their range. To date, in situ chemotherapeutic interventions have involved macrocytic lactones, but their short duration of action and need for frequent re-administration has limited treatment success. Fluralaner (Bravecto®; MSD Animal Health), a novel isoxazoline class ectoparasiticide, has several advantageous properties that may overcome such limitations.

Methods

Fluralaner was administered topically at 25 mg/kg (n = 5) and 85 mg/kg (n = 2) to healthy captive bare-nosed wombats. Safety was assessed over 12 weeks by clinical observation and monitoring of haematological and biochemical parameters. Fluralaner plasma pharmacokinetics were quantified using ultra-performance liquid chromatography and tandem mass spectrometry. Efficacy was evaluated through clinical assessment of response to treatment, including mange and body condition scoring, for 15 weeks after topical administration of 25 mg/kg fluralaner to sarcoptic mange-affected wild bare-nosed wombats (n = 3). Duration of action was determined through analysis of pharmacokinetic parameters and visual inspection of study subjects for ticks during the monitoring period. Methods for diluting fluralaner to enable ‘pour-on’ application were compared, and an economic and treatment effort analysis of fluralaner relative to moxidectin was undertaken.

Results

No deleterious health impacts were detected following fluralaner administration. Fluralaner was absorbed and remained quantifiable in plasma throughout the monitoring period. For the 25 mg/kg and 85 mg/kg treatment groups, the respective means for maximum recorded plasma concentrations (C_max) were 6.2 and 16.4 ng/ml; for maximum recorded times to C_max, 3.0 and 37.5 days; and for plasma elimination half-lives, 40.1 and 166.5 days. Clinical resolution of sarcoptic mange was observed in all study animals within 3–4 weeks of treatment, and all wombats remained tick-free for 15 weeks. A suitable product for diluting fluralaner into a ‘pour-on’ was found. Treatment costs were competitive, and predicted treatment effort was substantially lower relative to moxidectin.

Conclusions

Fluralaner appears to be a safe and efficacious treatment for sarcoptic mange in the bare-nosed wombat, with a single dose lasting over 1–3 months. It has economic and treatment-effort-related advantages over moxidectin, the most commonly used alternative. We recommend a dose of 25 mg/kg fluralaner and, based on the conservative assumption that at least 50% of a dose makes dermal contact, Bravecto Spot-On for Large Dogs as the most appropriate formulation for adult bare-nosed wombats.

Graphical abstract

Recent Advancements in the Control of Cat Fleas

Simple Summary

The cat flea Ctenocephalides felis felis is the most important pest of domesticated cats and dogs worldwide. This review covers the recent advancements in the control of cat fleas. Over the years, there has been an interest in using ecologically friendly approaches to control fleas. To date, no biological, natural, or cultural means have been discovered that mitigate flea infestations. The recent registration of novel topical and oral therapies promises a new revolution in the control of fleas and ticks and the diseases associated with them.

Abstract

With the advent of imidacloprid and fipronil spot-on treatments and the oral ingestion of lufenuron, the strategies and methods to control cat fleas dramatically changed during the last 25 years. New innovations and new chemistries have highlighted this progress. Control strategies are no longer based on the tripartite approach of treating the pet, the indoor environment, and outdoors. The ability of modern therapies to break the cat flea life cycle and prevent reproduction has allowed for the stand-alone treatments that are applied or given to the pet. In doing so, we have not only controlled the cat flea, but we have prevented or reduced the impact of many of the diseases associated with ectoparasites and endoparasites of cats and dogs. This review provides an update of newer and non-conventional approaches to control cat fleas.