Efficacy of Fluralaner in the Treatment of Sarcoptic Mange (Sarcoptes scabiei) in 12 Pet Rabbits

A systematic review of fluralaner as a treatment for ectoparasitic infections in mammalian species

Fluralaner (Bravecto™) is a novel isoxazoline ectoparasiticide used for controlling ectoparasites of domestic mammals and is increasingly being used on wildlife. The aim of this systematic review was to evaluate the efficacy, pharmacokinetics, and safety of fluralaner on mammals given its increasing use. The search was performed in GoogleScholar and the SciFinder databases using the terms 'fluralaner' and 'Bravecto™', and was concluded on 30th August, 2024. A total of 250 references were initially saved and reduced to 121 peer-reviewed journal articles using PRISMA guidelines, based on the removal of duplicates, those published in low quality journals (ranked less than Q2), and limiting publications to clinical trials. Articles were then categorised and ranked using the level of evidence, Cochrane 'risk of bias' assessment tool, methodological quality, and study size. Overall, the efficacy of fluralaner has been assessed on 14 mammalian species, and pharmacokinetic investigations conducted on 15. Fluralaner was mostly effective at treating some ectoparasites on captive individuals when there was little chance of re-infection; however, it did not prevent bites from blood-sucking ectoparasites and could not prevent blood-borne pathogen transfer to host animals. Very few studies have investigated the pharmacokinetics of fluralaner, and hence were difficult to compare; however, wombats differed greatly from their eutherian counterparts in their Cmax and t½ values and require further investigation. Overall, fluralaner was deemed moderately safe; however, most studies were classified as fair in terms of quality and most studies were based on small or very small sample numbers. Nineteen studies reported side effects, one of which included signs of severe neurological toxicity, with most of the articles not reporting on safety either positively or negatively. Concerns were raised regarding the extended time fluralaner was detected in faeces and subsequently environmental contamination is a concern. No longer-term impacts of the use of fluralaner have been investigated, and wider implications of the use of this ectoparasiticide have not yet been assessed.

Sarcoptic mange in domestic rabbits: Pathogenesis, impact, and control strategies

This review article provides an in-depth examination of sarcoptic mange in domestic rabbits (Oryctolagus cuniculus), a widespread and highly contagious dermatological condition caused by Sarcoptes scabiei var. cuniculi mites. Sarcoptic mange poses significant health risks to rabbits and can lead to severe economic losses in commercial rabbit farming due to decreased productivity, inferior leather quality, and increased mortality rates. Clinical manifestations in rabbits include intense itching, skin lesions, hair loss, and secondary bacterial infections, which can be fatal if left untreated. The immune response in rabbits involves both innate and adaptive components, with keratinocytes playing a crucial role in initiating the response. The adaptive immune response is characterized by a mixed T helper cell profile, leading to inflammation and antibody production, which possibly play a key role in controlling mite infestations. Diagnosis of sarcoptic mange is typically based on clinical signs, supported by microscopic examination of skin scrapings and serological tests. The review emphasizes the risk of transmission to humans, especially those in close contact with infested rabbits, and explores the complex host-parasite immune interplay, detailing how S. scabiei evades the host's immune system through various mechanisms. The review also discusses advanced treatment approaches, focusing on the need for effective control measures to prevent the spread of mange in rabbit populations. The article underscores the importance of further research into the molecular mechanisms of the disease to develop targeted therapeutic interventions.

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.

Zoonotic Dermatoses of Exotic Companion Mammals

Integumentary disorders caused by zoonotic agents are very common in exotic companion mammals. This article provides an understanding of the main zoonotic dermatoses including parasitic, fungal, bacterial, and viral diseases to provide the most updated information on their epidemiology, diagnosis, reported clinical signs, and therapies.

Problem-Oriented Approach in Exotic Companion Mammals

Dermatologic disorders are some of the most common conditions affecting exotic companion mammals. This article provides a clinical approach of the conditions presenting with alopecia, pruritus, scaling/crusting, erosion/ulceration, and nodules in order to select and interpret the appropriate diagnostic tests to achieve a diagnosis for a successful treatment.

Rabbit Dermatology

The majority of rabbit skin disease presentations can be divided into pruritus, alopecia, scaling, and nodules. Some disease will have more than one of these clinical signs. Ectoparasites, bacterial and fungal infections, and neoplasia account for most of the causes seen. Diagnostic tests include skin scraping and cytology, microbial culture, and biopsy. Therapy is dependent on cause. In addition to discussing the various causes and their treatments, important clinical care points are noted.

Efficacy of a spot-on combination of fluralaner plus moxidectin against naturally acquired Sarcoptes scabiei infestation in 10 pet rabbits: Retrospective case series

BACKGROUND

Current treatments for sarcoptic mange in rabbits mainly include administration of avermectines every 10-30 days. Recently, a single oral dose of fluralaner has been shown to be effective to treat sarcoptic mange in 12 pet rabbits over a three-month period.

OBJECTIVES

To retrospectively assess the efficacy of a spot-on combination of fluralaner plus moxidectin (Bravecto Plus) for the treatment of sarcoptic mange in rabbits.

ANIMALS

Ten client-owned rabbits diagnosed with sarcoptic mange.

MATERIALS AND METHODS

An application of fluralaner plus moxidectin at an average dose of 25 mg/kg and 1.24 mg/kg, respectively, was administered topically once. Parasitological and dermatological examination was carried out weekly for one month and monthly for three months.

RESULTS

The median age at diagnosis was 15 (range 3-48) months. Based on the age of onset, there were three juvenile (<6-month-old) and seven adult-onset cases. Of those, four were generalized (head, feet and/or genital area) and six were localized form (head only). The combination of fluralaner plus moxidectin resulted in 100% eradication of mites and complete resolution of all skin lesions within 21 days. Recurrence was not observed 90 days post-treatment. Relapse was not observed in one case followed up for a further four months and two rabbits followed up for a further six months. The other pets were lost to follow-up.

CONCLUSIONS AND CLINICAL RELEVANCE

These results indicated that a single dose of a formulation containing fluralaner plus moxidectin, at 25 mg/kg and 1.24 mg/kg, respectively, was effective for the treatment of naturally occurring sarcoptic mange in rabbits.

Structural modification of octadecanoic acid-3,4-tetrahydrofuran diester and the acaricidal activity and mechanism of its derivatives against Sarcoptes scabiei var. Cuniculi

Octadecanoic acid-3,4-tetrahydrofuran diester is a compound with acaricidal activity isolated and extracted from neem oil. In this study, a series of derivatives were obtained by structural modification of octadecanoic acid-3,4-tetrahydrofuran diester. The acaricidal activity of these derivatives indicated that introduction of benzyloxy substitution at the 2-position of the furan ring and the formation of a benzoate at the 3,4-position of the furan ring (benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester) could enhance the acaricidal activity. At concentration of 20, 10, and 5 mg/ml, the median lethal time (LT50) values of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester were 16.138, 47.274, and 108.122 min, respectively. The LC50 value of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester at 60 min was 5.342 mg/ml. Transmission electron microscopy showed that after treatment with benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester, the body structure of mites was destroyed; dermal organelles were dissolved; nuclear chromatin was ablated. Further, transcriptome sequencing analysis was used to get insight into the acaricidal mechanism of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester. The results showed that its acaricidal mechanism is related to interfering "energy metabolism" in S. scabiei, including processes such as citric acid cycle, oxidative phosphorylation pathway and fatty acid metabolism. Additionally, through the activity detection of the mitochondrial complexes of S. scabiei, it was further verified that the acaricidal mechanism of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester was related to the energy metabolism system of S. scabiei.

A rapid evidence assessment of the potential risk to the environment presented by active ingredients in the UK's most commonly sold companion animal parasiticides

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.