Fipronil Tablets: Development and Pharmacokinetic Profile in Beagle Dogs

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.

Barcoded Asaia bacteria enable mosquito in vivo screens and identify novel systemic insecticides and inhibitors of malaria transmission

This work addresses the need for new chemical matter in product development for control of pest insects and vector-borne diseases. We present a barcoding strategy that enables phenotypic screens of blood-feeding insects against small molecules in microtiter plate-based arrays and apply this to discovery of novel systemic insecticides and compounds that block malaria parasite development in the mosquito vector. Encoding of the blood meals was achieved through recombinant DNA-tagged Asaia bacteria that successfully colonised Aedes and Anopheles mosquitoes. An arrayed screen of a collection of pesticides showed that chemical classes of avermectins, phenylpyrazoles, and neonicotinoids were enriched for compounds with systemic adulticide activity against Anopheles. Using a luminescent Plasmodium falciparum reporter strain, barcoded screens identified 48 drug-like transmission-blocking compounds from a 400-compound antimicrobial library. The approach significantly increases the throughput in phenotypic screening campaigns using adult insects and identifies novel candidate small molecules for disease control.

This study presents a barcoding strategy that enables high-throughput phenotypic screens of blood-feeding insects against small molecules in microtiter plate-based arrays and applies this to the discovery of novel systemic insecticides and compounds that block malaria parasite development in the mosquito vector.

Efficacy of Oral Sarolaner for the Treatment of Feline Otodectic Mange

Otodectes cynotis is a mite with a cosmopolitan distribution that is the primary agent for the development of otitis externa in feline species. The aim of this study was to evaluate the efficacy of the oral administration of sarolaner for the treatment of feline otodectic mange. We used 20 adult cats of both sexes that were naturally infested with O. cynotis. The mite infestation scoring was performed by video-otoscopy before treatment. The cats were randomized according to the infestation score and divided into two groups (treated and control). The treated group underwent oral administration of sarolaner in a single dose of 2-4 mg/kg. The evaluations were performed by video-otoscopy to evaluate the reduction of infestation score 2, 4, 6, 24 and 48 h and 7, 14, 21 and 28 days after medication. At the end of the study, the cats were sedated to enable the recovery of live and dead mites to determine efficacy. No adverse effects or laboratory changes were observed in these cats. Sarolaner showed 100% efficacy 48 h after treatment. Based on the results, a single oral dose of sarolaner was effective in controlling otodectic mange in naturally infested cats.