Efficacy of afoxolaner (NexGard®) on the treatment of myiasis caused by the New World screwworm fly Cochliomyia hominivorax (Diptera: Calliphoridae) in naturally infested dogs.

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.

Repellent efficacy of a new combination of fipronil and permethrin against Lutzomyia longipalpis.

BACKGROUND: Lutzomyia longipalpis is the main vector of Leishmania infantum, the agent of canine and human visceral leishmaniosis in the Americas. Considering that the dog is the main domestic host of the parasite, repellent treatment is a measure that might contribute to the prevention of canine visceral leishmaniosis. The repellent efficacy of a single treatment of a new spot-on topical combination of fipronil and permethrin (Frontline Tri-Act®, Merial, now part of Boehringer-Ingelheim) to repel Lu. longipalpis sand flies was evaluated. METHODS: Sixteen healthy Beagle dogs, eight females and eight males, weighing 8.4-14.4 kg, and 2 to 4 years-old were included in the study. Animals were blocked on decreasing body weight and randomly allocated within the blocks to one of two treatment groups of eight animals each. Dogs in Group 1 were untreated and Dogs in Group 2 were treated with a combination containing 67.6 mg/ml fipronil + 504.8 mg/ml permethrin (Frontline Tri-Act®) once on Day 0. Sand fly exposures were performed on Days 1, 14, 21 and 30 with Lu. longipalpis female sand flies. After 65 (± 15 min), sand flies were assessed for engorgement status. RESULTS: The percent repellency of the treated group compared to the untreated control group was 95.7, 94.3, 81.7 and 72.2% for exposure days 1, 14, 21 and 30, respectively. The two treatment groups were significantly different for all exposure days (P ≤ 0.016 for days 1, 14, 21 and 30). No adverse reactions were observed during the study. CONCLUSION: A single topical administration of a new combination of fipronil and permethrin demonstrated a significant repellent effect against Lu. longipalpis bites as soon as it was applied on the dogs and its repellent efficacy lasted for 4 weeks with results greater than 80% for 3 weeks. The results suggest that in endemic areas the regular application of the new combination could contribute to protect dogs from Leishmania infection and therefore serve as an additional tool for the prevention of canine visceral leishmaniosis.

Double use of microwaves in fatty acid preparation for elaidic acid determination as phenacyl ester using high-performance liquid chromatography in Brazilian fat products.

Brazilian samples of fat products like margarines, butters and chocolates were prepared to reversed-phase high-performance liquid chromatography analysis, using a domestic microwave oven for fat hydrolysis and derivatization with phenacyl chloride. The total reaction time was 6 min, recoveries were above 94%. Total reproducibility for whole procedure were 3.5% R.S.D. for elaidic acid (n=3), the total chromatography analysis was 25 min.