Comment on: “The treatment of sarcoptic mange in wildlife: a systematic review”

Abstract

This letter comments on the article “The treatment of sarcoptic mange in wildlife: a systematic review” published in Parasites & Vectors 2019, 12:99, and discusses the limitations in the use of endectocides for scabies control in free-ranging wildlife. The ecological impact and drug resistance to ivermectin are also discussed. In our view, scabies control in free-ranging wildlife should be based preferably on population management measures, and whether to apply individual treatments to free-ranging populations should be considered very carefully and avoided where not absolutely warranted.

First description of sarcoptic mange in an Iberian hare (Lepus granatensis)

“…The present report in a previously undetected host of S. scabiei , the Iberian hare, should raise awareness in wildlife operators and veterinary authorities, and stimulate monitoring programmes in areas where this endemic game animal shares range with endemically infected wild rabbits ( Moroni et al., 2020 ). The role of restocking as a risk factor for the spread and persistence of sarcoptic mange in wild rabbits and sympatric lagomorphs should also be elucidated in the future.…”

Sarcoptic mange outbreak decimates South American wild camelid populations in San Guillermo National Park, Argentina

“…High conservation value species affected by mange have been treated with medication (e.g., ivermectin, fluralaner) [86][87][88][89]. Yet data on efficacy, pharmacokinetics, and other basic aspects of these therapeutic drugs is lacking for most wild species, and few interventions have succeeded in eliminating mange after a single dose or been possible in free-ranging conditions [90,91]. In wild settings, relay toxicity of drug residues to predators and scavengers must be considered, as well as environmental toxicity.…”

Ivermectin Plasma Concentration in Iberian Ibex (Capra pyrenaica) Following Oral Administration: A Pilot Study

“…The controlled conditions of the experiment will allow the use of the results as reference for future experimental scenarios and/or field studies. Sarcoptic mange has been pharmacologically treated in captive wildlife, and some experiences in freeranging wildlife populations have also been carried out, mostly empirically (8,10,23).…”

“…Amongst other measures like non-intervention (laissez-faire), massive lethal control, and selective culling of clinically-affected animals (7), individual and mass treatments with acaricides have been proposed and empirically implemented at local scale with unknown success (8). However, beyond ethical considerations, treating free-ranging wildlife has disadvantages, such as the impracticability of drug administration on a large population scale, and the potential environmental contamination with drug residues (9,10). In Spain, the lack of shared protocols among regions to tackle the population decline caused by sarcoptic mange in exposed wild ruminants has promoted the empirical use of acaricides massively administered through medicated mixture feed (6).…”