The current status and outlook for insecticide, acaricide and anthelmintic resistances across the Australian ruminant livestock industries: assessing the threat these resistances pose to the livestock sector

Abstract

The Australian ruminant livestock industries are faced with the need to control parasitic infectious diseases that can seriously impact the health of animals. However, increasing levels of resistance to insecticides, anthelmintics and acaricides are substantially reducing the ability to control some of these parasites. Here we review the current situation with regard to chemical resistances in parasites across the various sectors of the Australian ruminant livestock industries and assess the level of threat that these resistances pose to the sustainability of these sectors in the short to long terms. We also look at the extent to which testing for resistance occurs across the various industry sectors, and hence how well‐informed these sectors are of the extent of chemical resistance. We examine on‐farm management practices, breeding of parasite‐resistant animals, and non‐chemical therapeutics that may act as short to long term means to reduce the current reliance on chemicals for parasite control. Finally, we look at the balance between the prevalence and magnitude of current resistances and the availability and adoption rates of management, breeding and therapeutic alternatives in order to assess the parasite control outlook for the various industry sectors.

First evaluation and detection of ivermectin resistance in gastrointestinal nematodes of sheep and goats in South Darfur, Sudan

“…Ivermectin resistance is a severe problem regarding nematodes of ruminants in many geographic regions and the problem is considered a substantial threat for animal health and productivity worldwide [40]. While evidence of ivermectin resistance in sheep and goat parasites is widespread in commercial breeding systems [41], only a limited number of reports are available from Africa [42, 43]. However, in order to limit the spread of anthelmintic resistance, the extend of the problem needs to be precisely described to develop promising intervention strategies.…”

“…Remarkably, in Europe occurrence of ivermectin resistance in goats has been described from regions such as Czech Republic, Germany, Romania and United Kingdom [12, 50–52]. Also, ivermectin resistance has been identified as problematic for small ruminant farming in Australia [41] and parts of Asia, including China [53], Malaysia [54] and Pakistan [55]. Noteworthy, pasture contamination with nematodes resistant to ivermectin has dramatically increased in Africa as many reports documented the development of resistance in the last decade, particularly for subsistence farming systems, including Ethiopia [13], Nigeria [15] and Uganda [16].…”

First evaluation and detection of ivermectin resistance in gastrointestinal nematodes of sheep and goats in South Darfur, Sudan

“…Ivermectin resistance is a severe problem regarding nematodes of ruminants in many geographic regions and the problem is considered a substantial threat for animal health and productivity worldwide [ 42 ]. While evidence of ivermectin resistance in sheep and goat parasites is widespread in commercial breeding systems [ 43 ], only a limited number of reports are available from Africa [ 44 , 45 ]. However, in order to limit the spread of anthelmintic resistance, the extend of the problem needs to be precisely described to develop promising intervention strategies.…”

“…Remarkably, in Europe occurrence of ivermectin resistance in goats has been described from regions such as Czech Republic, Germany, Romania and United Kingdom [ 13 , 52 – 54 ]. Also, ivermectin resistance has been identified as problematic for small ruminant farming in Australia [ 43 ] and parts of Asia, including China [ 55 ], Malaysia [ 56 ] and Pakistan [ 57 ]. Noteworthy, pasture contamination with nematodes resistant to ivermectin has dramatically increased in Africa as many reports documented the development of resistance in the last decade, particularly for subsistence farming systems, including Ethiopia [ 14 ], Nigeria [ 16 ] and Uganda [ 17 ].…”