Professional Opinions

• ‘Anthelmintic resistance in veterinary parasites is a major problem worldwide…..we need to implement strategies to maximize the effective lifetime of our current compounds.’ (Wolstenholme et al (2004) Drug resistance in veterinary helminths. Trends in Parasitology 20, 469-476)

The following quotations are largely made in reference to horses, however the broad concepts are the same for all animal species.

• ‘Checking FEC on a regular basis is the single most important thing you can do to improve your parasite control program.’ (Karen Briggs (2004) Parasite primer: examining the evidence. www.theHorse.com)

• ‘Recipe based treatment programs based solely on the calendar without regard to the medical needs of individual horses, the biology of the parasites, or whether the drug is actually effective against the target parasites can no longer be justified or recommended. An evidence-based medical approach where the biology of the target parasites and the effectiveness of drugs are considered, and each horse is viewed as an individual patient with individual medical needs must be adopted.’ (Kaplan (2010) Update on equine parasites and anthelmintic resistance. NAVC Conference)

• ‘Proper timing and interpretation of quantitative parasite fecal egg counts can be used in adult horses to identify individuals that require treatment as well as monitor for anthelmintic resistance.’

‘Balancing a desire for decreased anthelmintic administration [to minimise development of resistance] while maintaining the health of the horse can only be achieved through the rational application of routine quantitative FEC to differentiate horses that need treatment from those that do not.’ (Swiderski and French (2008) Paradigms for parasite control in adult horse populations: a review. AAEP Proceedings 54, 316-321)

• ‘..it has become increasingly clear that treating all horses at fixed intervals all year round can no longer be considered a valid approach.’

‘It is concluded that treatment strategies need to change and more reliance should now be placed on surveillance of parasite burdens, and regular drug efficacy [effectiveness, FECR] tests are also recommended to ensure continuing drug efficacy.’

‘Presently, the only reliable method for the detection of anthelminthic resistance is a simple faecal egg count reduction test….’ (Nielsen et al. (2010) Practical aspects of equine parasite control: A review based upon a workshop discussion consensus. Equine Veterinary Journal 42, 460-468 (consensus from parasitologists from Denmark, Germany, UK, France, The Netherlands and Spain))

• ‘Millions of tubes of anthelmintic are being administered to horses every year that are killing very few parasites either because there are very few worms in the horse to kill, or because the drug is ineffective as a result of resistance.’ (Kaplan (2010) Update on equine parasites and anthelmintic resistance. NAVC Conference)

• ‘It is obvious that traditional approaches to equine strongyle control are not sustainable. For decades, horse owners and equine practitioners have relied on rote deworming with drugs that may no longer be effective and have mistakenly assumed that frequent, whole-herd treatment was essential for maintaining the health of their charges. The excesses of the past have resulted in significant present threats and future challenges. The tenets of evidence-based medicine demand, at the least, that the spectrum of effective products be elucidated for each equine premise. Further gains in sustainable strongyle control can be made if programs are based on knowledge of local, seasonal transmission patterns and customized for individual horses on the basis of their contaminative status within the herd.’ (Reinemeyer (2009) Controlling strongyle parasites of horses: a mandate for change. AAEP Proceedings 55, 352-360)

• ‘From now on, nematode control programmes should include analysis of drug efficacy by utilising the FECRT.’ (Matthews (2008) An update on cyathostomins: Anthelmintic resistance and worm control. Equine Veterinary Education 20, 552-560)

• ‘We need to move away from an interval treatment regime towards an evidence- based, strategic, and targeted program that will help extend the life of our current arsenal of worming products’ (Beasley (2012) Is your property home to drug resistant worms? Special report in Horses and People; www.horsesandpeople.com.au, 26 September, 2012)

The following quotation refers to sheep:

• ‘There has been a shift away from prescriptive, calendar-based strategic worm control programs for sheep to modified strategic programs with an increased emphasis on integrated parasite management and treatments based on worm egg count monitoring rather than visual assessment or the calendar. Use of effective combinations and drench rotation are recommended. Monitoring of drench efficacy by way of post-drench WEC [worm egg count (= FEC)] in small and large ruminants and alpaca is recommended.’ (Love (2010) Worms – what’s new: some recent developments in worm control in ruminants and camelids. AFBM Journal 7, 45-51)