Benefit of targeted worming

Worming only those horses that need it can be cost effective, even taking into account the cost of performing faecal worm egg counts, according to research published in the Veterinary Record.

It is now widely acknowledged that a targeted approach to worm control is preferable to interval dosing regimes. Current recommendations are that only those horses carrying a moderate or high worm burden are treated; thus ensuring that worms are not exposed to anthelmintics needlessly.

Faecal worm egg counts (FECs) are used to determine which horses need (or don't need) treating. To many owners this may seem an unnecessary expense. However, recent work has shown that using FECs in this way helps reduce the overall cost of worming.

Hannah Lester, with colleagues at the Moredun Research Institute, and the Universities of Bristol, Liverpool and Edinburgh, monitored FECs at 3 monthly intervals over a nine month period. In all, 368 horses from 16 separate yards were involved in the study.

Horses with FECs greater than 200epg were treated, with pyrantel (in March and June) and ivermectin (in September). All horses received moxidectin/praziquantel in December.

The researchers compared the cost with that of a standard interval regime of two treatments with moxidectin and two of moxidectin and praziquantel - which is what had been common practice in the study population.

They  estimated the cost of the two approaches by using average prices for anthelmintic products and faecal egg counts that they obtained off the internet. Even allowing for the cost of faecal egg count reduction tests  (ie repeating the FEC after each treatment to check the anthelmintic had been effective)  they found that, over the year, there was an average saving per yard of £294.44.

They conclude: “these findings support the notion that targeting anthelmintic treatments at those individuals with strongyle FEC of 200epg or greater facilitates a reduction in selection pressure for anthelmintic resistance. Moreover, the results show that such a strategy has a high chance of reducing the financial cost compared with that associated with more traditional interval treatment regimens, and horse owners should, therefore, be discouraged from the view that it is cheaper to treat all horses prophylactically over time.”

Read more: equinescienceupdate.com