Where there’s muck, there’s brass: effective deworming

Responsible anthelmintic use is not the most glamorous or exciting of topics and it is easy to switch off. However, deworming is something most horse owners think about on a regular basis and it therefore provides a recurring opportunity to engage with them for the common good and good of the practice (Figure 1).

Tangible financial benefits exist for targeted worming regimens, both for the practice and the horse owner, so it is something practices should embrace. Furthermore, moves toward equine anthelmintics becoming prescription only medicines are occurring, so practices that haven’t already done so may want to implement strategies of worm control sooner rather than later.

Marketing benefits

Questionnaire surveys of horse owners have indicated most value the opinion of their vet when it comes to worming, but few use their vet as their primary source of advice¹. This, therefore, provides an opportunity for forward-thinking practices that are aiming to promote regular interaction with their clients, whether in person or via social media.

It is also an easy win as it is straightforward to provide advice that is far more useful and reliable than horse owners receive elsewhere.

The level of understanding of anthelmintic use among horse owners has been demonstrated to be poor, even among those who regularly perform faecal worm egg counts (FWECs). Sadly – in the author’s experience, at least – much of the advice owners receive from suitably qualified persons working in equine retail outlets or from online worm egg count providers is also poor and can undermine attempts to use anthelmintics more responsibly.

Incorporation of deworming advice, testing and treatment in annual health care or preventive medicine packages also provides an opportunity to remain a step ahead.

Financial benefits to practices

In 2015, equine anthelmintic sales in the UK were worth more than £13 million and only £1.3 million of sales went through veterinary practices – less than 10%.

A total of 55% of sales through veterinary practices were moxidectin, which suggests sales through veterinary practices are more focused on treatment than prevention.

The majority of purchases were made via trade retail outlets (£10 million) with the remainder being sold by online pharmacies (£2.2 million). Not only are vets responsible for a very small proportion of total sales, but our market share appears to be declining as it dropped 16% between 2014 and 2015 compared to an 8% drop in sales via trade retailers.

The drop is hopefully an indication more responsible strategies of deworming are being adopted, but a growing disconnect may also be occurring between vets and horse owners with respect to deworming.

Anthelmintic sales through practices are worth around £850 per equine vet. If anthelmintic sales were made solely via vets then this would increase 10-fold to £8,500 per vet – not a fortune, but enough to make it worth the effort of selling them. In addition to the value of the anthelmintics, potentially greater value exists in the diagnostics that are integral to targeted deworming plans.

Tests for antibodies to Anoplocephala (tapeworms) in either blood or saliva are available, but offer poor cost-benefit when:

• they are many times more expensive than the cost of treatment
• resistance to tapeworms is of less concern than resistance in roundworms

FWECs, which determine the number of nematode eggs in faeces, are central to targeted worming strategies and can provide a valuable source of revenue for the practice, even if counts are not performed in house.

In the author’s laboratory, FWECs cost between £4 and £7, inclusive of postage, depending on the number being submitted by the yard or referring practice.

This is deliberately less than horse owners pay through online providers (typically £7 to £10) to enable veterinary practices to be competitive and leave them with margin to incorporate FWECs into their own plans and compete with other providers.

If FWECs are run in-house then greater potential may exist for profit, but the cost of a staff member performing four to eight counts per hour has to be considered – especially if the throughput is inconsistent and the process, therefore, potentially inefficient.

Rainbow Equine Hospital, where the author works, implemented a programme of targeted worming at the beginning of 2016, in which horse owners paid for four FWECs and an autumn wormer at the beginning of the year. This generated more than £3,000 turnover per vet at the start of the year, with further horses joining the programme on an ad hoc basis through the year.

Clients who signed up to the programme were given preferential rates on anthelmintics (if they needed them), which resulted in around a 500% increase in anthelmintic sales (from a very low starting point). With estimates of the number of anthelmintic doses likely to be required to treat the horses enrolled on the plan, deals were negotiated with manufacturers at the start of the year, which enabled the practice to beat internet pharmacy prices while retaining the same profit margin.

The deworming programme has also had the indirect benefits of introducing new clients to the practice and facilitating discussion and introduction of other preventive medicine measures that should be implemented on yards, such as vaccination and testing for strangles.

Many different approaches exist to packages of FWECs with or without anthelmintics. The aforementioned approach is open to criticism as it assumes at least one dose of anthelmintic will be administered per annum. In some situations, this may be unnecessary, but few vets and owners are prepared to give up the comfort blanket of a single dose of anthelmintic aimed at larval cyathostomins in the autumn.

Most work associated with organising deworming plans and dewormer sales can be performed by non-vets in the practice. The administrative burden of running targeted worming programmes can be reduced by using internet-based technologies and this also provides a further opportunity to engage clients with the practice’s website and social media platforms.

A smartplanner has been available for horse owners to use for a number of years, but can now be set up via practice websites to provide a means of displaying and storing FWEC data, where it can be seen by both the practice and its clients (Figure 2).

Financial benefits to owners

In addition to the obvious benefit of reducing the risk of anthelmintic resistance on a property with the long-term implications this may have, direct financial benefits exist to horse owners of adopting targeted worming strategies.

In 2013, a comparative analysis was published that assessed the financial impact of applying targeted anthelmintic treatments across 16 yards in the UK containing 368 horses². Horses were either treated with two doses of moxidectin and two doses of moxidectin/praziquantel combination per annum, or were treated in a targeted manner. The targeted programme included three FWECs in February/March, June/July and September/October, in which all horses with a FWEC greater than 200 eggs per gram were treated with ivermectin or pyrantel.

All horses were then treated with moxidectin/praziquantel in December. All horses in the targeted group also had a FWEC reduction test performed to assess anthelmintic efficacy. Every yard made a saving, which ranged from £57 to £568 (Figure 3). On average, this was a saving of £13 per horse. This may not be a massive difference, but it provides valuable evidence to overcome owners’ primary objection to engage with targeted worming programmes that it will end up costing them more.

A host of variables will affect the economics of implementing targeted worming programmes – the age of the horses, the chosen cut-off for treatment, as well as the cost of the anthelmintics and FWEC. Some of these factors were investigated in a French herd of ponies in which FWEC were performed over a period of four years and the resulting data was modelled to assess the impact of different variables on overall costs of targeted worming³.

Some major differences occurred from the UK, with both FWECs and anthelmintics being considerably more expensive in France. Even when the time taken to collect faecal samples was taken into consideration and a large number of immature horses with higher burdens were present in the population, targeted worming was cost-effective when FWECs cost €5 (£4) or less.

In line with previous studies, anthelmintic use reduced by 78% when the targeted strategy was adopted. Sallé et al (2015) also looked at the impact of pooling faecal samples to try to further reduce the cost of targeted worming.

Costs were reduced, but false-negative results (individuals with high egg counts being missed) were common, compromising the effectiveness of the targeted approach and leaving some animals with high burdens untreated – a concern in a client-owned population where the health of individual animals has to remain paramount.

Conclusions

The fact numerous variables need to be considered when implementing targeted worming programmes highlights the value and importance of veterinary involvement. We are trained to have a greater level of understanding of the wider issues of anthelmintic use than those who are trained, to be able to sell wormers in the retail sector.

We are likely to have a better understanding of the management of the yard, levels of resistance in the area and how this impacts on parasite control.

Implementing strategies of targeted worming is not only a professional responsibility, given increasing levels of anthelmintic resistance, but brings direct and indirect marketing and financial benefits that more than compensate for the additional workload.