A survey on parasite management by equine veterinarians highlights the need for a regulation change

Abstract

Introduction: In-depth knowledge of the use of anthelminthics in the field, especially by veterinarians, is required to design more sustainable parasite control strategies.

Materials and methods: An online survey was sent by e-mail to 940 equine veterinary practitioners to describe their equine practice, their awareness about parasites and the management strategies they apply.

Results: Gastrointestinal parasites were generally considered (68%) as an issue of moderate importance. Drug efficacy failure was a minor or moderate issue for 47% and 48% of responders, respectively. Parasite management mostly relied on the use of systematic calendar treatments across a wide variety of horse owners (ie, riding schools, studs or hobby horse owners). Almost half of the practitioners (42%) never performed Faecal Egg Count (FEC) before drenching. Horse owners or their employees in charge of equines were reported to be the only person managing drenching in 59% of the collected answers. This was associated with the report of many off-label uses of anthelmintics and the frequent buying of drugs using the internet.

Conclusions: Given the critical situation regarding anthelmintic resistance, it seems necessary for veterinarians to reclaim parasite management and prevention as a specific topic. Implementation of stricter regulations for use of anthelmintics, like the one applied in Denmark, may make parasitic management in equids more sustainable.

Keywords: Anthelmintics; Horses; Resistance; parasite control; questionnaire.

FIG 1:

Basic description of the responders. This figure draws a picture of the main characteristics associated with responders’ practice by plotting distributions of the practice sizes (a), the ages of responders (b), the proportion of horses in practice (c) and the total number of horses in practice (d). In each case, a bar plot is provided that indicates the count of responders falling in one of the indicated categories (total count of 91 responders)

FIG 2:

Drug use. This figure illustrates common usage of anthelmintic compounds according to responders (n=91 in total). Stack bar plots, corresponding to the count of responders who answered ‘yes’ (in green) or ‘no’ (in black), illustrate the way drenching decision is made (a), how the anthelmintic compound is chosen (b), what anthelmintic compound is used (a) or the situations where drenching is performed without performing prior faecal egg count (FEC; c). BZL, benzimidazole; FECRT, Faecal Egg Count Reduction Test; IVM, ivermectin; MOX, moxidectin; PYR, pyrantel; PZQ, praziquantel.

FIG 3:

Risk factors potentially associated with drug failure. This figure describes the relative frequency of the person in charge of drenching (veterinarian (1 per cent of responders), horse owner (59 per cent of responders) or both (40 per cent of responders)) on (a). The frequency of some potential risk factor in the use of anthelmintic compounds is also illustrated through a stacked bar plot about the awareness of off-label use (b) and the distribution of the estimated proportion of clients (given by responders; listed on the x-axis as a percentage value) buying their anthelmintic drugs from the internet (c). In each case, plots are based on a total count of 91 responders