9th ICEID Abstracts / Journal of Equine Veterinary Science 32 (2012) S3-S95 S49

simultaneously at frequent intervals is still common inFinland, even though horse practitioners are nowpromoting the use of targeted selective treatment. In orderto evaluate selective therapy as an option to reduceanthelmintic use we conducted a study on ten stables.Objectives: 1. To estimate parasite loads of individualhorses 2. To analyse risk factors for high egg counts 3. Toobserve the effects of different anthelmintics to the indi-vidual parasite loads. One to eight fecal samples per horsewere collected from 215 (86 geldings, 100 mares, 24 stal-lions) horses (mean age 9.1 yrs, min 0 and max 29) fromten stables in Finland during a one-year study period. Thesamples were analysed by modified McMaster-techniqueby the Finnish Food Safety Authority (Evira). Antiparasitictreatment history of each horse was collected by a ques-tionnaire. Majority of the adult horses maintained lowepg-values (<200) throughout the study period. Epg-values of young horses (<4 year-olds) were significantlyhigher than those of adult horses. Post antiparasitictreatment epg-values increased more rapidly in younghorses than in adults. Young age and being a mare orstallion are risk factors for high egg counts. The egg counthas a negative linear relationship with age. No higher eggcount was observed in the oldest age group (>20 years).Majority of the adult horses are able to maintain low epg-values and therefore frequent treatments with anthel-mintics to all horses should be discouraged. Horses shouldbe sampled and treated based on individual risk factorsand epg-values. Further analysis of the data will bringmore information on how the risk of high epg-count isaffected by grazing, season and treatment intervals.

Factors influencing the magnitude of strongyle egg-shedding in horses

A. Honeder 1,2, A.M. Becher 2, M. Reist 3, and K. Pfister 21 Pferdepraxis Dr. Müller, D-83395 Freilassing, Germany,2 Comparative Tropical Medicine and Parasitology, Vet.Faculty, Ludwig – Maximilians -University, D-80802Munich, Germany, 3 Veterinary Public Health Institute,Vetsuisse-Faculty, University of Berne, CH-3097 Liebefeld,Switzerland

A relatively new approach in equine worm control is tar-geted selective treatment. Using this method only thosehorses are treated with anthelmintic drugs, which are

shedding a high number of strongyle eggs. The aim of thisstudy was to evaluate the influence of different factors onthe magnitude of strongyle egg-shedding in horses. Faecalsamples were collected in 2009 from 314 horses from 35farms located in the Austrian-Bavarian border area ofSalzburg. Altogether, 2703 samples were analysed usinga modified McMaster Method (sensitivity: 20 eggs pergram feces) Additionally, the following data was collectedfor every horse/sample/farm: age, sex, breed, faecal eggcount (FEC) data from the previous year, management andhygiene procedures, previous deworming methods anddata about climatic conditions before and during thesampling period. With all variables, a univariate PoissonRegression was performed. Variables with a statisticallysignificant influence on the magnitude of strongyle eggshedding were included into a multivariate PoissonRegression model and a backward-elimination was per-formed. The following variables remained in the multi-variate model and were positively associated with thelevel of the strongyle FEC: mean strongyle FEC in 2008,mean strongyle FEC of the horse population on the samefarm, mean strongyle FEC of the pasture-mates, size oflarge paddocks and number of months since the lastanthelmintic treatment). Negatively associated was theage. The effect of hygiene of pasture and of large paddockson FEC was not consistent. The parameters hygiene ofstables and paddocks/bedding of stables/drug class of thelast anthelmintic treatment and breed were not signifi-cantly associated with the FEC, but remained in themultivariate model as confounders. These results confirmthat a reduction of the mean strongyle FEC of pasture-mates can reduce the magnitude of the strongyle FEC ofindividual horses. This is a very important argument forfurther developing the method of selective anthelmintictreatment in horses.

The influence of anthelmintic treatment on strongylid(Nematoda: Strongylidae) community structure indomestic and wild equids

T.A. Kuzmina 1, E.T. Lyons 2, S.C. Tolliver 2, andV.A. Kharchenko 1

1 Institute of Zoology NAS of Ukraine, vul. B.Khmelnyts’kogo, 15, Kyiv, 01601, Ukraine, 2 Department ofVeterinary Science, Gluck Equine Research Center,University of Kentucky, Lexington, KY 40546-0099, USA

Strongylids (Nematoda: Strongylidae) are the group ofparasites of domestic and wild equids worldwide. Threegroups of anthelmintics (benzimidazoles–BZs, tetrahy-dropyrimidines–PYR, and macrocyclic lactones) arewidely used to control horse strongylids nowadays. Theaim of our work was to analyze the influence of differentparasite control schemes on the biodiversity and struc-ture of strongylid communities in domestic and wildequids. Our studies were performed during 2004–2011 on69 domestic horses from various types of horse farms inUkraine, 31 donkeys from a natural reserve and privatefarm, and 29 wild Przewalski’s horses kept at the “Aska-nia-Nova” reserve and in zoos. Animals had undergone