Strongyle faecal egg counts in Swiss horses: A retrospective analysis after the introduction of a selective treatment strategy

The standard parasite management of horses based on regular anthelmintic treatments, now practiced for decades has resulted in a worrying expansion of resistant helminth populations, which may considerably impair control on the farm level. The aim of the present study was to obtain a retrospective (year 2010 - 2016) nationwide analysis of faecal egg count (FEC) data from the Swiss adult horse population, related to horse age and geographic region. Thirteen labs provided a total of 16,387 FEC data of horses aged four to 39 years (average: 13.6 years). The annual number of performed FEC tests increased from 38 to 4,939 within the observation period. Independent of the annual sample size the yearly patterns of the FEC were very similar. Seventy-eight percent (n = 12,840) of the samples were negative and 90 % (n = 14,720) showed a FEC below 200 strongyle eggs per gram (EPG) of faeces. The annual mean strongyle FEC ranged between 60 and 88 EPG with a total mean of 75 EPG. Horses aged 4-7 years showed a significantly (p < 0.00001) higher mean FEC compared with the other age groups, differences were not significant among the older horses. Based on ZIP codes, samples were allocated by 70.0 %, 6.0 % and 0.2 % to the German-, French- and Italian-speaking regions of Switzerland, respectively. With 222 EPG the mean FEC in the French part of Switzerland was significantly higher (p < 0.05) than in the German-speaking region (60 EPG). Eggs of Parascaris spp., anoplocephalids and Strongyloides westeri were found in 0.36 %, 0.32 % and 0.01 % of the samples, respectively. Based on 3,813 questionnaire feedbacks from owners in 2017 covering a total of 12,689 horses, sixty-eight percent (n = 8,476) were dewormed without diagnosis, two percent (n = 240) were not dewormed at all, whereas for 30 % (n = 3,721) the selective anthelmintic treatment (SAT) concept was applied. The SAT implementation rate differed significantly (p < 0.0005) between regions, with 33 %, 20 % and 25 % for the German-, French- and Italian-speaking areas, respectively. The rate of horses spending 16-24 h on pasture per day was significantly higher in the French-speaking region compared to the German-speaking part of Switzerland (p < 0.0001). In addition, pasture hygiene was practiced at a significantly lower rate in the French-speaking part compared to the German- and Italian-speaking regions (both p < 0.0001). Overall, the shift towards the SAT-concept represents a very promising development with respect to mitigating the further spread of anthelmintic resistance.

[CliniTox: the computer-based information system for poisoning in farm animals]

Poisonings can cause reduced performance and severe economic loss in farm animals. A swift and targeted action is required from veterinarians. We have established a computer-based decision support system for poisonings in ruminants and pigs. The system offers access to the most recent information available in clinical toxicology of farm animals. Towards this goal, relevant reports from the peer-reviewed literature were evaluated and organised according to the requirements of a structured database. The information provided for each toxic substance includes a summary of its chemical and physical properties, sources, commercial uses or natural occurrences, toxicokinetic data, mechanisms of action, threshold doses, clinical symptoms with brief case reports, sampling and analytical results, post-mortem abnormalities, differential diagnoses, therapeutic guidelines and references to the literature. This decision support system has been programmed with two user-friendly search functions: a search tool that allows the choice of clinical and pathological findings, and another function that serves to find a substance using its chemical name, the class of compounds to wich it belongs, a possible source or one of its main applications. CliniTox can be accessed directly via our webserver (http://www.clinitox.ch).