Limited strongyle parasite occurrence in horses kept in an arid environment

The objective of this study was to document the strongylid infection status of stabled horses residing in an arid environment with limited access to pasture. Faecal parasite examinations were conducted in a private equine practice in Southern California over a period of 7 years, from 2012 to 2018, from a variety of horses in seven different locations; not all horses living at these locations were studied. Results of all faecal examinations were obtained and tabulated, as to both total number of horses examined, as well as individual animals followed with at least four consecutive bi-annual faecal examinations over a 2-year period. A total of 851 faecal tests on 79 individual horses were performed during the 7-year study period, and 78 (9%) were strongyle positive. By the end of the study period, during which horses were monitored and treated according to faecal flotation tests, 97% of 117 faecal flotation tests were negative for strongyle parasites. In conclusion, in a population of 79 adult horses living in dry, arid conditions, with little or no access to pasture, frequent deworming for strongylid parasites would appear to be less necessary than in other environments. Regular faecal monitoring of horses in such conditions is appropriate for determining the necessary level of anthelmintic intervention.