{"id":72,"date":"2010-10-17T15:06:05","date_gmt":"2010-10-17T15:06:05","guid":{"rendered":"http:\/\/www.performanceequinevets.com\/web\/?page_id=72"},"modified":"2019-08-09T18:54:01","modified_gmt":"2019-08-09T18:54:01","slug":"parasites","status":"publish","type":"page","link":"https:\/\/www.performanceequinevets.com\/web\/services\/internal-medicine\/parasites\/","title":{"rendered":"Parasites"},"content":{"rendered":"

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Parasite control is not as straight forward as one would imagine.\u00a0 This is the precise reason you have many different “opinions” as to what the appropriate parasite control method should be. Reaching a balance between parasite load, anthelmintic resistance, and general knowledge is our goal. There is no way to completely eliminate parasites from your horse, but we can help you manage a program which will ensure a long healthy life for your animal and\/or herd.<\/p>\n

Performance Equine Vets Parasite Control Guidelines<\/b><\/span><\/span><\/p>\n

Traditional parasite control programs involve rotating treatment with anthelmintics at regular intervals. This approach is based on concepts and strategies developed more than 40 years ago. Frequent anthelmintic treatments are not needed to keep adult horses healthy. What is needed are properly timed treatments with effective anthelmintics administered at appropriate times of the year.<\/span><\/p>\n

What are fecal egg counts used for?<\/span><\/p>\n

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    Clinical Diagnosis?<\/b>– For example if your horse is colicing and parasites are a suspected culprit, a fecal egg count can be done to support that diagnosis and to determine the exact type of parasite causing the problem, and therefore help the clinician target a treatment protocol for the patient. However, a negative fecal egg count does not mean your horse does not have parasites causing the problem. High specificity (can be as high as 98%), moderate sensitivity (can be as low as 72%), Negative Predictive Value (can be as low as 66%- these are horses that have a negative fecal egg count and this is the percent that are actually truly negative). This means fecal egg counts may not be valuable in clinical diagnosis.<\/span><\/p>\n

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    Fecal Egg Count Reduction Tests<\/b>– To help determine if a dewormer used is efficacious and if it is working to reduce the parasite load. This is the most important use of the fecal egg count in the horse.<\/span> This is however done on the herd level, this is not effective for use in the individual horse. We like to have 6 horses if possible for this test. The anthelmintic in question is administered and a fecal sample is collected 14 days following treatment. <\/span><\/p>\n<\/li>\n<\/ol>\n

    % Efficacy = (Pre-trt EPG- Post-trt EPG)\/ Pre-trt EPG X 100 = % Efficacy of De-Wormer used<\/span><\/p>\n

    Anthelmintic<\/span> \u00a0 \u00a0 \u00a0 Expected Efficacy if No Resistance<\/span> \u00a0 \u00a0 Susceptible<\/span> \u00a0 \u00a0 Suspected Resistance<\/span> \u00a0 \u00a0 Resistance<\/span><\/span><\/p>\n

    Fenbendazole: \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a099% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 >95% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 90-95% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <90%<\/span><\/p>\n

    Pyrantel: \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a094-99% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 >90% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 85-90% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0<85%<\/span><\/p>\n

    Ivermectin\/Moxidectin: \u00a0 \u00a0 \u00a0 \u00a0 99.9% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0>98% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a095-98% \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 <95%<\/span><\/p>\n

    *Strongyle resistance to ivermectin or moxidectin has not been diagnosed in the US to date. Therefore, any FECRT result that yields <95% reduction for these drugs should be repeated before concluding there is resistance.<\/i><\/span><\/p>\n

    It is recommended to include at least six horses in a FECRT on each farm. Further, it is recommended to always recruit the horses with the highest possible pre-treatment egg count for the FECRT. Horses should not have received anthelmintic treatment at least 9 weeks prior to the FECRT a<\/i>fter benzimidazoles (fenbendazole\/oxibendazole) or pyrantel was used, after 12 weeks if an ivermectin was used, <\/i><\/span>(preferably 16 weeks, if moxidectin was used). FEC are quite variable, so if testing is done with few horses there is potential for variability, which could lead to an incorrect inference. Therefore, borderline results should be interpreted with care, and the test should be repeated before any conclusion is made.<\/i><\/span><\/span><\/p>\n

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      Determination of Egg Shedding Levels<\/b>– This is individual to the horse and can be quite variable from one horse to another. A healthy pastured horse with a low egg shedding potential will tend to always have a low FEC, while a healthy pastured horse with a high egg shedding potential will tend to always have a high FEC, this can change based on a horse’s immunological status, but seems to be consistent. 20% of the horses shed 80% of the eggs in a given herd.<\/span><\/i> Determining egg shedding levels is not useful for young horses < 3yrs of age. <\/span><\/p>\n<\/li>\n<\/ol>\n

      Low Contaminators 0-200 EPG 50-70% of adult population<\/span><\/p>\n

      Moderate Contaminators 200-500 EPG 10-20% of adult population<\/span><\/p>\n

      High Contaminators >500 EPG 20-30% of adult population<\/span><\/p>\n