Reducing parasite resistance on equine operations using a comprehensive, whole-farm approach

Reducing parasite resistance on equine operations using a comprehensive, whole-farm approach

Summary

Indiscriminate use of dewormers has caused an alarming increase in cyathostomes. Cases of resistant equine parasites are being reported worldwide. Many horse owners contribute to the development of resistant parasites by deworming horses every eight weeks and may be using products that are totally ineffective. Adoption of new deworming practices can decrease the proliferation of resistant parasites and maintain the effectiveness of the products that are available.

In order to empower horse owners to make changes in their deworming program, it is important to provide clientele with the knowledge and skills necessary to be confident they are making good management decisions. The project team,  composed of Extension Educators, veterinarians, farm owners, and the project consultant met to determine curriculum content  for a comprehensive parasite management short course, Managing Equine Parasites Using a Whole Farm Approach.  The short course was offered at three locations in Pennsylvania. Topics included: parasite types; biology and behavior; the science of resistance; the importance of establishing a “non-resistant” refuge; conducting and using fecal egg counts; classes of dewormers; the danger of short interval deworming; pasture management and composting as a tool to reduce parasite burdens; and the effects of temperature, rainfall, pasture rotation and manure handling practices on parasite development and infection. 165 farm managers and veterinarians participated in the short course.

The research portion of the project was designed to help farm managers develop farm specific strategic deworming practices.   In order to serve as farm partners, the farm managers were required to complete the short course.  The farm partners met at predetermined sites and conducted fecal egg counts on all horses on the farm in order to monitor egg shedding and identify “shedders”. Product efficacy was determined by conducting pre and post deworming egg using horses that were moderate to high shedders. Since lack of monitoring equipment is an obstacle to conducting egg counts, participants utilized microscopes and supplies strategically placed in Extension offices. Trained Extension staff provided assistance and ensured that protocol was followed. Fifty-seven horse farms representing 462 horses, in 19 PA counties enrolled as partners in the research project.

• Research Project Protocol
• Evaluation of the Research Portion of the Project
• fecal Egg Count Monitoring Schedule

Objectives/Performance Targets

• 260 of 300 participants in the short course, Managing Equine Parasites using a Whole Farm Approach, will implement at least two new practices to reduce parasite burdens on pastures (remove manure from pastures, improve pasture quality to reduce  grazing in manure deposition areas, rotate pastures after  deworming, deworm new individuals, compost manure before applying to pastures,  use fecal egg counts to strategically deworm “shedders”).

In 2015 – 164 farmers completed the short course, 100% adopted at least one practice to reduce parasite burdens, 92% adopted two or more practices.

• 80 farm managers that completed the course will use established protocol to conduct pre and post fecal egg counts , supplying data from 640 horses (average – 8 per farm) and will:

• document egg shedding in horses enrolled in the project.

• identify and eliminate the use of products that show resistance on their farms

• identify and strategically deworm the “shedders” on their farm

• eliminate 3 dewormings of all non-shedding  horses, resulting in an economic savings of $27 per horse annually.

In 2015, fifty-seven horse farms representing 462 horses, in 19 PA counties enrolled as partners in the research project.

After participating in the fecal egg count monitoring project:

100% stated that they were able to identify the high shedders on their farm

95% were able to identify the horses that had good immunity against small strongyles.

95% were able to determine the effectiveness of the dewormers they used on their farms

81% were able to reduce the use of dewormers

95%  stated that the project reduced their fear of parasites which often led to over use of dewormers

100% stated that the project increased their confidence in surveillance based deworming practices

100% stated they planned to conduct fecal egg counts on new horses

68% took steps to improve pastures to reduce grazing near manured areas

45% removed manure from pastures.

79% eliminated harrowing pastures or restricted harrowing to late fall

Accomplishments/Milestones

2014

• Develop fecal egg count monitoring protocol. Completed – March 2014

• Identify monitoring sites and project assistants. Completed – March 2014

• Develop and distribute project awareness and promotional material to PA equine veterinarians.

Completed- September to December 2014

• Develop curriculum, necessary data collection forms and training, marketing and evaluation materials. Completed – October to December 2014

• Market the program by placing ads in equine journals and distributing brochure and flyers.

Completed – December 2014

2015

• 300 farm managers will attend one of 6 short courses and will learn about parasite life cycles, resistance development, and the effects of temperature, rainfall, pasture rotation and  manure composting on parasite  infection.   Another 300 will attend stand-alone workshops on parasite biology and management. In 2015, four short courses were scheduled in March and April; one was cancelled due to winter storms.  A program for veterinarians was held in March 2015. Two stand – alone workshops were held in March and August, 2014.  In addition four youth parasite management programs were held for 4-H equine members.
• Identify farm managers for inclusion in the fecal egg count monitoring project – Completed – March and April 2015

• Present parasite management workshops at the Horse World Expo- Completed – March 2015

• Offer training for project assistants and participating farm managers  at the monitoring sites –Completed – January 2015.

• Farm managers enrolled in the project conduct fecal egg counts using established protocol and record data. Completed – March through October 2015

• Team and the farm veterinarian provide individual assistance with deworming strategies, and product selection and evaluation. Completed – March through November 2015

• Team conducts 6 individual workshops on parasite biology and management, properly composting manure and improving pastures to reduce parasite exposure. Held 3 pasture management classes, one manure management workshops, and 2 workshops on parasite management .  Completed – March through September 2015.

• Two additional short courses are offered in November. Not hold. Decided to offer 4 in early spring 2016 so that short course would directly precede the monitoring research part of the project.

2016

January through November

• Farm managers continue to document pre and post deworming  parasite levels in their horses

• Team continues to provide individual assistance for farm managers

• Four individual workshops on parasite management, properly composting manure and improving pastures to reduce grazing pressure in manured areas are offered.

• Participants in the short courses are surveyed to document practices that they adopted to reduce parasite exposure and proliferation of resistant parasites

2017

January and February

• Farm Managers participating in the fecal egg count monitoring project will complete an evaluation to document the impact that the project had on the reduction in number of  dewormings in non-shedding horses.  Participants will also report any products that failed to reduce egg shedding to acceptable levels indicating on-farm resistance to that product.

March through August

• Project team analyzes data on parasite level and product efficacy on PA farms and makes the information available to horse owners and veterinarians through presentation and by preparing peer reviewed abstracts and fact sheets and placing articles in equine journals and magazines.

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Impacts and Contributions/Outcomes

The support for this project from our peers, veterinarians and equine clientele has been overwhelming.  In fact, Dr. Martin Nielsen of the Gluck Institute in Kentucky was quoted in a national equine magazine as stating that this project could be a model for the rest of the nation.  Support from the equine industry and our farm partners has been equally impressive.  Because of the large amount of time required of our farm partners in collecting manure from all the farm horses, driving to the site and preparing and counting eggs in each sample, we assumed that only 75% of the farm managers would complete the project.  Only 2 farms withdrew from the project.  In both cases the farm was sold. The goal of the project was ultimately to change behavior – to move farm owners from deworming all horses every 8 weeks to utilizing fecal egg count numbers as a basis for deworming decisions. We found that there was a much larger impact and confidence in the data when it was obtained by the farm owner rather than another source. This confidence allowed horse owners to modify their behavior and reduce deworming of horses that were low shedders.

Farm owners participating in the project were able to determine the high shedders on their farm as well as the horses that had high levels of immunity and rarely required deworming.  Many farm managers were able to identify product resistance on the farms.  In fact one farm that relied heavily on pyrantel, often  using it as a daily dewormer had extremely high post deworming egg counts with many horses having higher fecal egg count numbers after deworming with the product. Results of the fecal egg reduction tests and the per cent of PA farms that harbor resistant parasites is still being evaluated.

One very interesting farm imported horses from a farm in the Midwest that did not routinely use deworming products.  When fecal egg count reduction tests were performed after using pyrantel, the parasites in the mid-west horses that had not been exposed to pyrantel were effectively eliminated after deworming.  The farm horses that had been routinely dewormed with pyrantel had resistant parasites.

A post project evaluation revealed the following results:

100% were able to identify the high shedders on their farm

95% were able to identify the horses that had good immunity against small strongyles.

95% were able to determine the effectiveness of the dewormers they used on their farms

81% were able to reduce the use of dewormers

95% stated that the project reduced their fear of parasites which often led to over use of dewormers

100% stated that the project increased their confidence in surveillance based deworming practices

100% stated they planned to conduct fecal egg counts on new horses

68% took steps to improve pastures to reduce grazing near manured areas

45% removed manure from pastures.

79% eliminated harrowing pastures or restricted harrowing to late fall

• Evaluation of the short course
• Evaluation of Fecal Egg Count Farm Partner Project
• Parasite Monitoring Project Photo
• Short Course Evaluation – Northampton County

Collaborators: