Equine Internal Parasites

1. Equine Internal Parasites

2. The Whole Picture

3. Benefits of Deworming Increased productivity Improved health Better immune status Increased breeding efficiency Reduced pasture contamination There are a number of direct and indirect gains received from deworming your horses, all of which can be influential to the profitability of your operation. It is often taken for granted the indirect effect parasite control programs have on the immune status of the animal, which may affect the susceptibility of horses to infectious diseases. The horse must receive effective internal parasite control for optimum response to good nutrition and a good vaccination program.There are a number of direct and indirect gains received from deworming your horses, all of which can be influential to the profitability of your operation. It is often taken for granted the indirect effect parasite control programs have on the immune status of the animal, which may affect the susceptibility of horses to infectious diseases.

4. Equine Parasite Control Why should we change our current program and customize treatment? Anthelmintic resistance has been documented in the US All horses and situations are different. Deworming control programs should be too. Many variables can increase or decrease your horses� risk for internal parasites No new equine anthelmintic products on the horizon Individualized program will control parasites and extend useful life span of current products

5. Why deworm? Equine parasites can damage many vital organs within the horse causing severe illness, lack of performance and poor appearance It is important to choose dewormers that protect against a variety of parasites as you can see they all affect different parts of a horse�s bodyEquine parasites can damage many vital organs within the horse causing severe illness, lack of performance and poor appearance It is important to choose dewormers that protect against a variety of parasites as you can see they all affect different parts of a horse�s body

6. Why Parasites are Dangerous: Take the time to go through the various parasites and the damage they can cause to a multitude of different vital organs.Take the time to go through the various parasites and the damage they can cause to a multitude of different vital organs.

7. Small strongyles (cyathostomes) Large strongyles (bloodworms) Roundworms (ascarids) Tapeworms Pinworms and bots In general, do not pose a significant health threat, but should be considered in deworming programs) Key Equine Parasites These 1st four are the most important parasites to focus on when developing a deworming schedule; large strongyles (or bloodworms), small strongyles (or cyathostomes) and large roundworms (or ascarids) and tapeworms These 1st four are the most important parasites to focus on when developing a deworming schedule; large strongyles (or bloodworms), small strongyles (or cyathostomes) and large roundworms (or ascarids) and tapeworms

8. The direct cyathostome life cycle is 6 to 14 weeks (see slide 4). L3 larvae can remain encysted in large intestine mucosa for months to years � a state of arrested or inhibited development (the hypobiotic cycle). When hypobiosis ends, L3 larvae develop into encysted L4 stage and emerge into intestinal lumen. Hypobiosis is more typical of previously exposed adult horses. The direct cycle is more typical of cyathostome-na�ve yearlings. The direct cyathostome life cycle is 6 to 14 weeks (see slide 4). L3 larvae can remain encysted in large intestine mucosa for months to years � a state of arrested or inhibited development (the hypobiotic cycle). When hypobiosis ends, L3 larvae develop into encysted L4 stage and emerge into intestinal lumen. Hypobiosis is more typical of previously exposed adult horses. The direct cycle is more typical of cyathostome-na�ve yearlings.

9. Small Strongyle Life Cycle The slide provides a detailed illustration of the small strongyle life cycle. Horses acquire small strongyle infection during grazing when the ingest cyathostomin L3 larvae (inset). The larvae invade the small intestinal mucosa where they become encysted, appearing as small nodules. The nodules are readily visible at necropsy, and can be as numerous as 50 or 60 per square centimeter. The inset shows a cross-section of an encapsulated larva. The L4 larvae emerge weeks or months later into the lumen of the large intestine. The L4 larvae mature into egg-laying adults, passing their eggs (inset) in the horse�s manure. The eggs hatch immature larvae, which crawl up from the soil onto pasture grass. When the horse ingests the larvae, the cycle repeats. Encysted cyathostome larvae can remain in a state of inhibited development lasting for months or even years before emerging as adult worms. However, the direct life cycle for small strongyles is generally short, 6-14 weeks.The slide provides a detailed illustration of the small strongyle life cycle. Horses acquire small strongyle infection during grazing when the ingest cyathostomin L3 larvae (inset). The larvae invade the small intestinal mucosa where they become encysted, appearing as small nodules. The nodules are readily visible at necropsy, and can be as numerous as 50 or 60 per square centimeter. The inset shows a cross-section of an encapsulated larva. The L4 larvae emerge weeks or months later into the lumen of the large intestine. The L4 larvae mature into egg-laying adults, passing their eggs (inset) in the horse�s manure. The eggs hatch immature larvae, which crawl up from the soil onto pasture grass. When the horse ingests the larvae, the cycle repeats. Encysted cyathostome larvae can remain in a state of inhibited development lasting for months or even years before emerging as adult worms. However, the direct life cycle for small strongyles is generally short, 6-14 weeks.

10. Small Strongyles Concerns: Encysted larval forms Cyst wall forms protective barrier Conventional dewormers are not effective #1 Concern�Larvae exiting cysts may cause: Colic Diarrhea Fever Death Large strongyles were once seen as more destructive than small. However, conventional wormers have significantly reduced the threat of large strongyles. Meanwhile, small strongyles occur at a much higher magnitude, posing a great risk to the horse. The larval form of the small strongyles form a protective cyst within the lining of the intestine. At the current time, there are only two deworming products effective against this stage of parasite: Moxidectin (QUEST�) �single dose; or Fenbendazole (Panacur� PowerPack�which equates to a 10x dose of Panacur� or Safeguard�). Larvae which exit the cyst will produce toxins which may lead to colic, diarrhea, fever and possible death in severe cases.Large strongyles were once seen as more destructive than small. However, conventional wormers have significantly reduced the threat of large strongyles. Meanwhile, small strongyles occur at a much higher magnitude, posing a great risk to the horse. The larval form of the small strongyles form a protective cyst within the lining of the intestine. At the current time, there are only two deworming products effective against this stage of parasite: Moxidectin (QUEST�) �single dose; or Fenbendazole (Panacur� PowerPack�which equates to a 10x dose of Panacur� or Safeguard�). Larvae which exit the cyst will produce toxins which may lead to colic, diarrhea, fever and possible death in severe cases.

11. Parasite Resistance Resistance develops over time, due to selection for a specific gene pool subset. Initially, this gene pool subset is a very small minority of the parasite population. This subset is less susceptible (resistant) to the effects of the dewormer compound.

12. Parasite Resistance Over an extended period of time, through repeated exposure to the dewormer product, the susceptible population is replaced by the resistant population. In time, the resistant parasites become the dominant population. The dewormer is only marginally or no longer effective. Over a long enough period of time and with enough dewormer exposures, the selection for the resistant population of parasites can and will occur with any product.

13. What Causes Dewormer Resistance?

14. Traditional vs. Strategic Parasite Control Traditional Focused on large strongyles Tapeworms ignored Small strongyles ignored Treatment intervals 4-7 wks Strategic Focus on small strongyles Deworming history (frequency and type) Analysis of currently used deworming products Periodic fecal examinations ID high, moderate & low shedders In the past, parasite control programs have been focused on large strongyles. Treatment intervals of 4-8 weeks have been necessary to attain acceptable levels of control with conventional equine dewormers (including ivermectin). The strategic approach considers a number of different factors. What is the age of the horse (foal vs. adult)? Has the type and frequency of deworming been adequate with regards to the period of egg reappearance? Wet, humid vs. dry geography/environment? What other health issues may be affecting the innate immunity of the horse? Periodic quantization/qualitative fecal exams can aid in customizing your parasite control program for your individual farm/premise. Your veterinarian should serve as your key resource when analyzing these factors and can also perform and interpret a quantitative fecal exam.In the past, parasite control programs have been focused on large strongyles. Treatment intervals of 4-8 weeks have been necessary to attain acceptable levels of control with conventional equine dewormers (including ivermectin). The strategic approach considers a number of different factors. What is the age of the horse (foal vs. adult)? Has the type and frequency of deworming been adequate with regards to the period of egg reappearance? Wet, humid vs. dry geography/environment? What other health issues may be affecting the innate immunity of the horse? Periodic quantization/qualitative fecal exams can aid in customizing your parasite control program for your individual farm/premise. Your veterinarian should serve as your key resource when analyzing these factors and can also perform and interpret a quantitative fecal exam.

15. Equine Parasite Risk Factors There are many potential risk factors to consider in setting up a deworming control program: Age of horse Geography Climate Stocking Densities Manure management Sanitation

16. Equine Parasite Control Risk factors continued: Pasture management Improper dosing�under dosing Parasite life cycle Donkeys on premise Refugia

17. How to Discover a Horse�s I.D.? (Individualized Deworming) Step 1 � Evaluate current product effectiveness Prior to deworming, do a FEC that gives a quantitative, eggs per gram (EPG) result Do a 2nd FEC 10-14 days after anthelmintic treatment to determine the fecal egg count reduction (FECR) FECR test should show at least 90% reduction in egg count to say resistance is not occurring for most de-wormers Less than 80% would suggest lower efficacy and would lead to recommendation of switching de-wormers

18. How to Discover a Horse�s I.D.? (Individualized Deworming) Step 2 - Do quantitative fecal analysis on all horses Or 10% of horses in a large herd Low shedders--less than 150-200 EPG 50% of horses (on average) Depending on geography & management Moderate shedders�200-500 EPG 20-40% of horses (on average) Depending upon geography and management) High shedders--greater than 500 EPG 10 - 20% of horses (on average) Depending on geography and management

19. Doing Fecal Egg Counts

20. How to Discover a Horse�s I.D.? (Individualized Deworming) Age of horses Local climate cycles Type of pasture (lush or over grazed), dry lot, mixture Horse density on property Management issues Individual stalls or paddocks Individual pastures Small group pastures Large group pastures

21. How to Discover a Horse�s I.D.? (Individualized Deworming) How horses are fed On the ground Off the ground Individually or in groups Manure removal Pastures rotated Problem parasites on property Use of horse New horses entering property or transporting

22. How to Discover a Horse�s I.D.? (Individualized Deworming) Low Risk Horse Middle aged animal Fed off the ground Low stocking density Pasture shared with cattle, sheep or goats. Not other horses Manure removed daily

23. How to Discover a Horse�s I.D.? (Individualized Deworming) Step 4 - Design Individual Deworming Program FECs of individual horses FECRT of products Risk assessment by veterinarian Take into account ERP (egg reappearance period) of various products

24. Deworming Guideline Examples

25. Equine Parasite Control To be successful: Decisions must be science & evidence based Veterinarian is key in evaluation and designing individualized and targeted deworming plan

26. Key Features Only active ingredient FDA approved to treat and control encysted strongyles in 1 dose Not an Ivermectin clone Controls small strongyle egg appearance for 84 days Unique palatable gel formulation � fast acting for ease of use QUEST� Plus Gel contains praziquantel for control of tapeworms Packaging 0.4 oz (11.6g) Sure-Dial� syringe Each syringe of QUEST � treats up to 1,150 lbs body weight Each syringe of QUEST � Plus treats up to 1,250 lbs body weight QUEST� GEL / QUEST � PLUS(moxidectin / moxidectin/praziquantel)

27. QUEST� GEL / QUEST � PLUS(moxidectin / moxidectin/praziquantel) Approved for removal and control of: Large strongyles Small strongyles Encysted cyathostomes Large roundworms / ascarids Pinworms Hairworms Large mouth stomach worms Stomach bots Tapeworms (A. perfoliata) � QUEST� Plus only

28. STRONGID� C / STRONGID� C2X (pyrantel tartrate) Packaging Doses per package for 1,000 lb horse STRONGID C2X 50 lb bag = 400 daily doses STRONGID C2X 10 lb pail = 80 daily doses STRONGID C 25 lb bucket = 100 daily doses Approved for the control of: Large strongyles � adults Small strongyles � adults and L4 larvae Roundworms / ascarids � adults and L4 larvae Pinworms � adults and L4 larvae

29. Summary:Discover a Horse�s True ID Individualized, targeted deworming control programs must be based on good science & associated risk factors. Veterinarian is a key partner in determining the best deworming program for individual horses & herds. Individualized deworming programs Designed to fit each horse�s life Unique set of conditions & needs Pfizer has all the products necessary for any type of program.

31. Slide 38 QUESTions?Slide 38 QUESTions?