1 / 40

PARASITES AND DEWORMING YOUR HORSES Control vs. Eradication

PARASITES AND DEWORMING YOUR HORSES Control vs. Eradication. Karen Kalck, DVM, DACVIM Equine Medicine University of Tennessee Veterinary Medical Center. PLAN. Introduction Signs of parasitism Types of parasites Dewormers Diagnostics Designing a deworming program. QUESTIONS.

abeni
Download Presentation

PARASITES AND DEWORMING YOUR HORSES Control vs. Eradication

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PARASITES AND DEWORMING YOUR HORSES Control vs. Eradication Karen Kalck, DVM, DACVIM Equine Medicine University of Tennessee Veterinary Medical Center

  2. PLAN • Introduction • Signs of parasitism • Types of parasites • Dewormers • Diagnostics • Designing a deworming program

  3. QUESTIONS • Raise your hand if you deworm your horse(s) every 2-3 months? • Every 4-6 months? • Once per year? • Whenever you remember to?

  4. COMMONLY ASKED QUESTIONS • What type of wormer should I use? • When should I worm my horse? • Should I rotate my wormers each time? • Should I use the same wormer all year long? • How often should I worm and when? • What are fecal egg counts and do I need to have these done? • How effective are feed through wormers? • My horse is rubbing it's tail, is this because of worms?

  5. COMMON PRACTICES • Deworm 4 times per year • Deworm 2 times per year, once after the first frost and once after the first hay cutting • Deworm all year with the same dewormer • Rotate your dewormer each time • Only deworm if your horse is thin and not putting on weight

  6. PARASITES vs. BACTERIA • No replication of numbers within the host • Life cycle • No immunity to parasites

  7. SIGNS OF PARASITISM • None • Lethargy • Loss of appetite • Dull, rough haircoat • Tail rubbing and hair loss • Loss of condition/weight • Slow growth in young horses • Pot belly • Coughing, nasal discharge • Diarrhea • Colic • Death

  8. TYPES OF PARASITES • Large strongyles • Small strongyles • Roundworms • Tapeworms • Pinworms • Lungworms • Bots • Strongyloides

  9. Large Strongyles Pinworms Roundworms (Ascarids) Small Strongyles Tapeworm

  10. LIFECYCLE Grazing  eggs/larvae swallowed • Eggs • Manure of infected horse • Ground Larvae migrate out of intestines, into other tissues, and then return to intestine • Larvae • Immature worms • Stomach/intestines • Adults • Mature worms passed in feces

  11. STRONGYLES • Also known as bloodworms, red worms • Can cause anemia • Damage colon • Mesenteric arteritis (large only)

  12. LARGE STRONGYLES

  13. SMALL STRONGYLES

  14. ROUNDWORMS • Ascarids • Young horses (<2 years) • Large  up to 15 inches in length! • Do not suck blood • Small intestinal obstruction • Can migrate through the lung, causing damage and pneumonia

  15. TAPEWORMS • Affect the last part of the small intestine and cecum • Can cause ileal impactions • Eggs often not found in the feces

  16. PINWORMS • Females deposit eggs around anus in a “cement-like” mixture • This dries and cracks, causing irritation • “Rat-tail” appearance

  17. BOTS • Not worms, but fly larvae • Female flies lay eggs on horse legs • Horse ingests eggs • Larvae hatch and migrate to the stomach

  18. DIAGNOSTICS - Collection • Collect fresh feces in ziplock bag • Label with horse name and date • Send/take to veterinary laboratory • Herd  Collect individual samples on same day

  19. DIAGNOSTICS • Fecal float • Good screening test for all parasites • Does not quantify • Fecal egg count (FEC) • Not to be used for screening • Will quantify numbers of eggs per gram of feces • Only for strongyles and roundworms

  20. CONTROL VS. ERADICATION • Must encourage anthelmintic-sensitive worms in population • Do not want to become outnumbered by resistant worms

  21. GOAL = CONTROL • Keep FEC low • Reduce transmission • Reduce the development of drug resistance • Have happy, healthy horses • Kill adult parasites  NO!!!

  22. Pyrantel pamoate • Strongid T • Rotation 2 DEWORMERS • Ivermectin • Zimectrin • Equimax • Eqvalan • Ivercare • Rotation 1 • Praziquantel • Quest plus • Zimectrin gold • Equimax • Moxidectin • Quest • Fenbendazole • Panacur • Safe-guard • Oxibendazole • Anthelcide

  23. DEWORMERS Tape - Round - Pin - Strongyles Bots worms worms worms Ivermectin / X X X Moxidectin Pyrantel X X X pamoate Oxibendazole X X X Praziquantel X Fenbendazole X X X

  24. DAILY DEWORMER • Pyrantel tartrate (Strongid C) • Does not resolve existing infections • Not effective against tapeworms or bots • Resistance! • Only appropriate in very specific situations

  25. DESIGNING A DEWORMING PROGRAM • Do not deworm all horses every 8 weeks! • High levels of drug resistance • Biology of parasites has changed • Different worm demographics from horse to horse

  26. DESIGNING A DEWORMING PROGRAM • New recommendations – strategic deworming • Treat some horses more and others less • Involves FEC • Advantages • Fewer deworming treatments • Less drug resistance • Better worm control

  27. POSSIBLE DEWORMING PLAN • First treatment in September • Last treatment in March • No further deworming until fall unless there is a very cool, wet summer

  28. POSSIBLE DEWORMING PLAN • Determine which anthelmintics are working in the herd • September  Egg counts on all horses • Categorize horses’ contaminative potential • <200 epg = low contaminators • 200- 500 epg = moderate contaminators • > 500 = high contaminators

  29. HYPOTHETICAL DISTRIBUTION OF STRONGYLE EGG COUNTS IN A HORSE HERD LOW (50%) MODERATE (30%) HIGH (20%) NUMBER OF HORSES FECAL EGG COUNT (per gram of feces)

  30. LOW CONTAMINATORS (< 200 epg) • September  Treat with Ivermectin-Praziquantel • March  Treat with Moxidectin-Praziquantel OR

  31. MODERATE CONTAMINATORS (200-500 epg) • September  Treat with Ivermectin-Praziquantel • November  Treat with oxibendazole and/or pyrantel (together) • March  Treat with Moxidectin-Praziquantel OR +

  32. HIGH CONTAMINATORS (> 500 epg) • September  Treat with Ivermectin-Praziquantel • November  Treat with oxibendazole and/or pyrantel (together) • December  Treat with Moxidectin • March  Treat with Moxidectin-Praziquantel OR +

  33. DEWORMING:Strategic vs. Every 2 months Number of Classification # of horses Subtotal Grand total doses/year Low 10 2 20 Moderate 6 3 18 54 High 4 4 16 Every 2 mos. 20 6 120 120

  34. DEWORMING IN FOALS/WEANLINGS • Start at 2 months of age • Deworm monthly • Alternate pyrantel and ivermectin • At 8 and 12 months give a product with praziquantel as well OR

  35. ENVIRONMENTAL CONTROL • Moisture • Strongyle transmission occurs almost exclusively on pasture • Stall and dry-lots are negligible • Season (in TN) • Summer  lowest pasture infectivity • Winter  cool enough to promote larval persistence

  36. ENVIRONMENTAL CONTROL • Manure management • Pasture rotation and management • Avoid over-stocking • Group horses by age • Feeders

  37. EQUINE WELLNESS PROGRAMUT Equine Hospital and Field Services • Comprehensive health care program for horses • Pleasure horse • Performance horse • Yearly health care needs in one package • Packages are a 20% discount from individual pricing • Eligible for additional discounts and benefits • Sign-up beginning March 12th, 2011!

  38. HORSE OWNERS CONFERENCE • March 12th, 2011 @ 8 am • At UT – Hollingsworth auditorium • Topics • Wellness program • Small pasture management • Fescue toxicosis • Foot care and diseases • Use of common medications in horses • Lameness examinations • $28/person ($15 for additional family members) • www.vet.utk.edu/continuing _ed

  39. UTVMC OPEN HOUSE • Saturday April 16, 2011 from 9 am – 4 pm • Educational day for families • Teddy Bear Clinic • Canine Parade of Breeds • Equine Parade of Breeds – including Amigo! • Farm Animals • Wildlife and Exotic Animals • Physical Therapy for Animals • www.vet.utk.edu/openhouse

  40. QUESTIONS?? • Thank you to Dr. Sharon Patton for providing information and pictures

More Related