Parasite Manageme

nt

Beth Johnson, DVMKentucky Department of Agriculture

Office of State Veterinarian502-573-0282 (office) 502-545-6373

(cell)bethc.johnson@ky.gov

Common Parasites of Small Ruminants

• Internal parasiteso “HOT” Complex• Haemonchus• Ostertagia• Trichostrongylus

o Tapewormso Coccidiosiso Paralephastrongylus – “Meningeal Worm”

Common Parasites of Small Ruminants, contd.

• External ParasitesoLiceoMitesoTicksoFlies

General Lifecyle of Nematodes

• Eggs are passed in feces.• L1 and L2 stage develop in fecal pellet• L3 climbs onto grass blades with water droplet• Animal consumes blade of grass with L3• L4 and L5 develop within host• Adult emerges and produces egg within the host

General Life Cycle of P. tenuis

(Meningeal Worm)

General Life Cycle of Eimeria

(Coccidiosis)

Signs of Parasitism• Loose Stools• Unthrifty/Decreased performance(milk

production, wool, growth)• Bottle Jaw• Anemia• Wool/Hair loss

Treatment Options

Strategic Dewormingo Famacha score (1-5) Screening for H. contortuso Parturitiono Prior to breeding (Flushing)o Young Kids/lambso Rotate pastures with animals not susceptible to small ruminant parasiteso Fast animals for 12-24 hours prior to deworming, then

maintain on dry lot for 8-12 hours afterwards

Resistant Parasites• How does this happen?• Refugia – do not deworm all animals in

flock/herd at one time.• How to deal with resistant parasites?• Anthelmintic Use• Select animals for parasite resistance

Anthelmintic Types/Uses

• Moxidectin• Ivermectin• “White” Dewormers

o Fenbendazoleo Valbazen (do not use in pregnant animals or young

crias) • Levamisole• Copper Sulfate• Coccidia Treatments

• Sulfadimethoxine 12.5%• Amprolium• Ponazuril

Environment Control• Avoid Overcrowding!!!!!

• Pasture Managemento Goats: “Keep their heads up!”o Sheep: Rotational grazing, prevent overgrazingo Keep grass taller than 4 incheso Confinement: Keep area cleano Water: Keep clean fresh water available at all times

Use of Alternative Forages and other “Natural” Anthelmintics

• Sericea lespedeza, chicory, birdsfoot trefoil• Diatomaceous earth• Botanicals

o Pumpkin Seedso Papaya Seedso Garlico No controlled studies on these or their effectiveness as an

anthelmintic

• Copper oxide wire particle boluses (2.5gram Boluses)