Presentation on theme: "Integrated Parasite Management for Small Ruminants Slides contributed by Marguerite Frongillo, Steve Hart, Susan Schoenian, Mary Smith DVM and tatiana."— Presentation transcript:
Integrated Parasite Management for Small Ruminants Slides contributed by Marguerite Frongillo, Steve Hart, Susan Schoenian, Mary Smith DVM and tatiana Stanton
Know your weapons Effective management Effective drug use Effective surveillance
Integrated Parasite Management (IPM) Goal is not to create parasite-free animals. It is normal for sheep and goats to have parasites. Goal is to prevent clinical disease and production losses.
Parasite control begins with good management and common sense Good sanitation Feeders which prevent wastage and contamination. Clean water, free from fecal matter. Not overstocking pens and pastures. Isolation and deworming of new animals in an area where you can retrieve their manure easily.
Pasture Management to reduce barber pole worm problems Use clean or safe pastures – easy to say, difficult to implement for entire grazing cycle Use multispecies grazing Use alternative forages Make wise management decisions about pasture height, pasture rest, and pasture rotation
Use clean or safe pastures What is a truly safe pasture? New pasture Pasture that has been renovated with tillage A pasture that has not been grazed by sheep or goats for the past 6 to 12 months – however, worm population does start to drop sharply after 2 months. Pasture grazed solely by horses and/or cattle for the past 6 to 12 months. Pasture in which a hay, baleage or silage crop has been removed. Pasture that has been rotated with row crops. Burnt pasture
Dilute worm population by grazing multiple species Sheep and goats share the same internal parasites, but they are different from the parasites that generally affect cattle and horses. Cattle and horses vacuum sheep/goat pastures. Other benefits complimentary grazing habits.
Is this multispecies grazing? Is it going to be helpful?
Alternative forages Livestock that browse have fewer parasite problems (excepting deer worm). Livestock grazing tall-growing forages will have less parasite problems. 80% of parasites live in the first 2 inches of the vegetation. Grazing high-tannin forages may reduce the effects of parasitism.
Pure stands of chicory, birdsfoot trefoil, and Sericea lespedeza have been shown to reduce fecal egg counts and/or larval development. Birdsfoot Trefoil Forage Chicory Sericea Lespedeza
Hayfield Regrowth is a safe pasture alternative in late summer and fall
Pasture Height – 80% of the internal parasites found in bottom 2 inches of vegetation Not a big concern during first pass through your rotational pastures after winter. Big concern in later passes.
In a grazing system for small ruminants we are: Generally trying to move animals before the pasture is below 3 inches and get back in before pasture gets too mature
Too high and mature high lignin less nutritious and palatable for small ruminants trampling losses, etcetera
Problems with intensive rotational grazing and small ruminant parasites - In a rotational grazing system with the primary purpose of controlling worm populations, sheep/goats should not be returned to the same pasture for at least 45 to 60 days This conflicts with the use of intensive rotational grazing to increase the nutritional off- take from a pasture Due to increased stocking rates and rapid grazing intervals, management intensive grazing may increase internal parasite problems in sheep and goats as the grazing season progresses.
In summary If animals are left in a grazing paddock for longer than 5 to 10 days, depending on weather, may be exposed to infectious larvae Pasture rest periods to control internal parasites need to be longer than normal recommendations for either pasture health or nutritional value
Things to consider when using intensive rotational grazing Are there safe pastures that animals can be moved onto as grazing season progresses? Brush pastures Hayfield regrowth Pastures that your cattle or horses have been grazing Crop stubble or seeded annuals Can you disrupt the worm cycle by mowing the pasture extremely short, grazing other species, or harvesting a crop of hay or baleage before resuming grazing?
Rotational grazing in the spring appears to reduce the barnyard effect and delay the onset of summer parasite problems
Barnyard Effect Barnyards with grass or other good forage Lead to high concentration of manure and internal parasites in grazing material Can contribute greatly to herd contamination with internal parasites May have a barnyard effect in pastures that border barn and are not rotated
Manure pile right in yard – kids born late April – barn situated in very large pasture but kids and does tend to graze right by barn where manure concentration (and worm contamination) is highest. By late July kid loss to worms and coccidia
Please note that we are talking about herds that are rotating in the spring and summer and that by late July most of these also had high worm loads 23750 3575 2250
Goats free range on woodlands during the day and locked in very large compound 5 pm to 8 am compound seeded to pasture in 2004 herdsman noticed in Spring 2005 that kids did not go to woods with dams, instead stayed & grazed at compound kid loss by mid July to worms and coccidia.
Please note that we are talking about herds that are rotating in the spring and summer and that by late July most of these also had high worm loads 18875 3700 100
Central graining and watering areas can also have a barnyard effect
On these two farms, shelter and grain troughs move with the herd from pasture to pasture eliminating barnyard effect
Some options to help reduce barnyard effect – Can you implement any of them? make barnyard small enough that very little forage present lay down gravel, concrete, or herbicides close off access to barnyard during day and on full moon nights provide hay in barn at night when animals come in from pasture to cut down on night grazing in the barnyard replace barnyards with narrow lanes from pastures to barn leave animals in rotated pastures 24 hours a day with portable shelter, water and feeders
Zero grazing Sheep/goats raised in confinement or dry lot (with no grass) have fewer stomach worm problems. Sheep/goats put in confinement or dry lot do not usually get re-infected with stomach worms. Coccidiosis could be more of a problem in confinement.
One farms forage management strategy to control worms hay feeding 30 Boer X breeding does from mid Dec through April. Herd kids in April and adult does wormed May1st. rotational grazing of conventional pastures (6 acres) from May through July, goats stay on each area ~1 wk before rotating to next pasture – returned to each pasture in ~ 45 days. Horses follow 2 weeks after goats in most fields. Individual animals are wormed as needed. Entire herd wormed at end of July at weaning.
Management Strategy continued month-long grazing of two brush pastures Aug through Sept (3 acres). Individuals wormed as needed. In 2006, entire herd fasted and wormed with 2 wormers for deer worm in October – wormers used are ones that barberpole worm already shows resistance to in herd strip grazing of hay field regrowth from Oct until mid Dec (7 acres), animals moved to new strip every 5 to 9 days and never repeated on same strip. Individuals wormed as needed. Some years entire herd wormed Dec 15, some years entire herd wormed March 15 th, some years neither worming necessary and only a few individuals wormed
Nutritional Management Animals on a high plane of nutrition and in better body condition are better able to withstand worm burdens. Nutrition in early pregnancy (fat stores) can affect the immune response to internal parasites. Sheep receiving higher levels of protein prior to lambing have lower fecal egg counts.
Immune Response Good nutrition stimulates immune system Can select goats and sheep for low fecal egg counts Other diseases which depress immune system (e.g. coccidiosis, Johnes) can cause increased worm problems
Immune Response When goat/sheep are lactating, immune system is suppressed and does not fight parasites. Arrested larvae acquired during the fall all mature simultaneously in the spring during lactation. Rationale for deworming before kidding. Protein consumption at 130% of daily requirements reduced flush of egg laying at parturition in sheep
Genetic Management Try to select for resistant animals
Resistant Breeds Some sheep and goat breeds are more resistant to worms. Sheep Gulf Coast Native Hair sheep Barbados Blackbelly St. Croix Katahdin Dorper (?) Royal White (?) NOT Traditional wooled breeds Goats Possibly – Spanish/Brush Myotonic/Tennessee Pygmy Kiko (?) NOT Boer goats Dairy goats Angora goats Savanna????
Resistant Individuals Parasite resistance varies between individual animals of the same breed type. 20-30 percent of flock shed most of the parasite eggs. Focusing deworming on susceptible animals will significantly reduce pasture contamination. BUT - Lactation and weaning are examples of environmental effects that render an animal more worm-susceptible. Culling worm-susceptible animals that have no environmental excuse for being wormy should increase flock resistance and reduce pasture contamination.
Drugs A valuable, limited resource that must be managed properly.
Three drug families 1)Benzimidazoles Chemical name ends in '..dazole Fenbendazole, Albendazole, Oxybendazole 2)Nicotinics Levamisole, Morantel, Pyrantel 3)Macrolides Avermectins Ivermectin, Doramectin Moxidectin
Benzimidazoles – white drenches Fenbendazole – SafeGuard® or Panacur® Albendazole – Valbazen® Oxyfendazole – Synantic ® Broad spectrum Wide margin of safety Effective against tapeworms Valbazen Effective against adult liver flukes. Should not be administered to pregnant animals.
Nicotinics Levamisole - (clear drench). Tramisol ®, Levasole®, Prohibit® Morantel– Rumatel®, Positive Goat Pellet Pyrantel - Strongid® Rumatel Oral feed additive Only effective against adult worms Pyrantel Only effective against adult worms Levamisole Broad spectrum Effective against arrested larvae Narrower margin of safety, especially injectable product
Macrolides Ivermectin –Ivomec®, Zimecterin ®, Eprinex ®, Promectin® Doramectin - Dectomax ® Moxidectin – Cydectin ®, Quest ® Broad spectrum Wide margin of safety Effective against (biting) external parasites Moxidectin Newest drug Has Persistent activity
Extra-label drug use Only Fenbendazole (SafeGuard®) and Morantel (Rumatel®) are FDA- approved for goats. Only Albendazole (Valbazen ®), Ivomec ® drench, and Levamisole (drench and bolus) are FDA- approved for sheep. Use of a product that is different than its label constitutes extra- label drug use and requires a veterinary prescription in context of valid veterinarian-patient- client relationship. Should use exaggerated withdrawals when using drugs extra label (keep records). Check with http://www.farad.org/
Non-chemical dewormers – not yet! Botanical dewormers - herbs Diatomaceous earth (DE) No scientific studies have shown DE or other non- chemical treatments to reduce fecal egg counts Many natural dewormers would have to be given at toxic levels in order to be effective Garlic juice has shown promise? Other Tannins, fungus Copper boluses (goats) vaccine
Epazote Study 1) Oil of Chenopodium administered in gel capsules at a rate of 0.15ml/kg body weight is ineffective in reducing the number or viability of internal parasite eggs in NY sheep and goats. Higher dose toxic to host animal. A commercial organic worm discourager and a soluble soap, Basic H, were equally ineffective.
Lungworms Indirect or direct life cycle Severe infestations cause coughing, fluid in lungs, pneumonia Transmitted in feces Take fecal sample direct from animal (otherwise can confuse with soil nematodes) Same control program as stomach and intestinal worms.
Tapeworms Life Cycle Worms live in small intestines. Eggs pass out through feces. The egg is eaten by a pasture mite. The egg hatches. The mite is eaten by the sheep or goat. Light loads of tapeworms tend not to be a problem, but severe infestations can cause problems. Pasture mite
Coccidia Eimera sp. (species-specific) Single-cell protozoa that damage lining of small intestines. Can cause bloody diarrhea that may be smeared with mucous Damage can be permanent! Prevent with good sanitation and proper stocking
Coccidiosis Suspect when animals get diarrhea after 3 weeks of age mucky butt in lambs many Eimeria species, host specific, variable pathogenicity immunity to each species of coccidia develops with exposure warmth and moisture permit sporulation From Egg to infectious 1-2 days but easily survive 2-3 mo and can survive 1 year in optimum conditions Killed by direct sunlight and low humidity (<25%)
Life Cycle of Eimeria spp.
Severe coccidiosis in goats/sheep causes many small white foci in the intestinal wall – absorption impaired
Fecal exams for coccidia may have 10,000 or 100,000 per gram without disease Egg count drops only for a short time after treatment then rebounds none in older animal? You didnt look!
Coccidiosis raise dairy kids away from adults If possible, separate lambs and kids by age, ideally only a 2 weeks spread in age in a group milk is protective, weaning precipitates diarrhea coccidiostats in the milk and starter feed – decoquinate, monensin, lasalocid
Can use coccidiostats as additives in the feed, salt or water to help prevent: Especially in pregnant females starting 1 month before parturition until weaning of their young. Continue in young animals after weaning. Lasalocid (Bovatec®) 1,3 Monensin (Rumensin®) 2,3 Dequinate (Deccox®) 1,2 Amprolium (Corid®) in water 1 - FDA-approved for sheep 2 - FDA-approved for goats 3 - TOXIC to EQUINES!!!!!!
Sanitation – clean and dry keep kids and lambs out of feeders !
Treatment of coccidiosis oral sulfonamides –Sulmet, Albon, etc. amprolium 25-50 mg/kg per day for 5 days = 1 ml Corid 9.6% per 8 pounds can add to milk or directly drench treatment temporarily decreases shedding but does not eradicate parasite – rebound in oocyst count adequate selenium for immunity
Meningeal worm (deer, brain worm) Parelaphostrongylus tenuis Parasite of White Tail Deer Small ruminants are an abnormal host (sheep, goats, llama, alpaca) Parasite has indirect life cycle – snails and slugs needed for infection
Larva travel from intestinal tract to spinal cord to brain, causing Nerve damage (can include lameness, gait abnormality, itching) can be as extreme as paralysis or even DEATH Animals maintain appetite
Differential diagnoses CAE, OPP fracture, vertebral body abscess copper deficiency tail docking infection foot rot, white muscle disease listeriosis Polio- encephalomalacia brain abscess rabies scrapie
Treatment of P. tenuis in aberrant hosts no controlled studies escalation of drug dosages ivermectin 0.2 to 1.0 mg/kg for 1-5 d fenbendazole 10 to 50 mg/kg for 1-5 d usually both simultaneously anti-inflammatories important corticosteroids if not pregnant: dexamethasone 0.1 mg/kg s.i.d. for 3-5 d flunixin 1 mg/kg s.i.d. or b.i.d. for 3 d
Prevention of exposure do not pasture at edge of woods especially during wet season avoid low-lying poorly drained fields except under very dry conditions fence off deer watering spots use fields deer prefer for hay, not grazing guardian dog may help take advantage of hunting season!
Prophylaxis in aberrant host for camelids, probably not for sheep and goats (Haemonchus resistance) injectable ivermectin q 4-6 wk pour-ons? (not sheep or goats) newer avermectins with longer duration? fenbendazole daily pyrantel not effective
Liver flukes Some farms in NE US have acute or chronic liver fluke populations Requires open water, snails (wet conditions) Can kill adult liver flukes with Albendazole (Valbazen®) or Ivomec® Plus)
Fasciola hepatica common liver fluke cycle includes fresh water snails acute peritonitis (during migration) Often causes chronic problems afterwards hypoproteinemia, anemia (blood leaks into bile)
Fascioloides magna American deer fluke natural parasite of deer and elk sheep and goats abnormal hosts larval stages continue to migrate through liver - sheep and goats dont excrete eggs ACUTE disease - usually fatal within 6 months
liver of goat killed by fluke
Treatment of liver flukes fence off wet areas albendazole – 15 to 20 mg/kg, adult flukes clorsulon orally - adult Fasciola 3.5 mg/kg sheep, 7 mg/kg goats clorsulon orally – 8 wk Fasciola 7 mg/kg sheep, 15 mg/kg goats clorsulon for Fascioloides – 21 mg/kg