4/6/2011

1

SUSAN SCHOENIANSheep & Goat Specialist

Western Maryland Research & Education CenterUniversity of Maryland Extension

sschoen@umd.edu - www.sheepandgoat.com

CCCCRITICALRITICALRITICALRITICAL THINKINGTHINKINGTHINKINGTHINKING ININININ ANIMALANIMALANIMALANIMAL SCIENCESCIENCESCIENCESCIENCESpecies: small ruminants

Topic: parasites

WWWWESTERNESTERNESTERNESTERNMMMMARYLANDARYLANDARYLANDARYLAND RRRRESEARCHESEARCHESEARCHESEARCH & E& E& E& EDUCATIONDUCATIONDUCATIONDUCATION CCCCENTERENTERENTERENTER

� Keedysville Washington County

� 491 acres

� Three units� University of Maryland

Extension1. Administrative home for

West region

2. Extension specialists

3. Ag experiment station

4/6/2011

2

WWWWESTERNESTERNESTERNESTERNMMMMARYLANDARYLANDARYLANDARYLAND RRRRESEARCHESEARCHESEARCHESEARCH & E& E& E& EDUCATIONDUCATIONDUCATIONDUCATION CCCCENTERENTERENTERENTER

ResearchResearchResearchResearch Education (Extension)Education (Extension)Education (Extension)Education (Extension)

� Agronomy� Forages� Fruit� Horticulture� Small ruminants� Viticulture/enology

� Ag marketing

� Farm management

� Grapes and viticulture

� Forestry/natural resources

� Nutrient management

� Small ruminants

WWWWESTERNESTERNESTERNESTERNMMMMARYLANDARYLANDARYLANDARYLAND PPPPASTUREASTUREASTUREASTURE----BBBBASEDASEDASEDASED

MMMMEATEATEATEAT GGGGOATOATOATOAT PPPPERFORMANCEERFORMANCEERFORMANCEERFORMANCE TTTTESTESTESTEST

� Established in 2006 to evaluate the performance of meat goats consuming a pasture-only diet with natural exposure to gastro-intestinal parasites.

� Up to 70 weanling male meat goats are tested per year.

� While on test, goats are evaluated for growth, parasite resistance and parasite resilience, and carcass merit.

Early June – early October

4/6/2011

3

� Monogastric� Simple stomach� Pigs and poultry (and people)

� Ruminant� Cud-chewing � 4 compartment stomach.

- Cows, sheep, and goats� Pseudo-ruminant

(3 compartment stomach)-Alpacas and llamas

� Hind-gut fermenter� Fermentation occurs in the caecum and/or

large intestine� Horses and rabbits

CCCCLASSIFICATIONLASSIFICATIONLASSIFICATIONLASSIFICATION OFOFOFOF FARMFARMFARMFARM ANIMALSANIMALSANIMALSANIMALSBy their digestive systems

�Sheep

�Goats

� Cervids (deer)

� Camelids (alpacas and llamas)

SSSSMALLMALLMALLMALL RUMINANTSRUMINANTSRUMINANTSRUMINANTS

4/6/2011

4

SSSSHEEPHEEPHEEPHEEP ANDANDANDAND GOATGOATGOATGOAT PRODUCTIONPRODUCTIONPRODUCTIONPRODUCTION

� Meat� Lamb/mutton� Chevon/cabrito

� Fiber� Wool� Mohair� Cashmere

� Dairy� Milk� Cheese� Other

� Landscape management� Goats – shrubs, trees, browse� Sheep – weeds, grass

� Bio-medical/tech� Research models� Blood� Pharmaceutical production

SSSSHEEPHEEPHEEPHEEP ANDANDANDAND GOATGOATGOATGOAT PRODUCTIONPRODUCTIONPRODUCTIONPRODUCTION

� World� 1.93 billion sheep and goats

� China, Australia, India� 6 percent of world meat consumption� 3 percent of world fiber production� 3.4 percent of world milk production

� United States� 8.7 million sheep and goats

� Texas, California, intermountain states� Less than 1% of livestock receipts in U.S.� Per capita consumption of lamb is less

than 1 lb. per person (goat meat less).

4/6/2011

5

SSSSHEEPHEEPHEEPHEEP ANDANDANDAND GOATGOATGOATGOAT PRODUCTIONPRODUCTIONPRODUCTIONPRODUCTION ININININ MMMMARYLANDARYLANDARYLANDARYLAND

� 23,000 sheep� Maryland Sheep & Wool Festival� Maryland Wool Pool

� 14,900 goats� 2,400 dairy goats

� < 6 certified goats/sheep dairies

� 12,500 meat/other goats

� Counties that raise the most sheep/goats are Frederick, Carroll, Garrett, Baltimore

� While there are some commercial and larger farms, most are lifestyle farms.

� Average producer has less than 30 animals.

PPPPARASITESARASITESARASITESARASITES –––– WHATWHATWHATWHAT AREAREAREARE THEYTHEYTHEYTHEY????

� An animal or plant that lives in or on a host (another animal or plant); it obtains nourishment from the host without benefiting or killing the host.

� A (generally undesirable) living organism that exists by stealing the resources produced/collected by another living organism.

� Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the host.

4/6/2011

6

TTTTWOWOWOWO KINDSKINDSKINDSKINDS OFOFOFOF PARASITESPARASITESPARASITESPARASITES

External (External (External (External (ectoectoectoecto)))) Internal (Internal (Internal (Internal (endoendoendoendo))))

EEEEXTERNALXTERNALXTERNALXTERNAL ((((ECTOECTOECTOECTO) ) ) ) PARASITESPARASITESPARASITESPARASITES

� Ticks� Deer tick – lyme disease � Ked - sheep tick

� Biting and sucking lice

� Mites

� Fleas

� Flies� Nose bots� Fly strike (maggots)

� Diseases with insect vectors� Bluetongue virus� Cache valley virus

stillbirths and congenital abnormalities

4/6/2011

7

SSSSIGNSIGNSIGNSIGNS OFOFOFOF EXTERNALEXTERNALEXTERNALEXTERNAL PARASITISMPARASITISMPARASITISMPARASITISM

� Wool or hair loss� Rough hair coat� Itching� Rubbing� Scratching� Skin discoloration� Skin rash� Tail wagging� Distress� Foul smell (wound)� Visible signs of maggots� Snotty nose� Hold nose close to the ground� Weight loss

TTTTREATMENTREATMENTREATMENTREATMENT OFOFOFOF EXTERNALEXTERNALEXTERNALEXTERNAL PARASITESPARASITESPARASITESPARASITES

� Insecticides

� Pour-on� Sprinkle� Spray� Dust�Dip

(old-time, other countries)

� Some anthelmintics

� Macrocylic lactones onlyIvermectin, doramectin, moxidectin

� Ivermectin is usually drug the of choice

� Organic treatments

4/6/2011

8

FFFFOUROUROUROUR KINDSKINDSKINDSKINDS OFOFOFOF INTERNALINTERNALINTERNALINTERNAL PARASITESPARASITESPARASITESPARASITES

Nematodes (roundworms)

Protozoa

Trematodes (flukes)

Cestodes (tapeworms)

NNNNEMATODESEMATODESEMATODESEMATODES ((((ROUNDWORMSROUNDWORMSROUNDWORMSROUNDWORMS))))

Gastro-intestinal worms� Bunostomum sp.

Hookworm� Cooperia sp.

Small intestinal worm� Haemonchus contortus

Barber pole worm� Nematodirus sp.

Threadneck worm� Ostertagia sp. (Teladorsagia)

Medium or brown stomach worm� Oesophagostomum

Nodular worm� Trichostrongylus sp.

Bankrupt worm, hair worm� Trichuris ovis

Whipworm

� LungwormsDictyocaulus filariaMuellerius capillaris

� Meningeal wormDeer / brain wormParelaphostrongylus tenuis

4/6/2011

9

RRRROUNDWORMSOUNDWORMSOUNDWORMSOUNDWORMS AREAREAREARE USUALLYUSUALLYUSUALLYUSUALLY THETHETHETHE MOSTMOSTMOSTMOST SIGNIFICANTSIGNIFICANTSIGNIFICANTSIGNIFICANT

HEALTHHEALTHHEALTHHEALTH PROBLEMPROBLEMPROBLEMPROBLEM AFFECTINGAFFECTINGAFFECTINGAFFECTING SHEEPSHEEPSHEEPSHEEP ANDANDANDAND GOATSGOATSGOATSGOATS

� Their grazing habits

� Sheep graze close to the ground.

� Goats are often forced to graze close to the ground (despite their preference for grazing high).

� Sheep and goats are often kept on small pastures with high stocking rates.

� Their fecal pellets disintegrate easily.

� They graze close to their feces.

� The primary parasite affecting sheep and goats is a blood-sucking killer! Haemonchus contortus (barber pole worm)

RRRROUNDWORMSOUNDWORMSOUNDWORMSOUNDWORMS AREAREAREARE USUALLYUSUALLYUSUALLYUSUALLY AAAA MOREMOREMOREMORE SERIOUSSERIOUSSERIOUSSERIOUS PROBLEMPROBLEMPROBLEMPROBLEM ININININ

SMALLSMALLSMALLSMALL RUMINANTSRUMINANTSRUMINANTSRUMINANTS THANTHANTHANTHAN OTHEROTHEROTHEROTHER LIVESTOCKLIVESTOCKLIVESTOCKLIVESTOCK

� Immunity develops more slowly in small ruminants than other livestock.

� Females have relaxed immunity at the time of parturition.

� Few drugs are FDA-approved for small ruminants, especially goats.

→ The worms have developed resistance to drugs in all anthelmintic classes (more so than in any other species).

� Producers receive conflicting information about parasite control from other producers, veterinarians, extension agents, and internet.

4/6/2011

10

LLLLIFEIFEIFEIFE CYCLECYCLECYCLECYCLE OFOFOFOF STOMACHSTOMACHSTOMACHSTOMACH WORMSWORMSWORMSWORMS

BBBBARBERARBERARBERARBER POLEPOLEPOLEPOLE WORMWORMWORMWORMHaemonchus contortus

� Lives in the abomasum (“true” stomach).

� Sucks blood from host animal.

� Clinical signs: anemia (pale mucous membranes), edema (bottle jaw), loss of body condition and weight, poor hair coat, lethargy, and death.

4/6/2011

11

OOOOTHERTHERTHERTHER ROUNDWORMSROUNDWORMSROUNDWORMSROUNDWORMS

� Usually secondary in importance.

� Usually part of mixed worm infections.

� Cause digestive disturbances, e.g. diarrhea.

� Similar life cycles.

WORMWORMWORMWORM CONTROLCONTROLCONTROLCONTROL: : : : Pasture management

� Clean, safe pastures

� Pasture rotation/rest

� Minimum grazing heights > 3 inches

� Wait until dew has lifted before grazing

� Mixed-species grazingsmall ruminants � cows, horses

� Alternative foragese.g. Sericea lespedeza

� Browsing

� Proper stocking rates

4/6/2011

12

WORMWORMWORMWORM CONTROLCONTROLCONTROLCONTROL: : : : other strategies

� Zero grazing

� Good sanitation

� Nutrition � Protein supplementation

� Genetic selection

� Resistant breeds� Hair sheep, Gulf Coast Native� Kiko, Spanish, Myotonic

� Within breed selection� The 80-20 rule

WORMWORMWORMWORM CONTROLCONTROLCONTROLCONTROLFAMACHA© and Five Point Check© were developed in South Africa

FAMACHA© = FAffa MAlan CHArt

� Selective deworming using the Five Point Check©

1. FAMACHA© score2. Bottle jaw3. Body condition score4. Dag (fecal soiling) score5. Nasal discharge

�Always consider host resistance• Species• Breed • Age • Status

4/6/2011

13

WORMWORMWORMWORM CONTROLCONTROLCONTROLCONTROL::::

Fecal egg analysis

� Qualitative (simple fecal flotation) --of limited value.

� Quantitative (eggs per gram of feces)Modified McMaster technique (standard) →

� By itself, not a good indicator of the need to deworm.� All strongyle eggs look the same (except

nemotodirus)� Different worms produce different numbers of

eggs (barber pole worm is a prolific egg layer)� What’s a high FEC varies by worm, season, and

class of animal.� Not all species are pathogenic� Disease may occur at negative or low egg counts.

� Measure of pasture contamination.

� Do before and after fecal egg counts to determine drug effectiveness (resistance).

PPPPROPERROPERROPERROPER ANTHELMINTICANTHELMINTICANTHELMINTICANTHELMINTIC USEUSEUSEUSETREATMENT NOT PREVENTION

1. Dose according to weight.

2. Administer all drugs orally

3. Deposit drug into esophagus using oral dosing syringe with long, metal nozzle.

4. Give higher doses to goats (1.5 to 2 x sheep dose)

5. Deworm all new animals with drugs from two different chemical classes.

6. Do not dose everyone in the flock or herd.

7. Do not dose on a set schedule.

8. Test for drug resistance:� FECRT - before and after fecal egg counts� DrenchRite® / Larval development assay (LDA)

4/6/2011

14

LLLLUNGWORMSUNGWORMSUNGWORMSUNGWORMS

� Found in lungs and bronchial tissues.

� Some speceis require intermediate host (snails, slugs) to complete life cycle.

� Larvae are coughed up, swallowed, and passed in feces.

� Common in wet areas.

� Diagnose by fecal exam (first stage larvae in feces) and necropsy.� Difficult to diagnose.

� Common anthelmintics are effective against lungworms.

MMMMENINGEALENINGEALENINGEALENINGEAL WORMWORMWORMWORM

� Parasite of white-tail deer� Primarily harmless.

� Sheep, goats, alpaca, llamas, moose, and horses are unnatural hosts.� Causes damage to central nervous

system � death.

� Snails and slugs are intermediate host.� Larvae reach CNS 10-14 days after

ingestion of snail or slug.

� Common in wet areas and where there are a lot of deer.

4/6/2011

15

MMMMENINGEALENINGEALENINGEALENINGEAL WORMWORMWORMWORM

� Diagnose based on clinical symptoms and necropsy.� Many differential diagnoses.

� Treat with high, repetitive doses of anthelmintics and anti-inflammatory drugs.

� Ivermectin and fenbendazole are drugs of choice.

� Treatment may or many not be effective.

� Prevent by keeping sheep and goats away from snail and slug habitats and deer.

CCCCESTODESESTODESESTODESESTODES ((((TAPEWORMSTAPEWORMSTAPEWORMSTAPEWORMS))))

HostHostHostHost

Intermediate hostIntermediate hostIntermediate hostIntermediate host

� Moniezia sp.

� Echinoccus granulosusHydatid disease

� Taenia ovisOvine cysticerosisSheep measles

4/6/2011

16

TTTTAPEWORMSAPEWORMSAPEWORMSAPEWORMS –––– MMMMONIEZIAONIEZIAONIEZIAONIEZIA EXPANZAEXPANZAEXPANZAEXPANZA

� Require an intermediate host (soil/pasture mite) to complete their life cycle. � Mature tapeworms shed segments (proglottids), which are filled with eggs.

TTTTAPEWORMSAPEWORMSAPEWORMSAPEWORMS –––– MMMMONIEZIAONIEZIAONIEZIAONIEZIA EXPANZAEXPANZAEXPANZAEXPANZA

� Tend to be non-pathogenic.� Tend not to cause any problems,

especially in adult animals.� Research shows no benefit to

treatment.

� Extreme cases…� Blockage in large intestines.� Ill thrift and poor growth in

young animals.

� Only certain dewormers are effective against tapeworms.� Benzimidazoles

Safeguard®, Valbazen®� Praziquantel

4/6/2011

17

TTTTAPEWORMSAPEWORMSAPEWORMSAPEWORMS –––– SHEEPSHEEPSHEEPSHEEP MEASLESMEASLESMEASLESMEASLES

� Sheep and goats serve as intermediate host.

� Do not affect health of sheep or goat, but can cause cysts in meat and result in carcass condemnation � Not harmful to people

� Dogs (wild and domestic) are definitive hosts.

� Few symptoms in the dog.

� Control by deworming dogs and preventing dogs (wild and domestic) from eating carrion or raw meat.

TTTTREMATODESREMATODESREMATODESREMATODES ---- FLUKESFLUKESFLUKESFLUKES

� Common liver flukeFasciola hepatica

� Lives in bile ducts

� Causes liver damage → deathSimilar symptoms as barber pole worm

� 2-3 month life cycle.

� Snail serves as intermediate host

� Common in wet climates: Gulf states, California, Pacific Northwest, and Great Lakes region.

� Diagnose by fecal analysis and necropsy.

� Treat with albendazole (Valbazen®) and clorsulon (Ivermec Plus)

4/6/2011

18

PPPPROTOZOAROTOZOAROTOZOAROTOZOA –––– SINGLESINGLESINGLESINGLE CELLCELLCELLCELL ORGANISMSORGANISMSORGANISMSORGANISMS

�Eimeria spp.Coccidia

� Cryptosporidia sp.

� Giardia sp.

CCCCOCCIDIAOCCIDIAOCCIDIAOCCIDIA –––– EIMERIAEIMERIAEIMERIAEIMERIA SPSPSPSP....

� Complicated life cycle.

� Species-specific.

� All adult sheep and goats have coccidia in their guts.

� Primarily affects weanlings.

� Caused by stress, overcrowding, and poor sanitation.

� Damages lining of small intestines; damage can be permanent.

� Subclinical or clinical disease� Primary symptom is diarrhea

(smeared with blood or mucous).

4/6/2011

19

CCCCOCCIDIAOCCIDIAOCCIDIAOCCIDIA –––– EIMERIAEIMERIAEIMERIAEIMERIA SPSPSPSP....

� Diagnose with fecal analysis and clinical symptoms.

� Difficult to diagnose because…� Many causes of diarrhea

� Limitation of fecal analysis� Not all coccidia are pathogenic.

� Significant damage can occur before oocytes are shed in feces.

� Clinically normal animals have oocytes in feces.

CCCCOCCIDIAOCCIDIAOCCIDIAOCCIDIA –––– EIMERIAEIMERIAEIMERIAEIMERIA SPSPSPSP....

� Prevent with good sanitation and management.

� Dewormers have no effect on coccidia.

� Prevent with coccidiostats* in feed, mineral, or water.� Rumensin®� Bovatec®� Deccox®� Corid

� Treat with Corid or sulfa drugs (requires veterinary Rx).

*Can be toxic to equines and dogs.

4/6/2011

20

PPPPARASITEARASITEARASITEARASITE CONTROLCONTROLCONTROLCONTROL (GI (GI (GI (GI NEMATODESNEMATODESNEMATODESNEMATODES))))� Complex problem.� There is no magic bullet or recipe.� Requires an integrated approach.

animal - parasite - pasture� A new paradigm:

Treatment not preventionControl parasitism + manage drug resistance

� Requires critical understanding and thinking.

Additional information

� Maryland Small Ruminant Pagehttp://www.sheepandgoat.comdisease tab → internal parasites

� Southern Consortium for Small Ruminant Parasite Controlhttp://www.wormx.org

� Livestock parasitology 101http://www.sheepandgoat.com/articles/lvstkparasitology101.pdf

� Internal parasite (worm) controlhttp://www.sheep101.info/201/parasite.html

� Coccidiosis: deadly scourge of young lambs and kidshttp://www.sheepandgoat.com/articles/coccidiosis2011.html