ParasitesDr. Dipa Brahmbhatt VMD, MPH, MS

Chapter 17

Objectives

• ID Common endoparasites in small ruminants• Clinical signs associated with parasites• Diagnosis• Treatments

Reading Assignment

Chapter 17: Common Ovine and Caprine DiseasesKnow table 17 -3: Parasites

Key terms

• Fecal flotation• ELISA• Baerman technique• Skin scrapings• Pre patent period• Direct life cycle• Indirect lifecycle

Figure 6-61 Baermann apparatus is used to recover larvae of roundworms from feces, soil, or animal tissues. This apparatus is most useful in recovering larvae of lungworms.

(Reprinted from Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Abomasum

Family: Trichostrongyloidea

Haemonchus Contortus

• Haemonchus contortus – barberpole worm/ wire worm– 1” (25 mm)– Abomasum of

small ruminants– feeds on blood– Clinical signs• anemia, bottle jaw, chronic weight loss• death

PPP: 17 – 21 days

Male bursa RIght

Clinical signs Haemonchus

• ‘bottle jaw’: hypoproteinemia and anemia.

• usually late winter.

Figure 6-34 Characteristic trichostrongyle-type ova of the bovine trichostrongyles. These oval, thin-shelled eggs contain four or more cells. They measure 70 to 120 µm long. Some of these ova can be identified by their respective genus; however, identification is usually difficult because mixed infections are common.

(From Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Adults in the abomasum.

Barberpole worm

TX: Levimasole, ivermectin, doramectin, Moxidectin, albendazole, morantel tartate, eprinomectin, tetramisole

Ostertagia ostertagi

• Ostertagia ostertagi (brown stomach worm)– 1/2” (10 mm) adult worm; abomasum– most serious impact on calves– disrupt gastric acid secretion– Clinical signs

• diarrhea• ill thrift‐• poor feed conversion

Male bursa left

PPP: 16 – 23 days

Ostertagia ostertagi

TX: Fenbendazole, ivermectin, doramectin, morantel tartate, moxidectin

Trichostrongylus axei

• Trichostrongylus axei– “Bankrupt worm”– Small stomach worm

– Adults ~1/4” (4 8 ‐mm); abomasum– Clinical signs– Diarrhea– dehydration– bottle jaw– emaciation

PPP: 21 days

TX: Fenbendazole, ivermectin, doramectin, Moxidectin, albendazole, morantel tartate, eprinomectin

Small Intestine

Nematodirus

• Nematodirus spp.– “Thin necked intestinal worms”– N. battus is more pathogenic– SI– Diarrhea, Anorexia

B = typical strongyle egg

PPP: 14 - 21 days

TX: Fenbendazole, albendazole, ivermectin, Moxidectin, albendazole, morantel tartate, levamisole

Figure 6-35 Characteristic large ova of Nematodirus species. In standard fecal flotation, the eggs of Nematodirus species are larger than those of other bovine trichostrongyles (150 to 230 µm by 80 to 100 µm), have tapering ends, and have four to eight cells.

(From Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Strongyloides papillosus

• Family: Rhabditodea• Threadworm• CS: foot rot, diarrhea• TX: eprinomectin,

ivermectin• ZOONOTIC

PPP: 1 – 2 weeks

Trichostrongylus Colubriformis

• Hair worm, black scour worm

• CS: diarrhea, +/- bottlejaw, dec. weight gain,

• PPP: 21 days• ZOONOTIC

TX: Fenbendazole, doramectin, Moxidectin, morantel tartate, eprinomectin

Figure 6-36 Characteristic ova of Moniezia species. The eggs of Moniezia expansa are triangular or pyramidal and 56 to 67 µm in diameter. The eggs of Moniezia benedini are square or cuboidal and approximately 75 µm in diameter.

(From Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Cooperia spp.

• Cooperia punctata or pectinata

• Cattle bankrupt worm• CS: decreased growth

and anorexia• PPP: 21 days

TX: Fenbendazole, Levimasole, ivermectin, doramectin, Moxidectin, albendazole, morantel tartate, eprinomectin

Bunostomum trigonocephalumBunostomum trigonocephalum

• TrichostrongloideaTrichostrongloidea– Bunostomum Bunostomum

trigonocephalum:trigonocephalum:– hookwormshookworms– Larger than strongyle Larger than strongyle

eggseggs– Diarrhea, anemia, Diarrhea, anemia,

weight loss, death – weight loss, death – young animalsyoung animals

– PPP: 2 monthsPPP: 2 months

Courtesy of Dr. Dietrich Barth, Merial

TX: Fenbendazole, ivermectin, doramectin, Moxidectin, eprinomectin

Monieza expansaMonieza expansa

•CESTODES– Monieza expansaMonieza expansa

•Not very pathogenicNot very pathogenic•PPP: 40 days

Moniezia expansa,egg. Courtesy of Merial

TX: Fenbendazole, albendazole, dichlorophen, lead, arsenate, niclosamide

Cecum and Colon

Oesphagostomum columbianumOesphagostomum columbianum– Strongylidae Strongylidae

• Oesphagostomum Oesphagostomum columbianum: columbianum: nodular wormnodular worm

• cecum, colon• anorexia; severe,

constant, dark, persistent, fetid diarrhea with fly strike; weight loss; and death

• Adults: cysts in GIAdults: cysts in GI• PPP: 40 daysPPP: 40 days

Oesphagostomum columbianumOesphagostomum columbianum

Oesophagostomum gross lesions (nodules), abomasum, sheep. Courtesy of Dr. Raffaele Roncalli

TX: Albendazole, Eprinomectrin, Moxidectin, Doramectin, albendazole, morantel tartate, levamisole

Chabertia ovina

• Large bowel worm• CS: anemia• PPP: 2 months

TX: Albendazole, Fenbendazole, ivermectin

Trichuris ovis

• Whipworm• CS: hemorrhage –

cecum with fatal infections

• PPP: 2 months

TX: Eprinomectin, Fenbendazole, ivermectin

Lung worms

Dictyocaulus filaria

• Lungworm• CS: cough, cyanosis,

dyspnea• PPP: 28 days• Baerman technique

TX: Ivermectin, Eprinomectrin, Moxidectin, Doramectin, fenbendazole, levamisole

Figure 6-38 Representative eggs and larvae of Dictyocaulus species, or cattle lungworms.

(From Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Protostrongylus

• Protostrongylus rufescens, P. rushi, P. stilesi

• Bighorn sheep lungworm• Transmission:

transplacental, snails• CS: predisposes to

pneumonia• PPP: 35 days• DX: Fecal baerman• Flukes: liver and bile TX: ivermectin, albendazole, fenbendazole

Muellerius capillaris

• Goat lungworms• May predispose to

pneumonia• Baerman techniique• snail

TX: ivermectin, albendazole, fenbendazole

Figure 6-39 First-stage larva of Muellerius capillaris, the “hair lungworm” of sheep and goats. First-stage larvae are 230 to 300 µm long. The larval tail has an undulating tip and a dorsal spine.

(From Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Liver

Fasciola hepatica• Fasciola hepatica • Liver flukes

– Live in bile ducts as adults– Aquatic snails = intermediate host– CS: anemia, weight loss, decreased performance, hepatitis, death

• PPP: 10 – 12 weeks–Eggs: are heavy sedimentation is recommended

TX: Clorsulon, nitroxynil, rafoxanide

ZOONOTIC

Figure 6-37 Characteristic operculated ovum of Fasciola hepatica, the liver fluke of cattle, sheep, and other ruminants. The eggs measure 140 by 100 µm and are yellowish-brown and oval.

(From Hendrix CM, Robinson E: Diagnostic parasitology for veterinary technicians, ed 3, St Louis, 2006, Mosby.)

Thysanosoma actinoides

• Fringed tapeworm• Sheep• CS: weight loss• Liver condemned• PPP: 30 days• Dx: proglottids – feces• Tx: Fenbendazole and

albendazole

ID necropsy

• Taenia hydatigena• Echinoccocus granulosus• Taenia ovis• Taenia multiceps

References• Large animal clinical procedures for veterinary technicians,

Elizabeth A. Hanie, 2006• http://www.caes.uga.edu/publications/pubDetail.cfm?pk_ID=

6196• http://courses.cals.uidaho.edu/avs/avs471/Lectures/Lectures

%202010/Lecture%20Parasites%20notes.pdf• http://cal.vet.upenn.edu/projects/dxendopar/parasitepages/

trematodes/Fhepatica.htm• http://cal.vet.upenn.edu/projects/dxendopar/

index.html#fecal• http://www.sheepandgoat.com/HairSheepWorkshop/

parasitism.html• http://cal.vet.upenn.edu/projects/merial/Nematodes/

Table1.htm

References• http://www.vetmed.wisc.edu/pbs/vetpara/tutorial2.html• http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/

toc_22400.htm• http://instruction.cvhs.okstate.edu/jcfox/htdocs/clinpara/

lst41_50.htm• http://instruction.cvhs.okstate.edu/jcfox/htdocs/clinpara/

lecture.htm• http://cal.vet.upenn.edu/projects/merial/index.html• Laboratory procedures for Veterinary Technicians, 5th edition, 2007,

Hendrix C.M; Sirois M.• K Holtgrew-Bohling , Large Animal Clinical Procedures for Veterinary

Technicians, 2nd Edition, Mosby, 2012, ISBN: 97803223077323

References

• http://wwwnc.cdc.gov/eid/article/17/7/10-1519-f1.htm

• http://www.extension.org/pages/19680/goat-other-parasites