Bovine Nematodes Flashcards
Ostertagia ostertagi-Common Name
Brown stomach worm
Related to horse strongyles
Ostertagia ostertagi-Hosts
Cattle
Ostertagia ostertagi-Identification
Adults: 1 cm, slender, reddish-brown
Larvae: microscopic
Eggs: typical trichostrongyloid, oval, up to 85 um, thin shelled, outer surface of shell smooth, contains morula
Ostertagia ostertagi-Life Cycle
Direct. PPP = 21 d
L3 infective stage
Eggs released in feces→ devel. to L3 in fecal pat→ L3 migrate to herbage→ ingest L3 while grazing→ exsheaths in rumen→ further devel. in abomasal gland
Ostertagia ostertagi-Site of Infection
Abomasum
Ostertagia ostertagi-Pathogenesis and Lesions
Caused by L3 to immature adult in the gastric glands
- reduction in functional gastric glands responsible for producing acidic proteolytic gastric juice; reduction in acidity of abomasal fluid
- thickened gastric mucosa; raised nodules called “Moroccan leather”
- Increased plasma pepsinogen
Ostertagia ostertagi-Clinical Signs
Type I-Summer Ostertagiosis
-In calves during first grazing season
-Morbidity high, mortality rare if treatment is instituted in 3 days
-Profuse watery diarrhea, persistant and bright green
Type II-Winter Ostertagiosis
-In calves following first grazing season with arrested L4
-Profuse watery diarrhea; intermittent
-More “bottle jaw” (submandibular edema)
-Clinical disease low, mortality high unless treatment instituted
Ostertagia ostertagi-Diagnosis
Clinical signs, season, grazing history Fecal egg counts -Type I have epg -Type II often negative Culture and identification of L3 Elevated plasma pepsinogen levels Necropsy % adults to larvae high in Type I and low in Type II
Ostertagia ostertagi-Treatment and Prevention
Type I
-Anthelmintics, move cattle to “safe pasture”
Type II
-Anthelmintics effective against arrested L4, larvae and adults
Limit exposure, but exposure will cause immunity
Haemonchus placei-Common Name
Barber pole worm, wireworm
Haemonchus placei-Hosts
Cattle
Haemonchus placei-Identification
Adults: 2-3 cm, white ovaries wind spirally around the blood-filled intestine producing “barber pole” appearance
Eggs: trichostrongyloid, oval, up to 85 um, thin shelled, outer surface of shell smooth
Haemonchus placei-Diagnosis
History, clinical signs, fecal worm egg counts, trichostrongyloid L3, necropsy
Cooperia spp.-Hosts
Cattle, sheep, goats
Cooperia spp.-Identification
Adults: less than 9mm, large bursa, “watch spring” posture
Eggs: trichostrongyloid, oval, up to 85 um, thin shelled, outer surface of shell smooth