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
Cooperia spp.-Life Cycle
Direct. PPP = 15-18d
Cooperia spp.-Site of Infection
Small Intestine
Cooperia spp.-Pathogenesis and Lesions
Mild pathogens in calves
Cooperia spp.-Clinical Signs
Watery diarrhea
Cooperia spp.-Diagnosis
Fecal egg counts, trichostrongyloid L3, necropsy
Cooperia spp.-Treatment and Prevention
Environment and animal husbandry
Older cows devel. immunity
Oesophagostomum spp.-Common Name
Nodular worm, pimply worm
Related to horse strongyles
Oesophagostomum spp.-Hosts
Cattle, sheep, goats
Oesophagostomum spp.-Identification
Adults: 2.5cm, white
L4: small and large intestinal walls, nodules may be 0.5cm
Eggs: strongyloid, oval, up to 85um, thin shell, outer surface of shell smooth
Oesophagostomum spp.-Life Cycle
Direct. PPP = 45 d
Eggs in feces hatch→ devel. to L3→ L3 ingested and enter wall of small and large intestine→ devel. to L4 in nodules→ adult emerge
Oesophagostomum spp.-Site of Infection
Adults: lumen of large intestine
L4: wall of small or large intestine
Oesophagostomum spp.-Pathogenesis and Lesions
Anorexia caused by intestinal discomfort
Oesophagostomum spp.-Clinical Signs
Acute: seldom seen, caused by larval stages, impairs absorption, temperature, diarrhea and dehydration
Chronic: due to larval and adults, anorexia, diarrhea, intussusception
Oesophagostomum spp.-Diagonsis
Clinical signs, fecal exam for eggs and strongyloid L3, necropsy
Oesophagostomum spp.-Treatment and Prevention
Anthelmintics, management, no immunity
Dictyocaulus viviparus-Common Name
Lung worm
Disease: Husk, hoose, verminous pneumonia
Dictyocaulus viviparus-Hosts
Cattle
Dictyocaulus viviparus-Identification
Adults: slender, white nematode, 3-10cm
L1: found in fresh feces, 500um
Dictyocaulus viviparus-Life Cycle
Direct. PPP = 24d
Eggs→ hatch to L1 and coughed up and passed in feces→ devel. to L3→ migrate to herbage (or dispersed by fungi)→ ingested by DH→ L3 penetrate intestinal mucosa→ reach lung by lymphatics and blood vessels→ mature to adult in trachea and bronchi
Dictyocaulus viviparus-Site of Infection
Trachea and bronchi
Dictyocaulus viviparus-Pathogenesis and Lesions
Penetration Phase (d 1-7)-larval migration, no clinical signs Prepatent Phase (d 8-24)-larvae devel. to adults in lungs, alveolitis and bronchitis Patent Phase (d 25-60)-presence of adult worms in lungs, bronchitis and pneumonia Postpatent Phase (d 61-90)-if animal survives recovery starts, relapse may occur, entire lungs are diseased
Dictyocaulus viviparus-Clinical Signs
Bouts of coughing at rest, postpatent parasitic bronchitis–dissolution and aspiration of dead or dying worms at end of infection
Dictyocaulus viviparus-Diagnosis
Clinical signs, history, endemic area, identification of L1 with Baermann method, necropsy
Dictyocaulus viviparus-Treatment and Prevention
Anthelmintics, management, vaccine (Europe)
