An experimental field study on the build up of lungworm infections in cattle.
The build up of lungworm infections was studied in four groups of calves. Calves of Group 1 were infected experimentally with 6 x 10 larvae during the first 3 weeks after turnout. The pasture of Group 2 was contaminated with approximately 35,000 larvae in June and the pasture of Group 3 with approximately 1.3 million larvae in August. Group 4 served as the helminth free control group for challenge infections with 5,000 larvae in October. In Group 1 faecal larval counts increased 5 weeks after the beginning of patency and decreased after another 3 weeks, indicating the development of immunity after the second lungworm generation. In contrast, the development of immunity in Groups 2 and 3 occurred after the first lungworm generation as maximal faecal larval counts were seen within 3.5 weeks after the beginning of patency. Infection levels were highest in Group 3 which was the only group showing clinical signs. These signs became worse after oxfendazole treatment.
Eysker
M
M
Department of Infectious Diseases and Immunology, Utrecht University, The Netherlands.
Boersema
J H
JH
Cornelissen
J B
JB
Kooyman
F N
FN
de Leeuw
W A
WA
Saatkamp
H W
HW
D000821:Animal Feed / Q000469:parasitology; D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis; D002353:Carrier State / Q000276:immunology / Q000469:parasitology / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000469:parasitology / Q000473:pathology*; D004021:Dictyocaulus / Q000276:immunology / Q000302:isolation & purification; D004022:Dictyocaulus Infections / Q000276:immunology / Q000469:parasitology / Q000473:pathology*; D005243:Feces / Q000469:parasitology; D005260:Female
D000909:Antibodies, Helminth