Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-13T01:56:02.111Z Has data issue: false hasContentIssue false
  • English
  • Français

Haemonchus contortus - haematological changes in lambs during prolonged exposure to daily and weekly doses of infective larvae

Published online by Cambridge University Press:  06 April 2009

S. L. Pradhan  and
I. L. Johnstone
Get access Rights & Permissions [Opens in a new window]

Extract

Thirty-five lambs (14 weeks old), the progeny of Border Leicester rams mated with Border Leicester × Merino ewes were divided at random into two groups. Seventeen lambs received 3500 Haemonchus contortus larvae at weekly intervals (weekly group) and 18 lambs received 500 larvae each day (daily group). The dosage was decreased to 1400 and 200 larvae respectively after 8 weeks.

The daily infection with a small number of larvae induced a severe anaemic condition with the blood picture falling to 7% PCV; 2% Hb conc. and 1·6m/mm3 RBC count in 78 days. The anaemia with weekly dosing of larvae was less severe with equivalent figures of 10–12% PCV; 4% Hb conc and 3·6m/mm3 RBC count.

Two phases were observed in the changes in the sodium (Na+e) and potassium (K+e) electrolyte concentrations. In the first phase (K+e) increased and (Na+e) decreased, while in the second phase both electrolytes increased. The influx of young red blood cells into the circulation is considered as the factor responsible for these changes.

Type
Research Article
Information
Parasitology , Volume 64 , Issue 1 , February 1972 , pp. 153 - 160
Copyright
Copyright © Cambridge University Press 1972

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Charleston, W. A. G. (1964). Comparison of blood and bone marrow changes in lambs with haemonchosis and in lambs repeatedly bled. Journal of Comparative Pathology 74, 223–40.CrossRefGoogle ScholarPubMed
Christie, M. G., Brambell, M. R. & Charleston, W. A. G. (1964). Resistance to haemonchosis in sheep following plenothiazine treatment of a previous infestation. Research in Veterinary Science 5, 202–12.CrossRefGoogle Scholar
Christie, M. G. & Brambell, M. R. (1966). Acquired resistance to Haemonchus contortus in young lambs. Journal of Comparative Pathology 76, 206–16.CrossRefGoogle ScholarPubMed
Dacie, J. V. & Lewis, S. M. (1963). Practical Haematology, 3rd ed.London: J. and A. Churchill Ltd.Google Scholar
Dineen, J. K., Donald, A. D., Wagland, B. M. & Offner, Jan (1965). The dynamics of the host-parasite relationship. III. The response of sheep to primary infection with Haemonchus contortus. Parasitology 55, 515–25.CrossRefGoogle Scholar
Evans, J. V., Blunt, M. H. & Southcott, W. H. (1963). The effects of infection with Haemonchus contortus on the sodium and potassium concentrations in the erythrocytes and plasma in sheep of different haemoglobin types. Australian Journal of Agricultural Research 14, 549–58.CrossRefGoogle Scholar
Manton, V. J. A., Peacock, R., Poynter, D., Silverman, P. H. & Terry, R. J. (1962). The influence of age on naturally acquired resistance to Haemonchus contortus in lambs. Research in Veterinary Science 3, 308–14.CrossRefGoogle Scholar
Mulligan, W., Gordon, H. Mcl., Stewart, D. F. & Wagland, B. M. (1961). The use of irradiated larvae as immunising agents in Haemonchus contortus and Trichostrongylus colubriformis infections of sheep. Australian Journal of Agricultural Research 12, 1175–87.CrossRefGoogle Scholar
Pradhan, S. L. (1966). The population dynamics of Haemonchus contortus in lambs with particular reference to haematological changes. M.Sc. thesis, Univ. N.S.W. Australia.Google Scholar
Pradhan, S. L. & Johnstone, I. L. (1972). Haemonchus contortus - the effect on lambs of prolonged exposure to daily and weekly doses of infective larvae. Parasitology 64, 143–52.CrossRefGoogle ScholarPubMed
Wootton, J. D. P. (1964). Micro-Analysis in Medical Biochemistry 4th Ed.London: J. and A. Churchill Ltd.Google Scholar