The anemia caused by Trypanosoma conogolense TREU 112 in Holstein calves was of moderate severity and normochromic, macrocytic in the acute phase changing to normochromic, normocytic with chronicity. The anemia was hemolytic and responsive as shown by sharply decreased myeloid:erythroid ratio and increased mean corpuscular volume. 51Cr red cell labelling studies showed that red cell lifespan was halved in the acute phase and there was an increase in plasma volume. Surface organ counting of liver showed it to be the major site of red cell destruction. The anemia was partly dilutional as a result of the increased plasma volume and primarily hemolytic likely of a non-specific immune (innocent bystander) pathogenesis.
References
1.
AdlerH.L.RoeslerF.B.:
Introduction to Probability and Statistics, p. 333,
5th ed.; W. H. Freeman, San Francisco, 1972
2.
DacieJ.V.LewisS.M.:
Practical Haematology, p. 356,
4th ed.; J. and A. Churchill, London, 1968
3.
FiennesR.N.T.-W.:
Haematological studies in trypanosomiasis of cattle.Vet Rec66:
423–434, 1954
4.
GomoriG.:
Microtechnical demonstration of iron.Am J Pathol12:
655–663, 1936
5.
International Committee for the Standardization of Hematology: Recommended methods for surface counting to determine sites of red cell destruction.
Br J Haematol30:
249–254, 1975
6.
KampschmidtR.F.UpchurchH.:
Lowering of plasma iron concentration in the rat with leukocytic extracts.Am J Physiol216:
1287–1291, 1969
7.
KobayashiA.TizardI.R.WooP.T.K.:
Studies on the anemia in experimental African trypanosomiasis. II. The pathogenesis of the anemia in calves infected with Trypanosoma congolense.Am J Trop Med Hyg25:
401–406, 1976
8.
LososG.J.IkedeB.O.:
Review of pathology of diseases in domestic and laboratory animals caused by Trypanosoma congolense, T. vivax, T. brucei, T. rhodesiense and T. gambiense.Vet Pathol9(Suppl):1–71,
1972
9.
LumsdenJ.H.ValliV.E.O.McSherryB.J.WilloughbyR.A.:
The piromen test as an assay of bone marrow: granulocyte reserves in the calf. I. Studies on bone marrow and peripheral blood leukocytes.Can J Comp Med38:
56–64, 1974
10.
MamoE.HolmesP.H.:
The erythrokinetics of Zebu cattle chronically infected with Trypanosoma congolense.Res Vet Sci18:
105–106, 1975
11.
MaxieM.G.ValliV.E.O.RobinsonG.A.TruscottR.B.McSherryB.J.:
Studies with radioactive endotoxin. I. Clearance of 51Cr-labelled endotoxin from the blood of calves.Can J Comp Med38:
347–366, 1974
12.
McSherryB.J.Van DreumelA.A.RobinsonG.A.:
Apparent half-time of bovine red cells labelled in vitro with chromate-Cr51 and autotransfused into 10 normal calves.Can Vet Jour7:
176–179, 1969
13.
NaylorD.C.:
The haematology and histopathology of Trypanosoma congolense infection in cattle. II. Hematology (including symptoms).Trop Anim Health Prod3:
159–169, 1971
14.
TartourG.IdrisO.F.:
Iron metabolism in Trypanosoma congolense infection in Zebu cattle: serum iron and serum iron-binding capacity.Res Vet Sci15:
24–32, 1973
15.
ValliV.E.O.ForsbergC.M.RobinsonG.A.:
The pathogenesis of Trypanosoma congolense infection in calves. I. Clinical observations and gross pathological changes.Vet Pathol15:
608–620, 1978
16.
ValliV.E.O.ForsbergC.M.:
The pathogenesis of Trypanosoma congolense infection in calves. V. Quantitative histological changes. Vet Pathol (accepted for publication)
17.
ValliV.E.O.HullandT.J.McSherryB.J.RobinsonG.A.GilmanJ.P.W.:
The kinetics of haematopoiesis in the calf. I. An autoradiographical study of myelopoiesis in normal, anaemic and endotoxin treated calves.Res Vet Sci12:
535–580, 1971
