*/ ’ .rn FROM AN EXPERIMENT ...
*/
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.rn
FROM AN EXPERIMENT
PATHOLOGY BETWEEN ZEBU
c
AND NDAMA CATTLE DURING NATURAL INFECTION
0
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Sd ,9
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BY PATHOGEN IC TRY PAWSOMES
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24
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By Saydil M. TOURE (+>
The field experinrent hereafter reported was aimed at ctimparing Zebu
and Ndama cattle during natural Trypanosomiasis as observed in an areaof
tsetse fly challenge and it lasted 8 months.
Groups of cattle including 29 Ndama (among them 4 cross-breed : 13/ 16
Ndama - 3/ 16 Zebu) and 18 zaltrus were maintained in the village of Missira,
Sénegal (13O40’ N o r t h - 16’ 30’ West) where Clossinu morsitam suho~~s~tans
and C.paZpaZiu gmbitns*iu usually occur.
Previous to the experiment, a11 the animais were apparently in excel-
lent condition but further analyses revealed many cases of parasitism (blood
parasites coneisting mainly in !I’htii2~7.(z muti~lc; and microfilariae of Se-t@&;
common Helminth par;isites).
‘I’hc animais had high values of PCV in despite
thei r parasites. Serulogical. analyses by fluorescent antibody test, using
Y. t~rucei as ant i gen , suggesttid strong evidence that the groups ol- cattle
purchased outside thtL tsti:tse belt were free of Trypanosomiasis, with the
exception of LWO Ndaw-c1 which obviously urigindted Erum an rndemic area ald
were even parasitaemic.
During thc: oxperimeutal p e r i o d t h e following facts were observed, ta-
king into account that some chronic cases in the zebus were artificially
induced by drug administration.
1. fhe prepatenLy period of some of the Ndama did not difier significantly from
that o f t h e zebtls. i!owever for other Ndama it was long or even very long.
ei Inhtltut sénegalais d e Kecherches a g r i c o l e s - Service de Parasitologie du Laboratoire
tlat roiial de 1’Elevage et de Recherches vetérinaires - B.P. 2057, DAKAR (Senégal)
C:0nurru~lication à l a 16’ réunion du Comité scientifique international de la Recherche sur
les ‘I’rypanOSOmiaSeS et leur contrôle, Yaoundé 29 octobre-3nov 79
.
- 2
2. Parasitaemia was always more intensive in the zebus than it was in the
Ndama. The infections were predominantly caused by T.vivu3: in both breeds
but !l’.conpbzus occurcd in higher percenLage in the humpless cattle than
in the zebus. Mi ce inocul.ation showed only one case of T.brucei in a Nda-
ma having a mixed infection..
3. Temperature during parasitaemia was significanfly higher in the zebuo than
it was in the Ndama goups.
4. In a11 diseaséd animais anaemia was related to parasitaemia.Low PCV was
more evident in 1’. o~)YlyoZen~~o infection6. Attempts to regenerate the ana-
emia seemed to bc more succestiful in the Ndama groups in which the hae-
matocrite fluctuated around normal. values. Many of the Ndama even had
high PCV during the last months of the experiment.
5. Blood cells countin.g indicat.ed Low number of erythrocytes in diseased ani-
mals, either zebu or Ndama. During the first weeks of the infection there
was, in percentage, a reduced number of neutrophil white cells and an in-
creasing of eosinophils and Lymphocytes in the Ndüma ; on the other hand,
in the zebus, the neutrophils were increased and the Lymphocytes reduced.
The proportions were somewhat modified before the death : eosinophils de-
creased in the Ndama. and neutrophils still increased in the sebus.
6. Total globulin level was higher in the Ndama than in the zebus.
7, Trypanosome specific antibodies analysis by indirect immunofluoresceuce
indicated higher titers in the Ndama groups.
8. IgM titers increased slightly in the Ndama but sharply in the treated ze-
bus. There were no precisr data on LgC globulins.
9. Clinically the main symptoms were about the same in the two breeds. It ap-
peared that pregnant zebu cows gave premature calves which died later.
10. Acute or chronic disease occured in the Ndama as well as in the zebus. It
was not observed conspicuous differences in organic damages according to
the breeds, but only according to the length of the desease :
- 3
a) acute disease was characterized by congestive tissue damages and at-
temptsfrom the retiaulo-endothelial system to regenerate the anaemia
and to des troy the parasites ;
b) in chronic cases, organic hypoplasia by cellular depletion and tissu-
lar degeneration were predominant.
In a11 cases death was suspected to result from a heart failure. Qua-
sinormal values of PCV could not be considered as a criterion of survival
probability for the diseased animals.
The results of necropsy and histopathological findings on Zebu and
Ndama indicated many types of organ damages, according to the species of
Trypanosomes, but there were no evidence that these were pathognomonic.
11. In comparing the groups, it appeared that the sahelian zebus were high-
ly susceptible to Trypanosomiasis caused by T.vivax or by T.congoZenoc
and died when submit ted to permanent fly challenge. Even treated, they
died as soon as the medical tare was stopped. The Ndama cattle which ca-
me from outside the tsetse belt also suffered from acute or chronic disea-
se when they were placed into the infested area and death occured;However
some Ndama cattle were highly resistant to the diseaee and under permanent
Ai11 lenpe di.4 net suffer froc Trypanooomiosis,
without any particular tare
heing t aken on them. These except ional animals ought to be carefully stu-
died iii ;II!. 4öpe~Cs, mailr ly i;ene tic sud iumunologic,
’
.rn
FROM AN EXPERIMENT
PATHOLOGY BETWEEN ZEBU
c
AND NDAMA CATTLE DURING NATURAL INFECTION
0
/
Sd ,9
.<
BY PATHOGEN IC TRY PAWSOMES
P
.
‘i,. C’
.;<
24
1.
_.
.-.^
-.*-
;, ‘2
- r..
4
---I--
-
-
By Saydil M. TOURE (+>
The field experinrent hereafter reported was aimed at ctimparing Zebu
and Ndama cattle during natural Trypanosomiasis as observed in an areaof
tsetse fly challenge and it lasted 8 months.
Groups of cattle including 29 Ndama (among them 4 cross-breed : 13/ 16
Ndama - 3/ 16 Zebu) and 18 zaltrus were maintained in the village of Missira,
Sénegal (13O40’ N o r t h - 16’ 30’ West) where Clossinu morsitam suho~~s~tans
and C.paZpaZiu gmbitns*iu usually occur.
Previous to the experiment, a11 the animais were apparently in excel-
lent condition but further analyses revealed many cases of parasitism (blood
parasites coneisting mainly in !I’htii2~7.(z muti~lc; and microfilariae of Se-t@&;
common Helminth par;isites).
‘I’hc animais had high values of PCV in despite
thei r parasites. Serulogical. analyses by fluorescent antibody test, using
Y. t~rucei as ant i gen , suggesttid strong evidence that the groups ol- cattle
purchased outside thtL tsti:tse belt were free of Trypanosomiasis, with the
exception of LWO Ndaw-c1 which obviously urigindted Erum an rndemic area ald
were even parasitaemic.
During thc: oxperimeutal p e r i o d t h e following facts were observed, ta-
king into account that some chronic cases in the zebus were artificially
induced by drug administration.
1. fhe prepatenLy period of some of the Ndama did not difier significantly from
that o f t h e zebtls. i!owever for other Ndama it was long or even very long.
ei Inhtltut sénegalais d e Kecherches a g r i c o l e s - Service de Parasitologie du Laboratoire
tlat roiial de 1’Elevage et de Recherches vetérinaires - B.P. 2057, DAKAR (Senégal)
C:0nurru~lication à l a 16’ réunion du Comité scientifique international de la Recherche sur
les ‘I’rypanOSOmiaSeS et leur contrôle, Yaoundé 29 octobre-3nov 79
.
- 2
2. Parasitaemia was always more intensive in the zebus than it was in the
Ndama. The infections were predominantly caused by T.vivu3: in both breeds
but !l’.conpbzus occurcd in higher percenLage in the humpless cattle than
in the zebus. Mi ce inocul.ation showed only one case of T.brucei in a Nda-
ma having a mixed infection..
3. Temperature during parasitaemia was significanfly higher in the zebuo than
it was in the Ndama goups.
4. In a11 diseaséd animais anaemia was related to parasitaemia.Low PCV was
more evident in 1’. o~)YlyoZen~~o infection6. Attempts to regenerate the ana-
emia seemed to bc more succestiful in the Ndama groups in which the hae-
matocrite fluctuated around normal. values. Many of the Ndama even had
high PCV during the last months of the experiment.
5. Blood cells countin.g indicat.ed Low number of erythrocytes in diseased ani-
mals, either zebu or Ndama. During the first weeks of the infection there
was, in percentage, a reduced number of neutrophil white cells and an in-
creasing of eosinophils and Lymphocytes in the Ndüma ; on the other hand,
in the zebus, the neutrophils were increased and the Lymphocytes reduced.
The proportions were somewhat modified before the death : eosinophils de-
creased in the Ndama. and neutrophils still increased in the sebus.
6. Total globulin level was higher in the Ndama than in the zebus.
7, Trypanosome specific antibodies analysis by indirect immunofluoresceuce
indicated higher titers in the Ndama groups.
8. IgM titers increased slightly in the Ndama but sharply in the treated ze-
bus. There were no precisr data on LgC globulins.
9. Clinically the main symptoms were about the same in the two breeds. It ap-
peared that pregnant zebu cows gave premature calves which died later.
10. Acute or chronic disease occured in the Ndama as well as in the zebus. It
was not observed conspicuous differences in organic damages according to
the breeds, but only according to the length of the desease :
- 3
a) acute disease was characterized by congestive tissue damages and at-
temptsfrom the retiaulo-endothelial system to regenerate the anaemia
and to des troy the parasites ;
b) in chronic cases, organic hypoplasia by cellular depletion and tissu-
lar degeneration were predominant.
In a11 cases death was suspected to result from a heart failure. Qua-
sinormal values of PCV could not be considered as a criterion of survival
probability for the diseased animals.
The results of necropsy and histopathological findings on Zebu and
Ndama indicated many types of organ damages, according to the species of
Trypanosomes, but there were no evidence that these were pathognomonic.
11. In comparing the groups, it appeared that the sahelian zebus were high-
ly susceptible to Trypanosomiasis caused by T.vivax or by T.congoZenoc
and died when submit ted to permanent fly challenge. Even treated, they
died as soon as the medical tare was stopped. The Ndama cattle which ca-
me from outside the tsetse belt also suffered from acute or chronic disea-
se when they were placed into the infested area and death occured;However
some Ndama cattle were highly resistant to the diseaee and under permanent
Ai11 lenpe di.4 net suffer froc Trypanooomiosis,
without any particular tare
heing t aken on them. These except ional animals ought to be carefully stu-
died iii ;II!. 4öpe~Cs, mailr ly i;ene tic sud iumunologic,