Nq. Hailat et al., EQUINE BABESIOSIS ASSOCIATED WITH STRENUOUS EXERCISE - CLINICAL AND PATHOLOGICAL-STUDIES IN JORDAN, Veterinary parasitology, 69(1-2), 1997, pp. 1-8
Clinical, haematological and pathological studies were undertaken in J
ordan in a stud of 103 racing horses clinically suffering from babesio
sis and apparently healthy animals. Out of 47 horses which participate
d in strenuous exercise, three mares showed sudden onset of immobility
and reluctance to move and two mares died. Clinical examination revea
led that these five horses (group I) had fever, anorexia, weakness and
severe icterus and, in two mares, haemoglobinuria. Haematological exa
mination revealed that all five horses were heavily parasitized with B
abesia equi. This was also found in four horses (group 2) with no evid
ence of clinical babesiosis. In group 3 (94 horses), neither clinical
signs nor B. equi were observed in the blood. The horses in group 1 an
d 2 recovered after treatment with imidocarb. When the mean values of
white blood cell count, red blood cell count, haemoglobin and packed c
ell volume in group 1 were compared with those for groups 2 and 3, a s
ignificant difference was found (P <0.05). A significant difference wa
s also found when the mean values were compared before and after treat
ment. Examination of serum total protein, bilirubin and serum enzymes
revealed a significant decrease in the mean value of total serum prote
in (P <0.05), and a significant increase in the mean values of bilirub
in (P <0.05) in group 1 compared to groups 2 and 3. A significant elev
ation in the mean value of aspartate aminotransaminase, gamma-glutamyl
transferase and creatine phosphokinase and a substantial elevation in
the mean value of alkaline phosphatase was also observed in group 1 co
mpared to groups 2 and 3. Postmortem examination of the dead horses sh
owed that the animals had icterus, hepatomegaly and full urinary bladd
er with deep-red urine. Histopathological examination of the liver sho
wed massive centrilobular degeneration and necrosis. The bile canalicu
li and bile ducts were prominent and plugged with dark-brown to canary
-coloured bile pigments. The lungs had congestion, oedema, and thrombo
sis of pulmonary veins. Our results suggest that the horses suffered f
rom B. equi with clinical manifestation following exercise. The clinic
al, haematological and pathological findings indicate that the animals
suffered from haemolytic anaemia which responded to imidocarb therapy
.