Studies on the pathology of dicrocoeliasis and fascioliasis in the goat. 3. The histochemistry of mast cells and globule leucocytes

Comparative studies were made on the structure and histochemistry of mast cells and globule leucocytes in dicrocoeliasis and fascioliasis of the goat. Investigations showed that D. dendriticum and F. hepatica infections in the goat produce an increase in the number of hepatic mast cells and frequent occurrence of globule leucocytes in the epithelium of the bile ducts. The only difference between these infections was that globule leucocytes were more frequent in small bile ducts in dicrocoeliasis than in fascioliasis.Histochemical methods showed the presence of sulphomucins in the granules of mast cells, while both neutral mucins and carboxymucins were revealed in the globules of globule leucocytes. The acidity of the mucosubstances could not be shown to result from hyaluronic acid, chondroitin-4 and -6-sulphates, or sialic acid. The globules of globule leucocytes also contained histochemically identifiable highly basic proteins.Keyword: Dicrocoelium dendriticum, Fasciola hepatica, liver, bile ducts, mast cell, globule leucocyte     

Studies on the pathology of dicrocoeliasis and fascioliasis in the goat. I. The histopathology of the liver and bile ducts

Comparative studies were made on the histopathology of the liver and bile ducts in dicrocoeliasis and fascioliasis of the goat. Investigations revealed certain similarities in the nature of the pathological phenomena produced by D. dendriticum and F. hepatica. However, a feature peculiar to fascioliasis was the migratory tracks of immature flukes in the liver parenchyma. Further, the lesions produced by fascioliasis were distinctly more pronounced than those present in dicrocoeliasis.In both parasitic diseases the bile-duct walls showed glandular hyperplasia, increased frequency of goblet cells and globule leucocytes, and extensive fibrosis in the outer layers. The desquamation produced by Dicrocoelium remained superficial whereas Fasciola was capable of causing deep erosions in the walls of the main bile ducts. The bile-duct walls did not become calcified. Increased fibrosis was present in the interlobular areas, too, but only fascioliasis produced extensive disorganisation of the hepatic architecture, due to the scars originating from repaired migratory tracks. The liver parenchymal cells were degenerated, showed decreased glycogen but were increasingly infiltrated by neutral fats.Keyword: Dicrocoelium dendriticum, Fasciola hepatica, liver, bile ducts     

The pathology and pathogenesis of Trypanosoma vivax infection in the goat.

Acute and chronic forms of disease can be distinguished in Trypanosoma vivax infection in the goat. The main difference between the acute and chronic form seems to be the presence of microthrombi in the acute stage of infection; these consist of platelets, trypanosomes, monocytoid cells and some fibrin. This thrombus formation seems directly related to the high parasitaemia in acute trypanosomiasis and may result in ischaemia which could also explain the haemorrhages, the oedema of the lungs and other tissues, and the necrotic changes found in several organs. The anaemia, associated with erythrophagocytosis, haemosiderosis, extramedullary haemopoiesis and hyperactivity of the bone marrow, seemed to be of haemolytic origin. The factors leading to emaciation seemed to be degenerative atrophy of muscular tissue and loss of protein in the urine caused by a possible immune complex glomerulonephritis.     

The clinical pathology of heartwater. II. Studies on cardiac and pulmonary function in 4 calves with experimentally-induced heartwater

Studies to evaluate cardiac and pulmonary function were undertaken in 4 calves suffering from experimentally-induced heartwater. There was a marked variation in the course of the disease. Three of the calves recovered spontaneously after developing clinical signs. These included a rectal temperature in excess of 40 degrees C, anorexia and listlessness but no neurological signs. The remaining calf died 2 days after developing a fever and neurological signs. In the 3 calves that recovered, a mild hypoxemia developed during the acute stage of the disease. Arterial CO2 tension remained within normal limits, but there was a tendency towards an alkalosis. Increases in pulmonary dead space and fluctuations in venous admixture were observed. The calf that died showed similar mild changes in blood gas parameters, despite the presence of a marked reduction in minute volume, and a lung oedema was demonstrated on post-mortem examination. No marked changes in systolic and diastolic blood pressures and in right cardiac intraventricular pressures were observed. Terminally, however, there were marked decreases in stroke volume and cardiac output. These changes were associated with a sharp increase in heart rate. No primary cardiac pathology was observed on clinical and post-mortem examinations.     

Studies on reproduction in the goat. VII. Pregnancy and the development of the foetus and the foetal accessories of the goat

1. A total of 18 goats were ovariohysterectomized at different stages — 26 days to 145 days — of pregnancy.
2. The amniotic fluid increases from about 3.5 ml at 30 days to 600–1,000 ml per foetus at birth.
3. At birth the amount of allantoic fluid is approximately 600–1,100 ml and is to a small extent dependent on the number of foetuses.
4. The length of the foetus is about 1.4 cm at 30 days and 43 cm at 145 days, the lengthwise growth curve from the 30th day and onward being almost linear.
5. Hair follicles are visible around the 60th day and the eyes open between the 130th and 140th day.
6. The average length and weight of the goat kids at birth are 42.06 cm and 2.81 kg respectively.
7. The birth weight and length tend to increase with the increasing age of the dam.
8. The male does not appear to have any influence on the birth weight and length of the offspring.

     

Studies on fascioliasis in four selected sites in Ethiopia

The incidence of fascioliasis was studied in Asela, Awasa, Debre Zeit and Debre Berhan by using 153 experimental sheep divided up into 4 groups designated tracer sheep, Controls I, II and III. Fasciola hepatica was encountered in Debre Berhan, Asela and Awasa, but it was not detected at Debre Zeit. In all areas, it was most frequently recovered after heavy rains. Altitude, soil type, salt content and local crowding of animals in watering sites appear to have influenced the varying degrees of incidence and intensity of infection.