442 DISEASES OF THE BLOOD. 



h3'dro-iiephrosis obtains, which results in atrophic lesions of the kidney, 

 and ma_y finally end fatally. 



The mesenteric lymphatjc glands may hypertrophy, their substance 

 becoming tumefied, presenting small hsemorrhagic centres, and contain- 

 ing eggs. The liver may contain eggs and become somewhat cirrhotic; 

 the eggs accumulate in the branches of the portal veins, or after 

 piercing the walls they lie in the hepatic parenchyma. The lungs 

 may also contain eggs. 



Diagnosis. The diagnosis may easily be made by a microscopic 

 examination of the urine to determine the presence of the egg. 



Prognosis, etc. The seveiity of the disease varies directly with the 

 number of parasites (and hence the number of eggs) in the body. 

 Fortunately, in the majority of cases, the number of parasites is small, 

 though it may increase from repeated infections to 500 or more. In 

 cases of comparatively light infection the disease is reduced to a slight 

 chronic cystitis, with now and then exacerbations, in course of which 

 a slight amount of blood and pus is passed in the urine. The disease 

 may last for years without apparent increase. In the most severe cases 

 death may occur from various causes, rupture of the bladder, ascending 

 pyelo-nephritis, uraemia, albuminuria ; the patient may die in marasmus, 

 being exhausted by the dysentery or the anaemia. 



Bilharziosis is accordingly not such a fatal disease as has sometimes 

 been supposed. 



HEAT STROKE-OVER-EXERTION. 



In oxen and sheep heat stroke is rare as a primary accident, but it is 

 frequently produced by over-exertion resulting from the combined action 

 of the sun's rays, heat, and fatigue due to work or travelling. 



It is commonest during the hottest months of the year in oxen doing 

 hard work or in flocks which have been travelled considerable distances. 

 It may also be seen during cooler seasons as the result of exceptional 

 fatigue. 



The disease results from a general intoxication which reacts most 

 markedly on the cerebro-spinal centres. It is in fact a complex 

 intoxication resulting from failure of the natural excretory organs to 

 perform their function completely, and from excessive central heat 

 acting on the nervous centres. 



Fat animals out of condition are more readily attacked than work- 

 ing animals or sheep reared in the open air. 



The symptoms are very characteristic. Oxen when attacked first 

 of all show extremely rapid respiration and dyspnoea, announcing pro- 

 gressive asphyxia. They move with the nostrils dilated, the eyes 

 prominent and injected, the mouth open and the tongue lolling out. 



