126 DISEASES OF CATTLE. 



TUMORS OF THE KIDNEY (HYPERTROPHY OR ATROPHY). 



The kidney may be the seat of cancerous or simple tumors, and it 

 may be unnaturally enlarged or reduced in size, but though there may 

 be signs of urinary disorder the true nature of the disease is seldom 

 manifest until after death. The passing of blood and of large multi- 

 nucleated cells in the urine (to be detected under the microscope) 

 may betray the existence of an ulcerated cancer of the kidney. The 

 presence of cancerous enlargement of (superficial) lymphatic glands 

 may further assist and confirm the decision. 



RETENTION OF URINE. 



Inability to pass urine may come from any one of three condi- 

 tions — first, spasm of the neck of the bladder; second, paralysis of 

 the body of the bladder; third, obstruction of the channel of outlet 

 by a stone (calculus) (see PL XI) or other obstacle. 



In spasm of the neck of the hladder the male animal may stand 

 with the tail slightly raised and making rhythmical contractions of 

 the muscle beneath the anus (accelerator urinte) (see PI. IX, fig. 2), 

 but without jDassing a drop of liquid. In the female the hind legs 

 are extended, widely jjarted, and the back is arched as if to urinate, 

 but the effort is vain. If the oiled hand is introduced into the rectum 

 or Aagina in the early stages of the affection, the bladder may be felt 

 beneath partially filled, but not overdistended with liquid, and its 

 neck or mouth firm and rigid. In the more advanced stages of the 

 affection the organ is felt as a great, tense, elastic bag. extending 

 forward into the abdomen. In this condition the overdistended mus- 

 cular coat of the bladder has lost its power of contraction, so that 

 true paralysis has set in, the muscle closing the mouth of the sac 

 alone retaining its contractile power. 



In paralysis of the hody of the 'bladder attention is rarely drawn to 

 the urinary disorder until the bladder has been distended to full 

 repletion and is almost ready to give way by rupture and to allow 

 the escape of the contained liquid into the abdomen. Overdistention 

 is the most common cause of the paralysis, yet it may occur from in- 

 flammation of the muscular wall of the bladder, or even from injury 

 to the terminal part of the spinal marrow. In this last condition 

 however, the tail is liable to be powerless, and the neck of the blad- 

 der may also be paralyzed, so that the urine dribbles away continu- 

 ously. 



Causes. — Among the causes of spasm of the neck of the bladder 

 may be named the lodgment of small stones or gi-avel, the feedino- on 

 irritant diuretics (see " Bloody urine," p. 117, or " Nephritis," p. 121) 

 the enforced retention of urine while at work or during a painful or 

 difficult parturition. The irritation attendant on inflammation of the 



