Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 9
Clinical Examination of the
Urinary System
Introduction
Effective function of the urinary system is essential to
maintain good health and homeostasis in cattle. The
incidence of diagnosed urinary system disease in
cattle is quite low. Diseases such as pyelonephritis
are specific to the urinary system. The system can
also be damaged by generalised disease conditions
such as septicaemia and by exposure to toxic substances
including some heavy metals. It is also
interdependent on other body systems and may
malfunction as a result of the failure of these systems.
Malfunction of the urinary system
Malfunction may be prerenal, renal or postrenal. Circulatory
failure (a prerenal problem) through heart
disease or dehydration can have an adverse effect on
renal function. Kidney damage though diseases such
as pyelonephritis may severely compromise renal
function. Inflammation of the bladder (cystitis) with
the production of abnormal urine is an example of
postrenal urinary disease. The effects of renal disease
on other body systems can be serious. Compromise
of renal function can result in disturbances of fluid
balance and the accumulation in the body of substances,
such as urea, which are normally excreted
through the kidneys. The accumulation of these substances
in the body can lead to reduced activity or
malfunction of many body systems. Uraemia may
give rise to clinical signs such as diarrhoea or neurological
disturbance that do not appear to be directly
related to the urinary system. The genital system
in both sexes is closely related anatomically to the
urinary system and concurrently involved with it in
some diseases.
Passage of urine
The passage of urine is the main external sign of renal
function. Increase or decrease in the frequency of
urination, difficulty in urination and in the quantity
of urine produced can all suggest malfunction of the
urinary system.
Discolouration of urine
This may be an indication of prerenal, renal and
postrenal diseases. Specific colour changes are discussed
under urinalysis below. Urinalysis may reveal
the presence of substances such as ketone bodies
which indicate metabolic disease, but which do not
cause discolouration of the urine.
Appraisal
Appraisal of the urinary system must include a careful
clinical examination of the whole animal which
takes into account its wide-ranging influence in the
body.
Applied anatomy
Kidneys
The left kidney lies beneath the 3rd to 5th lumbar vertebrae,
suspended in a fold of mesentery. It is pushed
towards the midline or to the right of the midline by
the dorsal wall of the distended rumen (Fig. 9.1). The
right kidney lies beneath the 12th thoracic to the 3rd
lumbar vertebrae and is immediately in front of the
left kidney. Both kidneys are lobulated and are not
normally palpable through the body wall. The caudal
pole of the left kidney is palpable, and some gross
abnormalities may be detected on rectal examination.
Further evaluation of this part of the kidney is
possible using ultrasonography per rectum. A scan
through the right abdominal wall of the anterior pole
of the right kidney is also possible where it lies in a
notch on the caudal border of the liver.
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