Page 949 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

924 CHAPTER 7

VetBooks.ir 7.1 7.2

Fig. 7.1 Sterile gloves, sterile urinary catheter, Fig. 7.2 Catheterisation of the urinary bladder in a
sterile ointment or jelly, sterile cup, refractometer male.
and urine test strips are basic equipment required for
aseptic urine collection.

from the distal urethra and the genital tract makes 7.3
interpretation of the results more difficult. The
analysis of an early stream of voided urine can often
distinguish urethral and genital tract diseases from
diseases within the bladder or more proximal in the
urinary system.
Urethral catheterisation is easy to perform in most
horses, with only basic equipment required (Fig. 7.1).
Catheterised samples should be obtained when voided
urine cannot be collected or when samples for bac-
terial culture are required (Figs. 7.2, 7.3). Alpha-2
adrenergic agonists (i.e. xylazine, detomidine) and
exogenous corticosteroid administration cause diure-
sis and glucosuria. Trauma to the urinary tract is
inevitable with catheterisation and will often cause a
mild increase in urine protein levels, red blood cells
(RBCs) and transitional epithelial cells.

Physical and chemical properties of urine Fig. 7.3 Catheterisation of the urinary bladder in a
Equine urine should be pale yellow to deep tan female.
(Fig. 7.4) but exposure of it to air usually causes
the colour to darken. Large numbers of calcium
carbonate crystals and mucus may be present in haemoglobin or myoglobin in the urine. If pigmen-
normal urine, resulting in a highly turbid sample. turia/haematuria of urine is present at the start or at
Discolouration of the urine can be caused by the end of urination, the lesion may be located in the
pigmenturia or haematuria (red to brown urine), urethra or accessory sex glands. Haemoglobinuria,
neither of which should be present in normal urine myoglobinuria or the presence of intact erythrocytes
samples. Pigmenturia is caused by the presence of in the urine yields a positive result on a reagent strip.