This is much more common than is supposed. Small calculi formed in the
tubuli uriniferi of cattle on dry winter feeding often pass without
recognition, and habitually disappear on rich spring and summer grass.
If retained in the pelvis until increasing size forbids their passage
through the ureter they form pelvic calculi.
If retained in the bladder so that they cannot enter the urethra they
form cystic calculi.
Pelvic calculi or concretions are often (in cattle and swine) mere
scales lying in chalices. They may fill the whole pelvis and send
branching processes into chalices.
_Causes._ They are attributed to phosphaturia, lithæmia or uric acid
diathesis, oxaluria, etc. In cattle they are associated with dry feeding
and are common on all magnesian limestone soils. There are usually
catarrh of the kidney and the presence of bacterial ferments and
colloids (pus, albumen, etc.). (Sharing and Ord.) Calculi or gravel is
preceded by renal catarrh, but this is aggravated by the crystalline
deposit. Bacteria act also in producing NH_{3}O, which instantly
precipitates ammonio-magnesian phosphate. Retention of urine greatly
favors the precipitation.
_Symptoms._ A white or brownish yellow deposit in the last urine
discharged collects on the floor. Cloudy urine. Passage of
crystals—round—or angular. Colic. Lameness in one or both hind limbs.
Arched back. Sensitive loins. Pain paroxysmal. Attempts to urinate.
Little passed but often with drops of blood. Sudden relief when the
calculus enters the bladder.
Retained in the kidney it may cause no suffering in meat producing
animals, but in horses it usually causes stiffness or lameness
especially under violent effort. Also hematuria; blood globules are
found in the deposit when placed under the microscope. There may be
sepsis and specially cloudy offensive urine.
_Diagnosis_: May be confounded with renal tuberculosis, or sarcoma or
oxaluria. Examine for bacillus, small cells, or oxalate of lime or
oxalic acid.
_Prophylaxis._ In the early stages give succulent, watery food,
ensilage, roots, potatoes, spring grass, and water ad libitum.
_Treatment._ Salt may tempt the patient to drink. Nitro-muriatic acid is
a solvent and antiseptic. Or alkalies with salicylate of soda. Also
tonics. Quiet pain by morphia and other anodynes. Use piperazine.
These failing, an operation on the kidney may be considered.