Veterinary Medicine

1. Dr. Ajith Y. MVSc PhD
Assistant Professor
TeachingVeterinary ClinicalComplex, COVAS, Mannuthy
Department of VeterinaryClinicalMedicine, Ethics and Jurisprudence
KeralaVeterinaryandAnimal Sciences University, Pookode

2. • It is the ‘Formation and aggregation of microscopic/
macroscopic mineral crystals or amorphous deposits
of various salts in ANY part of the urinary tract’.
• Composition:
– Organicmatrix/nidus(2-10%)
– Inorganic/mineral(90-98%)
• Obstruction is common in castrated males (length and
diameter of urethra, sigmoid flexure, urethral process in bucks)
• In Dalmation dogs, ammonium urate crystals are
common due to inability to convert urate to allantoin.
• Ruminants kept in intensive concentrate feeding.

3. • Increased organic nidus/matrix: Desquamated cells
and debris due to infection/inflammation, increased
cortisol, estrogen (phyto or additive), Vit A deficiency.
• Factors facilitating precipitation: More time causing
urinary stasis, altered pH, lack of protective colloids,
Side effect of sulphonamide, Vit C, estrogen, steroids…
• High concentration of solutes: Dietary intake (hard
water, silica, Ca, Mg, PO4), Dehydration in summer,
inadequate water intake in winter. Oral NaCl prevents
Silicate formation.

4. Crystal Urine PH Color Forms
Uric acid Acidic Yellow Rhombic or irregular plates,
prisms, rosettes; or oval with
pointed end
Amorphous
urates
Acidic Pink
Yellow
Granules
Calcium oxalate Acidic/
neutral/al
kaline
Colorless Octahedral or envelope (small
squares crossed by 2
intersecting diagonal lines),
dumbbell
Hippuric acid Acidic/
neutral/sli
ghtly
alkaline
Colorless Prisms, plates or needles

5. Crystal Urine PH Color Forms
Calcium
carbonate
Alkaline Colorless Spheres, ovals and dumbbells
‘Oxalate toxicity in ruminants’
Triple phosphate
(struvite,
magnesium
ammonium
phosphate)
Acidic/
neutral/sli
ghtly
alkaline
Colorless Prisms with oblique ends
(coffin-lids), feathery
‘Most common in Dogs’
Amorphous
phosphates
Alkaline Colorless Granules in masses
Ammonium
urate
Alkaline Yellow Spheres, often covered with
spicules, dumb-bells, or
sheaves of neeedles

6. Crystal Urine PH Color Forms
Bilirubin
(hematoiddin
)
Acidic Yellow/
dark red
Needles, plates or
granules
Leucine Acidic Yellow Spheres with radial and
concentric striations
Tyrosine Acidic Colorless Fine needles usually
arranged in sheaves with
a constriction at middle
Cysteine Acidic Colorless Hexagonal plates

7. • Non-symptomatic unless local inflammation or obstruction.
• Pain on palpation and signs of abdominal pain (crying).
• Pollakiuria, dysuria, stranguria (as in cystitis)
• Urinary incontinence, matting of hair near external urethra.
• Vomiting due to azotemia.
• Subcutaneous accumulation of urine in umbilicus, prepuce
and perineal region - Bladder/Urethral rupture ? (Aspirate)
• Hematuria --> Location of stone
– Blood in initial part of stream in lower tract.
– Blood mixed urine or in last part in upper tract.

8. • Abdominal/ Per-rectal palpation: Urocystoliths……
(Often multiple locations……so must go for radiography)
• Radiography: Plain --> Most stones are radio-opaque….
Urate/Cystine may be radiolucent. So, go for contrast.
• Urinalysis: Demonstrate crystals
• Serum biochemistry: Azotemia (BUN, Creatinine),
hyperkalemia, Ca, P, Mg???
• Ultrasonography
• Cystoscopy
• Peritoneal fluid aspiration: creatinine levels?....

10. • FIRST Relieve pain and pressure due to obstruction.
• Alteration of pH:
– If alkaline urine (Struvite, oxalate etc)--> Acidification needed.
– If acidic urine (Urate, Cystine etc) --> Alkalinization needed.
– Dietary management - Urea formation controlled.
• Infection control: Like in cystitis…
• Treatment of post-renal azotemia
- Diuretics?????, Dextrose, antihypertensive, Fluid
• Solubilizing urolith: Herbal products (Cystona)
• Retrograde urohydropropulsion (RISK???)
• Cystostomy, Cystotomy, Urethrostomy & Lithotripsy

11. ajithy@kvasu.ac.in
ajithy123456789@gmail.com
8891981301 (WhatsApp)