Urolithiasis in cattle, sheep and goat

Prepared by-Dr. Babul R PaulM-5736

Introduction Urolithiasis is common as a subclinical

disorder among ruminants

It considered primarily a nutritional disease

When ration is composed primarily of grain

Mortality is high in case of urethral obstruction

As a result, prevention is important to limit

loses from urolithiasis

UrolithiasisUrolithiasis is the formation of stones

(uroliths) in the urinary tract. It is most commonly seen in castrated male

common sites -1. Cattle:- distal aspect of the

sigmoid flexure 2. sheep and goats:- the sigmoid

flexure and urethral process

Common site of stone formation

Fig:- common site of stone formation in Bull

Sigmoid flexure

Urethral process

Fig:- common site of stone formation in Buck

Etiology Urine is highly saturated Solution of

minerals

Urinary calculi form when inorganic and organic urinary solutes precipitate out of solution.

Calculi form by a gradual accumulation of precipitate around “nidus” (an organic matrix of dead cell) and stone grow in size.

Factors contribute to urolithiasis

1) Those favor the development of

nidus

2) Those that facilitate precipitation

of solute

3) Those that favor concretion by

cementing precipitated salt

Nidus formationLocal infection in urinary tractVitamin A deficiencyEstrogen administration all these causes excessive epithelial

desquamation

Precipitation of solutesExcessive intake of minerals:- Diet containing high concentrate Highly mineralized waterAnimal drinking less water- concentrated urinepH of urine- phosphate & carbonate calculi- alkaline

urine.

Factor favoring concretionMucoprotein – mucopolysaccharides

fraction It act as a cementing agent and favor

the formation of calculi when precipitates are present

The mucoprotein content is increased by heavy concentrate low roughage ration.

Types of uroliths

Phosphatic calculi: - Ruminants consuming ration high in

phosphorus (grain-based rations) typically develop –

Struvite- magnesium ammonium phosphate hexahydrate

Apatite – calcium phosphate

Pelleting of ration as been associated with an increase in Phosphatic calculi

Calcium based calculiCalcium carbonate-Calcium oxalate- common in small ruminant grazing lush, rapidly

growing clover pasture or being fed alfalfa hay. Ingestion of plants high in oxalic acid content can

be risk factor for formation of calcium carbonate calculi

These forages are rich in calcium and low in P & Mg and have a high oxalate content.

Calcium carbonate calculi

Calcium oxalate

Silica urolithswhereas ruminants grazing on

silica-rich soil are predisposed to form silica uroliths.

Risk factor for obstructive urolithiasisSize of individual calculi- often the

obstruction is caused by one stone

Amount of calculus material- aggregation of many small calculi also can cause obstruction

Diameter of urethra- small diameter of urethra in castrated animal

Pathogenesis :-Calculi may be present in kidneys, ureters,

bladder, and urethraMajor clinical manifestation is urethral

obstructionRupture of urethra or bladder occur within

2-3 days if the obstruction is not relieved and the animal dies of uremia or secondary bacterial infection

Smooth, spherical calculus- rupture of bladder

Irregularly shaped stone- rupture of urethra

Clinical finding Stranguria - passage only few drops of

blood stain urineAbdominal pain with kicking at the

bellyTreading with the hind feetSwishing of tailvocalization (especially goats)palpable bladder distention

abdominal palpation in small ruminants

rectal palpation in large ruminants

A heavy precipitate of crystal is often visible on preputial hair

Sequelae to untreated obstructionDiffuse swelling of subcutaneous

tissue of ventral body wall

Medical Treatment Phenothiazine

derivative(aminopromazine 0.7 mg/kg)

Instillation of acetic acid 30-200 ml and hemiacidrin solution through cystotomy catheter

Surgical managementamputation of the urethral

process (small ruminants)urethral catheterization /

retrograde flushingperineal urethrostomyischial urethrostomy cystostomy

Amputation of the urethral process

Perineal urethrostomy

Prevention Adequate balance of Ca and P

(2:1)Increase water intakeNacl supplementation helps to

prevent urolithiasis.Feeding of ammonium chloride @

45g to cattle and 10g to sheep,goat/day)

Vit –A

References Veterinary medicine- A textbook

of the diseases of cattle, horse, sheep, pig and goats

- O.M. Radostits - Clive C Gay - Kenneth W Hinchcliff - Peter D Constable

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