Urinary Stones (Urolithiasis) in Cattle

Quick answer: Urolithiasis means stones (calculi) form in the urinary tract of cattle and buffalo. In females small stones often pass unnoticed, but in bulls and male calves a stone can block the narrow urethra so the animal strains, dribbles or passes no urine at all — a life-threatening emergency that needs a veterinarian at once, because the bladder or urethra can rupture. Most stones come from an unbalanced ration (too much phosphorus or magnesium, wrong calcium-to-phosphorus ratio) and too little water, so prevention rests on a correct Ca:P ratio of about 2:1, plenty of clean water, added salt to make animals drink more, and a balanced mineral supplement.

What is Urolithiasis (Urinary Stones) in Cattle?

Urinary stones form when minerals in the urine become too concentrated and crystallise, then build up into stones in the kidney, bladder or urethra. The most common types in ruminants are phosphatic (struvite) and, on some diets, calcium- or silica-based stones. Males are at far greater risk than females because their urethra is long and narrow and bends at the sigmoid flexure — a spot where even a small stone can lodge and cause complete blockage.

Warning Signs of a Blocked Animal

Call a vet urgently if you see:

• Straining and stretching as if to urinate, with little or no urine coming out
• Dribbling of urine, sometimes blood-tinged, or crystals around the prepuce hair
• Restlessness, kicking at the belly, treading, tail swishing and grinding of teeth (signs of pain)
• Going off feed, dullness and a swollen, painful belly
• Soft, fluid swelling under the belly or between the hind legs ("water belly") if the urethra has ruptured

A complete blockage is a true emergency. Do not wait or try home remedies — the bladder can burst within a day or two, which is often fatal.

Why Stones Form

Most cases trace back to feeding and water management:

• Unbalanced calcium and phosphorus: heavy grain, bran or cottonseed feeding raises phosphorus and upsets the Ca:P ratio, driving struvite stones.
• High magnesium and phosphate diets and alkaline urine favour stone formation.
• Too little water — especially in cold weather, or with dirty or salty water — concentrates the urine.
• Mineral imbalance and inadequate salt intake, which lowers how much the animal drinks.

First Aid: What to Do

If an animal cannot pass urine, the only safe step is to get a veterinarian immediately — treatment may need a muscle relaxant, catheterisation or surgery, and the vet will decide. While waiting, keep the animal calm, offer clean water, and do not force-feed or give random medicines. Never ignore a straining bull or male calf as "constipation"; a blocked urethra looks similar but is far more dangerous.

How to Prevent Urinary Stones

• Keep the Ca:P ratio near 2:1 in the total ration and avoid over-feeding grain, bran and other high-phosphorus concentrates without balancing calcium.
• Give plenty of clean, palatable water at all times; in winter, make sure water is not too cold so animals keep drinking.
• Add common salt to the ration (as advised) to encourage water intake and dilute the urine.
• Use a balanced, chelated mineral mixture so animals are not driven to over-eat imbalanced feeds. Verymin, a chelated mineral mixture from Cattle Remedies, supplies balanced macro- and micro-minerals to support correct mineral nutrition.
• Ammonium chloride to acidify urine is sometimes advised for at-risk herds — use only under veterinary guidance and dosing.

For related reading, see our guides on choosing the best mineral mixture for cattle, signs of mineral deficiency in cattle, and drinking water quality for dairy cattle.

Frequently Asked Questions

Why do male calves get blocked more than cows?

The male urethra is long, narrow and bends sharply, so a stone that would pass easily in a female lodges and blocks the male. Early castration also narrows the urethra, raising the risk in fattening male calves.

Can urinary stones in cattle be treated without surgery?

If caught very early, a vet may relieve a partial blockage with medication and catheterisation, but a complete obstruction usually needs surgery. The outcome is far better the sooner the vet is involved, which is why the straining stage must never be ignored.

What feed changes help prevent stones?

Balance calcium and phosphorus to about 2:1, avoid excess grain and bran, ensure constant clean water, add salt to boost drinking, and provide a balanced mineral mixture. Sudden ration changes and dehydration are the biggest triggers to avoid.

A bull or male calf that is straining and not passing urine is a veterinary emergency. Contact your veterinarian immediately rather than waiting overnight.

References: Merck Veterinary Manual — Urolithiasis in Ruminants; National Center for Biotechnology Information (PMC) — urolithiasis in bovines. This article is general educational guidance for Indian dairy and livestock farmers and does not replace advice from a qualified veterinarian.

By Cattle Remedies (MAKAMS) — Makams Industries Pvt. Ltd.