KEEPING WATER BELLY AWAY: HOW AMMONIUM CHLORIDE PROTECTS YOUR SHEEP

Nathalia Pamplona Barboza
12 minutes ago
3 min read

By Nathalia Pamplona Barboza, Ruminant Productivity Consultant

UMMER 2026

Urinary calculi (also called “water belly” or stones) involves the formation of phosphate-based stones in the urinary tract, which prevent urine flow. Left untreated, these blockages can cause the bladder to rupture and result in death. Young wethers are particularly prone to the condition.

This problem is most common when animals are on cereal-based rations that are high in phosphorus and low in calcium, a mineral imbalance that favours the formation of phosphate-based stones in the urinary tract. Once these blockages occur, they are painful, costly, and often fatal.

One of the simplest and most effective ways to prevent the problem is to correct the calcium to phosphorus ratio and include a small amount of ammonium chloride in the ration.

How It Works

Ammonium chloride works by slightly acidifying the urine, which prevents the formation of phosphate-based stones. It does not dissolve those that already exist. When sheep are on cereal-based diets, their urine tends to become more alkaline, allowing minerals like magnesium, ammonium, and phosphate to crystallise. By lowering urine pH slightly (typically below 7), ammonium chloride creates an environment where these crystals are much less likely to form.

In other words, ammonium chloride helps stop stones from forming before they start.

What the Research Shows

A controlled trial in Brazil (Navarro et al., 2021) tested two levels of ammonium chloride, 200 mg/kg and 500 mg/kg body weight in young rams over 56 days. Sheep on the higher rate maintained a more acidic urine from the second week onward, with no negative effects on feed intake, blood chemistry, or rumen health.

Earlier work in the Journal of Animal Science (Crookshank, 1970) compared several acidifying compounds in feedlot lambs. Only those receiving ammonium chloride remained free of urinary stones, while untreated lambs developed blockages.

Veterinary references like the MSD Manual continue to support these findings, recommending 0.5 to 1.5% ammonium chloride in the total ration as a practical prevention rate for small ruminants on grain-based diets.

How We Use It in TPM Formulations

At TPM, ammonium chloride is included in specific formulations like TPM Flock Boost Feedlot Crumble, at safe and effective levels that support urinary health without affecting palatability or rumen function.

By providing consistent acidification through a balanced crumble, producers can reduce the risk of urinary calculi without the hassle of adding supplements separately. It is one of those quiet but important details that keeps animals thriving through confinement periods.

A Few Reminders for Prevention

Several factors contribute to urinary calculi formation, including grain-based diets with a low calcium to phosphorus ratio, hard water, and reduced water intake. Managing these risks early keeps animals performing at their best.

To reduce the risk of water belly:

Maintain a calcium to phosphorus ratio close to 2:1. Always provide clean, good-quality water and ensure access to adequate roughage to promote saliva flow and mineral balance. Use a balanced mineral supplement designed for grain-fed sheep such as TPM Flock Boost Feedlot Crumble, which provides the right calcium balance, salt level, and ammonium chloride inclusion for consistent urinary health.

Take-Home Message

Ammonium chloride is not new technology, but it remains one of the most reliable tools we have to prevent urinary blockages in confined sheep. By helping maintain a slightly acidic urinary environment, it reduces losses and supports consistent performance across the flock.

If you have any questions, please do not hesitate to talk with one of our TRAC Ruminant Experts on 08 8733 1888 or email us at info@totalresult.com.au.