We recently saw a rare case of urea toxicity on one of our farms. Thankfully only a few animals were affected, and due to the actions of the farmer there were no deaths.

Urea toxicity is uncommon in Southland. Knowing why it happens, what to do if you spot signs, and how to avoid it, can reduce risk further. 

Typically, toxicity in cattle occurs following incorrect feed storage, contamination of feed troughs, or turning stock out onto pasture recently covered with urea. A toxic dose is only 20g per 50kg of liveweight, so they don’t require a huge amount to begin having issues. 

About 20 minutes after ingestion you’ll start to see signs, including twitching, excess salivation, muscle tremors, collapse and convulsions. Cows will often bloat and struggle to breathe if badly affected. Usually, farmers will find a certain group of animals affected, such as those feeding on a particular section of paddock or recently eating from a feed trough (e.g. in a milking shed). 

If any of these symptoms are noticed, call your vet straight away. The animals on that pasture or with access to that feed trough need to be immediately moved to an uncontaminated area. Make sure they have free access to clean water. 

Drenching affected cattle with 30-40L of water and 3-5L of vinegar can help slow the onset of clinical signs. 

To prevent toxicity, ensure that adequate time and rain has transpired between spreading urea on paddocks, and putting cattle onto them. An even spread of urea over pasture is key, as clumps of urea can take longer to dissolve into the soil. 

It’s also important to check that feed is uncontaminated before giving it to stock and to thoroughly wash out any troughs that contained urea before using them for feeding.

Prevention is easier than treatment when it comes to urea toxicity, but taking prompt action if it does occur can minimise its impact on your herd.