Urinary calculi is a common, deadly, painful, and often preventable disease with a poor long term prognosis. It is mainly a disease of castrated wethers due to potential stunting of growth of the urethra, although bucks and rams are also at risk. UC is far more common in goats than sheep, so take extra precaution in feeding male goats. Female does and ewes are also less commonly affected due to their shorter and wider urethra, which allows for passage of urinary crystals, thus reducing risk of progression to stone formation, as well as reduced risk of obstruction if stones do occur.

Let’s talk calcium and phosphorus, and why too much of either is a bad thing.

Phosphorus: the main culprit

• Most incidents of urinary calculi in goats is due to a diet that is too high in phosphorus. This is mainly sourced in grains such as corn, oats, barley, etc, which is why it’s often advised online to avoid grains and pellets entirely for wethers, however balance is key.
• Phosphorus is essential for energy metabolism, works with calcium to form a strong skeleton, and is vital for formation of soft tissue.

Calcium: the flip side

• A diet that is too high in calcium can also cause urinary calculi in goats by way of Calcium Carbonate and Calcium Oxalate stones.
• Essential for bone health and muscle and nerve function. Increase need for lactating, pregnant, and growing animals.
• Forage legumes like alfalfa and clover are great natural calcium sources. Supplemental calcium is often needed, along with other minerals. This can be offered in formulated commercial feeds, free choice mineral mixes, and/or feed grade limestone to achieve proper ratio.

Both are needed, in moderation

In general, a ratio of 2:1 calcium to phosphorus is recommended for both goats and sheep in their complete daily intake. The type of hay fed, and amount of pasture/forage, will also need to be considered in this ratio. A ratio of up to 7:1 calcium to phosphorus is generally acceptable so always lean towards more calcium.

Further protection

Ammonium chloride, the chemical used to treat active UC, can be given preventatively to goats and sheep in small amounts. It works by lowering urine pH, acidifying the urine, and thereby preventing mineral and stone build up in the urinary tract. It’s generally recommended to give in a “pulse” dosing (for an example: 4 weeks on, 4 weeks off), but some veterinarians will recommend consistent use for higher risk animals. It can be found in some commercial feeds in small percentages. It is also recommended to delay castration when possible, ideally until 6-12 months of age, but at least 10-12 weeks. Ensure drinking water is plentiful, clean, and fresh as adequate hydration is of utmost importance.

Bryer Milling Feeds

All of our feeds at Bryer Milling are formulated with prevention of urinary calculi as a priority. For castrated goats especially: we recommend our Goat Maintenance Feed. Not only is the complete feed balanced at the recommended ratio of calcium to phosphorus, but is also offered in a formulation containing ammonium chloride at a rate of 0.5%. For the purpose of “pulse” dosing as previously discussed, or for those who do not wish to utilize the chemical, we offer the feed both with, and without ammonium chloride.

For your sheep flock we recommend the Sheep Maintenace Feed. Even though urinary calculi is less common in sheep than goats, it’s still crucial to feed consciously. Calcium and phosphorus are balanced at a ~2:1 ratio, and the feed is also offered with or without ammonium chloride.

Sources

• Maryland Small Ruminant Page
• Mississippi State University
• A Greener World
• Michigan State University
• Texas A&M