Because dogs drink from puddles, and horses drink from algae-filled ponds or scummy water troughs doesn’t mean it’s good for them, or won’t hurt them. At best, poor-quality water can result in the horse not drinking as much as he should, risking colic, dehydration and overheating. At worst, it can have negative effects on health. If your horse isn’t drinking “city” water or well water that’s been tested and treated for human consumption, you could be asking for trouble.
• Chemical contamination: Agricultural pesticides, herbicides and fertilizers produced from industrial wastes are carried into the ground-water system, streams and ponds with rain, easily making it into wells and ponds.
• Nitrates: “Organic” fertilizers (manure) can be just as dangerous as chemical because of high levels of nitrogen leading to high toxic nitrate levels in both the water draining those fields and, with heavy applications, also the plants growing on them. Pregnant mares and foals are especially susceptible (abortion, anemia), but even moderate levels of contamination can cause thyroid problems.
• Minerals: A variety of both nutritionally important and toxic minerals can be in your horse’s water. Minerals dissolved in water are approximately 10 times more bioavailable than those in solid foods. Water with a high-mineral content, regardless of the type(s) of minerals, can suppress drinking. High levels of nutritionally important minerals, like calcium, can throw off the mineral balance in the overall diet.
• Algae: Some types of algae are highly toxic.
• Bacteria: Bacteria rapidly proliferate in water that has any organic matter in it (food, feces, rotting vegetation). Water doesn’t need to be sterile for a horse to consume it, but the proliferation of potentially harmful bacteria in high numbers can overwhelm the animal’s natural defenses.
• pH: pH is the measure of acidity or alkalinity in the water. Very alkaline water can cause digestive upset, diarrhea, reduced eating and drinking. Acidic water is better tolerated, but the bioavailability of toxic minerals skyrockets in acid water.
• Salinity: In some areas, a high dissolved-mineral-salt content in the water is a problem. These may be chlorides, sulfates, carbonates or other forms. Not all cause a problem, but high levels of salt may cause dehydration. Some can be toxic, like fluorides.
What to Do'
Have your horse’s water supply tested for pH, nitrates, total solids, bacteria, hardness and salinity by a human water testing service. In some areas, the local health department, water department or Environmental Protection Agency (EPA) may offer free testing of well water. Some commerical water-treatment companies offer limited free testing. If you can’t locate someone to test for free, basic testing as above typically runs about $40 to $70.
Contact your local water authority for information regarding common chemical and mineral contaminants in your area. If any toxic minerals are a concern, test for these as well, or consider just investing in a hose filter that will remove toxic metals and many harmful chemicals.
For problems with pH, you can adjust acidic waters up by adding baking soda, or lower pH of alkaline waters with vinegar, both safe for horses.
To determine how much to add, buy some pH test strips, take a gallon of your horse’s water and add the vinegar or baking soda in small amounts, mixing well, until the water tests between 6.5 and 8. Multiply the amount per gallon needed by how many gallons are in your buckets or troughs and add this each time you clean and refill the tank.
For algae problems in natural water sources or troughs, use copper sulfate at a rate of ?? teaspoon per 300 gallons of water.
Always clean water and feed buckets, troughs and automatic waterers regularly. Don’t allow scum to build up on the sides. Remove leaves, bugs, food, manure, etc. as soon as you see it.
Water left unchanged for more than three days may also be breeding mosquitoes. Plain salt or baking soda is abrasive enough for cleaning, without risk of any harmful or distasteful residue.
Also With This Article
”Livestock Water Quality Standards”