As autumn arrives, the number of older horses who get an impaction starts to rise. There are several reasons, some seasonal and some related to aging. Failing pastures is a primary contributing cause.
Grass is ideal for the older horse, being easier to chew, easier to digest and high in water (about 70 to 75%, compared to 10% or so for hay). When switched to hay, the older horse often will not, or cannot, chew it as efficiently as it should be, making the job of digestion much more difficult. The higher fiber content of hays also makes it less digestible, with more being presented to the large intestine. Processing this load requires lots of water, which is also lacking in the hay.
Just when they need it the most because of dietary changes, water consumption will often fall off. Some older horses do not drink enough because of tooth pain. This is one cause you can eliminate by routinely scheduling your dental care for late summer or early fall.
Another factor may be lameness/stiffness. If the horse finds himself at one end of the pasture with the water at the other, he may choose to ignore his body’s urges to drink if he is uncomfortable moving. Inadequate, dirty or too cold water are also causes of horses not drinking enough water. The horse who is not taking in enough salt (one to two ounces per day) will also have a decreased desire to drink.
The solution to keeping things moving is a game plan for prevention.
• Get dental attention early every fall.
• Be sure water containers are kept clean and full. Position them close to where you feed hay as the horse will usually have the urge to drink during and right after eating hay.
• Keep lameness under control.
• Use the highest quality hay you can find, avoiding large, tough stems.
• Use free-choice, loose salt instead of blocks. Monitor intake. If not sufficient, add 1/2 to 1 ounce to each grain feeding.
• Consider routine use of a probiotic product (our favorite is Ration Plus 800/728-4667) to support normal intestinal function.
• Warm, wet mashes do help and are usually more appetizing than soaked pellets or grains. We suggest a 50-50 mix of wheat bran and beet pulp, which has a balanced mineral profile. Feed daily or several times a week.
Frost, too, can be something to consider. Frosty grass can cause mild-to-moderate digestive upset in some horses, ranging from bloating to actual abdominal pain. The mechanism for this reaction is unclear. It appears to be more a problem for horses turned out only part of the day, rather than all day, probably because they eat more of it than their grass-satiated cousins. Allowing the frost to melt and grass to dry before turnout reduces the chance of a problem.