Q: I have a 24-year-old mule. He gets grass hay, crimped oats, and an apple every day. What else should I be giving him as far as vitamins or other nutrients to keep him healthy?

A:  Mules often live well into their 30s and 40s, so it is good you are evaluating his feeding program to help make sure he stays healthy into his golden years. Giving specific diet recommendations is difficult without knowing his current activity level, how much hay and oats he is eating, and his body condition. These are some general guidelines to consider and talk about with your veterinarian to determine the best nutritional support for him going forward.

In general, mules are more efficient with calories and protein than horses of a similar weight, age, and activity level. This means maintaining a moderate and healthy body condition can be more challenging because free-choice hay or pasture often provides more calories than they need, which can lead to obesity and related health issues. I would encourage you to work with your veterinarian to evaluate your mule’s current body condition and general health status. 

Good-quality grass hay is a good base for a mule’s diet, provided he can still effectively chew and digest hay. Weigh your hay to be sure he is eating between 1.2 and 2.0 pounds of hay per 100 pounds of body weight daily. If he is an easy keeper and tends to be overweight, feed toward the low end of the range, but if your mule is a harder keeper or your hay quality is not great, then feed toward the higher end of the range. 

While your mule might enjoy the oats, crimped oats and grass hay don’t provide a complete, balanced diet. I would suggest replacing or supplementing the oats with a ration balancer or a balanced horse mineral to better fortify his diet. Ration balancers provide concentrated, balanced fortification in very low feeding rates. A good ration balancer would provide essential amino acids, vitamins, and minerals in a palatable pellet that most horses and mules happily eat. A horse mineral supplement will generally provide essential minerals and might contain some vitamins, providing fortification missing in the current diet.  With some mineral supplements, achieving consistent intake can be challenging. Keep in mind that trace mineral salt blocks are mostly salt with very small amounts of trace minerals. They lack microminerals such as calcium and phosphorus and will not adequately fortify a hay and oat diet. Instead, choose a ration balancer or completely balanced horse mineral that contains significantly more minerals than salt, and also provide free-choice salt. 

An apple a day as a treat is perfectly fine if your mule is not exhibiting signs of sensitivity to dietary starch and sugars and you are sure he adequately chews and does not choke on a large piece of apple. Your veterinarian can help you determine this. 

Your mule has lived a good, long 24 years so far, and with good nutrition and health care, he could be with you for many more!