Question

I have a 22-year-old Arabian mare (14.3 hands; 960 lb or 435 kg) that has Cushing’s. She doesn’t work hard, trotting on a longe line for 20 minutes or so a couple of times a week. Her basic diet includes scant pasture, 16 lb (7.2 kg) of timothy hay, 1 lb (0.45 kg) of ration balancer, and 1 cup of a senior feed to help mix in her supplements. Her supplements include cinnamon, ground flaxseed, chaste tree, probiotics, psyllium, and two digestive products. She also receives pergolide for Cushing’s. I’ve battled loose manure with her for many years, but it seems to be worsening as she ages. Would adding pumpkin or charcoal help her; would either interfere with her medicine?

Answer

Cushing’s may be a factor in your mare’s digestive problems. Horses with Cushing’s are susceptible to weight fluctuations, poor nutrient absorption, increased or decreased appetite, and changes in water consumption. Increased water consumption would more likely result in excess urination.

Since it was not mentioned, I assume her teeth are in good shape and able to successfully process long-stem forage. If this is not the case, it is possible poor chewing of long-stem hay is contributing to her digestive problems. Use of alternative forage sources such as hay cubes, hay pellets, or beet pulp should be considered for horses with dental problems. Another thing to note about hay is that changing hay can affect sensitive horses by disrupting the microbial population of the hindgut. If you get hay from different cuttings often, it is good practice to take a few days to mix the new hay in with the old to allow time for adjustment.

My first suggestion before making more diet changes is to stabilize the hindgut environment (pH) with a specialized hindgut supplement. EquiShure is a time-released hindgut buffer, initially formulated to combat hindgut acidosis, which is frequently used in cases of digestive upset with loose manure. EquiShure is a protected form of sodium bicarbonate that reaches the hindgut to neutralize excess acid, which in turn helps to maintain a more neutral environment. Stabilizing the environment in the hindgut can support and rebalance the microbial population.

The only other recommendation I have is replacing flax with a marine-derived source of omega-3s, such as EO•3. Flax offers a source of omega-3s, known as alpha-linolenic acid (ALA), which requires the conversion of ALA to DHA and EPA to be most beneficial. Research has found that horses have a limited capacity to complete this conversion process. In order to avoid the conversion completely, we recommend feeding a direct source of DHA and EPA with fish oil, like EO•3.

Benefits of EO•3 include the positive effects on glucose tolerance and insulin sensitivity, which is ideal for metabolic horses. Additionally, the anti-inflammatory properties of DHA and EPA omega-3s have shown improvement in horses with various allergy problems. EO•3 is high-quality, deodorized, single-source fish oil supplement that would be optimal for your mare.

Feeding psyllium daily for longer periods of time is not a problem but may not be necessary at this time. Some veterinarians recommend adding psyllium (2 oz/day) as a daily supplement in colitis cases. After a period of time, the bacteria in the colon adapt to ferment psyllium fiber. This fermentation results in the production of butyric acid that is used for energy by the cells of the colon, ultimately promoting repair and helping to counteract inflammation. Psyllium will not cause any problems or reduce the efficacy or action of other supplements. If you see improvement after feeding psyllium, you can continue to use it, but if no noticeable changes occur it is not necessary to continue.

Although pumpkin is often recommended as a supplement for companion animals (cats and dogs) with digestive upset, there is no evidence that feeding canned pumpkin would be effective in the horse. I do not have any information on feeding charcoal to horses with loose or inconsistent manure.

Other articles you might find interesting:

• Is Activated Charcoal Safe for Colicky, Toxic Horses?
• Cushing’s May Affect Digestion in Horses
• Feeding Horses with Pituitary Pars Intermedia Dysfunction

For more information on feeding horses with endocrine problems, download a booklet titled Nutritional Management of Metabolic Disorders.