I have a 26 year old TWH that has chronic diarrhea. He had vet work done last year, when it first started, with his blood work coming back normal, fecal exam okay and teeth are okay. No feed or hay change. Actually, his stool will be somewhat normal, not firm apples but has some substance to them, for most of the time then about once or twice a month it gets loose to the point of liquid. I had him on ProBalance during some of this time period but it did not seem to affect his stool. He is now on Stomach Smoother but still having the same results as with ProBalance. His coat is shiny, he eats all his grain and most of his coastal hay (his preferred hay for 23 years) and is still very active. His weight is pretty much staying the same the last year. GB

Dear GB,

I have received a rash of questions about diarrhea this week. The answer is pretty much the same for all of them. (Aren’t you glad I didn’t include a picture with this entry?)

Diarrhea is one of those conditions that differs from horse to horse. Because what works for one doesn’t always work for another, you just have to start somewhere, keep a good journal, and try different treatments until something works.

You’ve started in the right place: with your veterinarian. That is, ruling out some of the more common causes through a complete physical examination, blood work and fecal exam. Some uncommon causes of chronic diarrhea require particular tests of blood, feces and even GI tissues; you may have to specifically ask your vet to run these additional tests.

When experimenting with treatments, I recommend keeping a record of everything you try and sharing this “diarrhea diary” with your vet. Before you try anything though, I strongly encourage you to deworm your horse (no matter the result of the fecal) with Panacur PowerPac (if he’s not debilitated). Then give a product with ivermectin and praziquantel to ensure complete coverage of all internal worm species.

Next either try adding products to his diet or changing his diet, but not both at the same time, because then you won’t know which treatment worked! Since your horse has been eating coastal hay, you could switch him to another kind of grass hay or to alfalfa hay. You could also try changing his grain or replacing it altogether with a multi-vitamin/mineral supplement or ration balancer. Remember to make any diet changes slowly, over a two-week period, so your horse doesn’t develop additional problems like colic or laminitis.

Here is a list of products to try to see if they help. Give them one at a time, with your vet’s advice, and for at least 30 days:

• Probiotics, prebiotics, or yeast – to reinoculate and feed the “good bugs”
• Kaopectate and Pepto-Bismol – coat, soothe, relieve!
• Psyllium – in case the diarrhea is caused by inflammation from sand
• Daily dewormer – to prevent gut wall damage from parasites
• Natural anti-inflammatories – MSM or DMG are good choices to quiet a gut
• Digestive enzymes – like those found in Ultra-Elite Digest or Digest-It
• Hindgut buffer – for example EquiShure
• Digestive support – products with L-glutamine, Licorice, Oat fiber and oil
• Plant extracts – like those in APF, to normalize the body’s systems

If none of these over-the-counter treatments work, you may have to go back to your vet and start trying prescription products. Here are a few that have worked for some horses:

• Rheaform – a prescription product that reduces motility in the colon
• Opiates – prescription narcotics related to morphine
• Steroids – prescription immune suppressants
• Antihistamines – prescription products that may work best with steroids
• Antibiotics – prescription only since some antibiotics can worsen the situation!
• Lomotil - prescription anti-diarrhea medication
• Imodium – over-the-counter anti-diarrhea medication

Unfortunately, it’s not uncommon for a treatment to work for a few weeks or months then the horse’s stool gets sloppy again. And some horses never improve, struggling with chronic diarrhea the rest of their lives. Just be patient and thorough and hope for the best!

My 6 year old Paint mare has recently been diagnosed with an ulcer. They recommended 14 days of GastroGuard. I see that most of the studies have been done on 30 days of treatment. Do you usually treat for 14 days or longer in your practice? Also is there a supplement you recommend for horses with ulcers?  Thank you. Regards, LB

Dear L.B.,

You are correct--studies on the effectiveness of omeprazole, the active ingredient in GastroGard, have used approximately one month as the treatment interval. However, these horses’ stomachs were “scoped” on a weekly basis during treatment and it was found that some horses’ ulcers had healed by day 14.  It sounds as if, based on this research and your mare's original diagnosis, your veterinarian feels 14 days will be an adequate treatment time for her. 

More importantly, the research also showed that once treatment stopped, the ulcers came right back. That means you have to do more than just treat the existing ulcers, you have to create an environment in the stomach that makes it hard for ulcers to form.

There are three ways to do this: 1) give the preventive dose of omeprazole, either by using less GastroGard or by switching to the company’s non-prescription product, UlcerGard, 2) select a supplement designed to support a healthy stomach and 3) change the way you feed and manage your horse. There are pros and cons to each of these, so talk to your veterinarian about which strategy(s) might work best for you.

Omeprazole works by stopping acid production by the cells of the stomach. Supplements work in a variety of ways depending on the active ingredients. One of my favorite ingredients to promote long-term stomach health is licorice, one of the most widely used herbs in both Western and Chinese medicine. Other natural ingredients with research supporting their use include pectin and lecithin, the amino acid L-glutamine, polar lipids and beta glucan, and extracts from the plant Aralia elata. Some ulcer supplements simply contain ingredients to buffer stomach acid, like aluminum or magnesium hydroxide.

Finally, here are some diet and management tips to reduce the risk of ulcers in your horse:

• Provide pasture turnout--this is the best method of preventing ulcers!
• Provide constant access to hay—keeping hay in front of your horse is next best
• Provide hay frequently—if free-choice hay is not an option, feeding it four to six times a day is an acceptable substitute
• Use alfalfa hay—the protein and calcium in hay help reduce stomach acid
• Limit fasting periods—keeping food in the stomach at all times protects it from acid which causes ulcers
• Limit grain feeding—sweet feeds especially lead to heavy acid production
• Provide “down time”—heavy exercise is a risk factor for ulcers so include less intense work days and even rest days in your training and showing plan
• Reduce stress—allow social interaction with other horses and keep the feed, turnout, and exercise schedule as regular as possible
• Limit NSAIDS—anti-inflammatories like phenylbutazone have been linked to ulcers, so give the smallest amount necessary for the shortest time possible.