I am finding this to be more common than you think. This happens when your horse either passes gas or has a bowel movement and out squirts brown liquid that runs down the legs. The manure can be formed and appear normal. Your horse can have no other symptoms but squirting the fecal liquid.
The cause can be difficult and frustrating to identify. It can be caused from worming or a worm overload, antibiotics, electrolyte imbalance, intestinal flora imbalance, stress, dehydration, heavy metals toxicity, leaky gut, ulcers, digestive disorders, sand in the gut and more.
In order to find something that may clear it you will need to go through a process of elimination to find what works and what does not work for your horse. Before starting, be sure that your horse is only getting grass hay or alfalfa/grass mix. No grains.
This is a list of natural supplements I have tried, some helped and some did not.
Three different Veterinarian's Protocol consisting of probiotics
and other supplements: did not help
Probiotics: helps slow it down
BioSponge by Platinum Performance: did not help
Diagel: worked to clear it but only for 3 to 4 days. Too expensive to maintain
Apple Pectin: did not help
Kaolin Pectin: did not help
Succeed: helps slow it down
Psyllium, granular or pellet form: Did not work
Lecithin granules: Helps slow it down
Oat Bran: Helps slow it down
Quercetin: Did not work
Vitamin C: Did not work
Electrolytes: Worked on and off
DePaolo Excel: Worked on and off
Uckele custom blend minerals based on hair analysis: helps slow it down
DePaolo custom blend minerals based on hair analysis: This works the best.
Depending on what the cause is, some of these items may or may not work for your horse. If none of these supplements help then the cause could very well be an electrolyte deficiency/imbalance and/or a heavy metal toxicity.
It is important that your horses minerals are in the right balance. The best way to find this out is through a hair analysis test. If you have tried all of the above and your horse still has the squirts then I would recommend having a hair analysis done. This will pinpoint the imbalance and can quickly be corrected with a custom mineral blend. I would highly recommend ordering the hair analysis through DePaolo Equine Concepts.
It is one of the most informative test you can do for your horse. Based on the findings of the test, Dr. DePaolo will customize a mineral blend for your horse. Once starting your horse on the custom blend the problem should clear within a week in most cases.
Not only are you clearing the squirts, you are correcting a mineral imbalance and/or heavy metal toxicity which is the most likely cause of the symptom. This is important.