"The health of the gut is directly influenced by the state of the nervous and endocrine systems, our main barometers for stress." When my newest addition to our small herd, Gwynna — a 40-inch, five-year-old Shetland-Mini cross — arrived last summer, she was overweight, sore, and dehydrated. I quickly discovered that gut health was an issue for her, namely impaction. After our first and thankfully the only emergency call, my vet explained that Miniature horses are prone to impaction colic. Combine this tendency with 30-degree Celsius heat and the stress of a new space, herd, and hay, and she was a prime candidate for problems.