Mare ingests almost 100 pounds of sand and gravel

Ally Sisco, from north of Spokane, is an experienced horse owner who currently cares for eight horses. One morning, she noticed something unusual about Calliope, her 11-year-old Gypsy-Clydesdale: The mare had no interest in her breakfast.

“That was weird for her because she’s definitely into her food,” Sisco recalled. “She was also lying down a lot more than normal. She likes to lay down frequently, but she was lying out flat, which I thought was strange because she only does that when it’s really sunny, and it wasn’t that sunny.¹”

Calliope, an 11-year-old gypsy-Clydesdale, was treated for sand colic at Washington State University (Image courtesy of Washington State University)

Wanting to help Calliope, Sisco administered Banamine, a drug commonly used to treat mild cases of colic and then walked her to help pass whatever was causing her discomfort. After this did not work, Sisco put Calliope in her trailer and took her for a ride, which is a common thing horse owner to do try and ‘get things moving.’

Calliope showed no signs of improvement, so Sisco asked a local veterinarian for advice, and they told her to take her to Washington State University (WSU) immediately. Once they were at WSU, Calliope was diagnosed with a painful and potentially serious condition in horses, sand colic. This condition is caused by the accumulation of sand or gravel in the intestine, which causes irritation, inflammation, or blockage of the digestive tract.¹ According to WSU, their staff sees about 10 to 15 cases of sand colic annually and treat these cases with fluids and supportive care. In severe cases, surgery is required.

For Calliope, her clinicians hoped that supportive care would be enough for her, but after a week of being at the hospital, she was rushed into surgery after she took a turn for the worse. Calliope then developed ventricular tachycardia after being placed under anesthesia. The surgical team stabilized her and then removed around 80% of the gravel and sand before ending the produce to reduce the risk of her being under anesthesia.

“I don’t think anybody really knew just the extent of how much she had in there,” Sisco said. “When they told me it was around 100 pounds, I was so surprised. I’ve been looking all over my property trying to find where she might have gotten into it...I can’t find it anywhere.”

Calliope was able to head home 11 days after her surgery and is now months into her recovery. WSU reported that she is doing well, but will need some follow up imaging done to make sure the other 20% of materials passed.

“This was the first time I have ever taken a horse to WSU. They took great care of her,” Sisco said. “When I visited, she looked clean and shiny, and they even braided her mane. It looked like they were really enjoying her, which was nice.”

Erin Pinnell, DVM, MS, DACVIM (LAIM), warns horse owners to not feed horses directly on the ground to help prevent sand colic, and if a horse is presenting with signs of colic, seek veterinary care early. However, ground feeding is not always the problem, such as in Calliope’s case where she was never fed on the ground, but it can contribute to the problem.

“We want owners to know this is something we see in this region,” concluded Pinell. “If you live in an area with sandy or gravelly soil, talk to your vet about preventative measures, because early intervention really can save a horse’s life.”

To this day, how Calliope was able to ingest this much gravel remains unknown to Sisco and her team at WSU.

Reference

1. Rokyta D. WSU veterinarians remove nearly 100 pounds of sand and gravel from horse’s belly. WSU Insider. Published August 22, 2025. Accessed August 28, 2025. https://news.wsu.edu/news/2025/08/22/wsu-veterinarians-remove-nearly-100-pounds-of-sand-and-gravel-from-horses-belly/