Why did your horse colic? Was the cause dehydration? Stress? Ulcers? Porcupines? That's right—if you’ve got porcupines in your area, your horse could end up in a prickly situation similar to the one an 11-month-old Andalusian filly found herself in: having two colic surgeries after swallowing a porcupine quill.

“We think 'Luta' got it in the hay,” said Stacy Anderson, DVM, PhD candidate at the University of Saskatchewan’s Western College of Veterinary Medicine, in Saskatoon, Canada. “Most horses would be able to sift through their hay well enough to avoid eating a quill. However, this filly was young and so potentially less discerning in her eating habits (as many young horses are).”

Anderson recently published a study describing her experience with the case.

Once in the digestive tract, the quill pierced through the intestines—twice—and then got stuck, Anderson said. After two operations, weeks of hospitalization, and three months of stall rest, the filly was finally freed of the quill and most of its consequences on her digestive system