As equine care has evolved, the proportion of senior horses—those 16 or older—within the population has grown. While transitioning your horse from a successful performance career to a well-deserved retirement can be straightforward and satisfying, medical decision-making can begin to feel more complicated during this stage. In two large studies gastrointestinal (GI) disease was the most common reason for admission to a referral hospital, with colic being the major cause.
Colic is stressful for any owner, especially when trying to decide whether to send a horse to colic surgery—a decision that can become more complex as your horse ages. To help you with this difficult choice, here are considerations to discuss with your veterinarian.
Colic falls into many categories. Here I’ll focus on small intestine vs. large intestine and strangulating (when something obstructs the blood supply to the tissue) vs. nonstrangulating. Of these distinctions, geriatric horses are at increased risk of a strangulating lesion of the small intestine (Krista et al., 2009). This is because geriatric horses are more likely to develop strangulating lipomas, which are essentially balls of fat with a stalk that ensnares a piece of the GI tract, than young adult horses. Unfortunately, horses with small intestine lesions have lower rates of survival to hospital discharge than those with large intestine lesions.
In one study, however, Southwood et al. found no significant difference between short-term survival rates of surgically managed geriatric and adult horses with small intestine strangulations. They did note that upon adding a subcategory of horses ages 20 or older, those surgically managed cases had lower short-term survival than the adult horses.
It appears that while geriatric patients are at higher risk of having a colic type with a more guarded prognosis, if taken to surgery they typically have similar short-term survival rates as adult horses undergoing surgery for the same lesion type.
Anesthetizing any equine patient comes with risk. The size of horses, necessity for them to stand following the procedure, and critical status of some colic patients are just a few of the factors that can translate to equine anesthesia difficulties. In a 2020 study of 1,161 equine anesthesia cases Laurenza et al. found increasing age was a major risk factor for complications and/or mortality. Of those, neuromuscular, respiratory, and cardiovascular complications were associated with increasing age. Understanding the risk of anesthesia is prudent for any owner of a colic patient; however, you might want to discuss with your veterinarian any major contraindications he or she might expect with your horse.
A surgical colic patient’s journey to a successful hospital discharge does not occur as soon as he or she is standing safely in recovery. The postoperative period is critical. Again, colicking geriatric patients are more likely to have strangulating lesions of the small intestine. These lesions are also associated with a postoperative complication known as reflux, where GI fluid accumulates and, instead of being expelled through reabsorption and defecation, fills the stomach and must be removed by nasogastric intubation.
In addition, a common disorder of geriatric horses is pituitary pars intermedia dysfunction (PPID, formerly equine Cushing’s disease). The alterations in PPID patients’ inflammatory and immune responses might create difficulties in the postoperative healing period. Therefore, it is important to understand that geriatric surgical colic patients might require more supportive care postoperatively.
The financial burden of colic surgery is a reality for most horse owners, because the associated costs have increased (Blikslager et al., 2020). While insurance policies cover a portion of the equine population, an owner might be less likely to insure a geriatric horse. In addition, strangulating lesions of the small intestine have been associated with higher expenses compared to those for large intestine nonstrangulating lesions. The more intensive postoperative support small intestine lesions sometimes need can significantly impact total cost.
While each case differs, geriatric horses can respond as well to colic surgery as adult horses with similar lesions. As with surgical colic of any aged horse, discuss the lesion type, possible anesthetic and postoperative complications, and financial impact with your veterinarian.