Cookie, like many ponies, was known for being very food motivated. So when the 12-year-old gelding left his evening meal untouched one Sunday in late summer, his owners were concerned and immediately moved him to a paddock near the house to keep an eye on him. Sure enough, within hours Cookie began to look uncomfortable. By midnight he had the classic signs of colic. He was sweating, rolling and agitated. His owners placed an emergency call to his veterinarian, who arrived within a half hour.
The veterinarian found that Cookie had an elevated heart and respiratory rate but his temperature was normal as was his gum color. There were also signs that the gelding was dehydrated: His capillary refill time was slow and his gums felt “tacky.” In addition, the gelding had diminished gut sounds, called borborygmi. Cookie had been on 24-hour turnout, so the last time he had passed manure was unknown, but he hadn’t passed any since he’d been moved to the paddock.
During the exam, the veterinarian noticed a trickle of liquid running from Cookie’s nose. This sometimes indicates choke but the gelding wasn’t showing any of the other signs of the condition, like stretching his neck or making retching noises. A rectal exam didn’t reveal anything concerning. Cookie’s veterinarian had to consider all of these factors in determining the cause of the pony’s digestive upset.
Colic can have many causes, and a veterinarian will often make a preliminary diagnosis based on clinical signs. Here are the possibilities that Cookie’s veterinarian considered.
When gas accumulates in the intestines, spasmodic colic (often referred to as gas colic) can occur. The pain results from the stretching of the intestines. Gas buildup can be caused by fermentation of grass or hay or sudden changes in feed. This type of colic commonly causes observable signs of discomfort, such as rolling or kicking at the stomach, but fever is rare.
This type of digestive upset that stems from the chronic accumulation of sand and dirt in a horse’s intestines—specifically the large colon. It can strike any horse who lives on loose, sandy soil. Horses with sand colic often have elevated heart rates, sweating and diarrhea.
Inflammatory conditions such as enteritis and colitis can lead to painful colic. Often caused by bacterial or viral infection, inflammatory colic can also result from the ingestion of toxic plants. The signs of inflammatory colic depend on its origins. They commonly include rolling, sweating, agitation and fever.
This type of colic occurs when ingesta cannot move through the horse’s digestive tract. This can be the result of a twist in or impingement of the intestines or a physical blockage, such as from dry, stemmy forage. Horses with impaction colic often try to roll, bite their flanks and display other signs of discomfort. They may or may not have a fever.
Examination of the contents of Cookie’s stomach revealed the problem: A sticky mass of persimmons, had settled into the pyloric sphincter like a plug in a bathtub, taking up about 80 percent of Cookie’s stomach.
The copious amount of reflux fluids told the veterinarian that something was preventing the pony’s stomach contents from passing through the digestive tract. As the stomach filled, the pressure within it increased, causing intense pain. A person in this situation would vomit, but horses don’t have that capacity. In fact, if the pressure had not been relieved via the nasogastric tube, Cookie’s stomach may have ruptured.
Although Cookie felt better after his stomach emptied, he wasn’t cured. Noting the color and sickening sweet odor of the reflux, the veterinarian asked Cookie’s owners if the pony had access to any kind of fruit. That’s when the mystery started to unravel—Yes, Cookie’s owner said, the pony had been in a field with a persimmon tree and had been eating the fruits.
The American persimmon tree (Diospyros virginiana) is native to the southern and eastern United States. When green, its fruits have a bitter taste but as they ripen they turn orange, soften slightly and become fairly sweet. Before it ripens, however, D. virginiana’s fruit contains tannins that, when bathed in stomach acids, form thick, sticky mass that adheres to other contents in the stomach. If several partially ripe persimmons are consumed at once, this mass—called a bezoar or a phytobezoar—can become so big it blocks the digestive tract. Such cases have been reported often in people, but very few had been documented in horses.
Suspecting Cookie’s blockage was caused by persimmons, and seeing his pain return as his stomach refilled with his own saliva and acid, the veterinarian recommended immediate referral to a university hospital. Once there, the clinicians used an endoscope to look directly into the stomach and confirmed that a sticky mass of persimmons was the source of Cookie’s problem. In fact, the mass was so large that it took up about 80 percent of the pony’s stomach.
In people, these types of blockages are resolved with surgery, but that option would be extremely risky for Cookie, not to mention expensive. Instead, the clinicians decided to try to break up the mass by infusing the pony’s stomach with mineral oil and other laxatives using a nasogastric tube. Meanwhile, they administered IV fluids and electrolytes to combat dehydration, and they treated Cookie for the gastric ulcers had begun to form on the irritated stomach lining. Cookie’s condition stabilized and he seemed slightly more comfortable but he wasn’t improving.
Then, one of the veterinarian’s recalled that Coca-Cola is sometimes used to clear clogged feeding tubes for both people and animals. Although it wasn’t clear whether the active agent in the soda was the carbonation, the acidity or something else, she thought it was worth a considering. Cookie’s veterinarians scoured the research journals for more information and eventually struck gold: They found a paper describing the use of Diet Coke to dissolve a bezoars in a woman. The researchers in that case hypothesized that the penetration of carbon dioxide bubbles into the surface of the bezoar worked to break up the fibers of the mass. They also suggested that the soda may also have had an acidifying effect on the gastric contents. Whatever the reason, the treatment had worked. A call was made and his owners agreed to giving the experimental Diet Coke treatment a try.
The clinician purchased two cans from the clinic vending machine and administered them to Cookie via his nasogastric tube. The next day he got two more, then another two the following day. All the while, the pony was monitored closely and kept hydrated. Then, on the third day of Diet Coke therapy, the clinicians once again used an endoscope to look into the pony’s stomach. To everyone’s delight, the bezoar was half its original size and very soft. Cookie was given another Diet Coke to celebrate.
By the next day, an endoscopic exam revealed no signs of the bezoar, at all. Cookie was incrementally returned to his normal diet and his blood work monitored. Ten days after he arrived at the clinic, he was discharged. Once home Cookie was sent to live in a new paddock, one that was far away from his favorite persimmon tree.
* This Case File is adapted from a Case Report originally published in EQUUS magazine.*
