Evaluation and Treatment of Gastrointestinal Intussusception

Roman Lamberski, DVM

Daniel J. Burba, DVM, DACVS

Introduction:

There are many different intestinal diseases that can present to the veterinarian as a colic of unknown origin, one of which can be an intussusception. An intussusception is defined by a section of bowel telescoping into another section of bowel. The main areas where an intussusception can happen within the equine intestinal tract is in the small intestines (figure 1), between the cecum and the large colon, and the portion of small intestines connecting to the cecum. There is no predisposed age although it is most commonly seen in horses from 6 months to 2 years. The most common association of horses that develop an intussusception of the small intestines into the cecum is an infestation of tapeworms.

Clinical Signs:

Intussusception

Horses that develop an intussusception can become acutely painful. This can be seen by the animal pawing at the ground, rolling, kicking or looking back at their abdomen. When the horse is initially evaluated it can have a wide range of colic signs. There heart rate may be elevated depending on the amount of pain the animal is in or their level of dehydration. Gastrointestinal motility can be normal to decreased on the side of the lesion. Normally the horse will respond well to pain medication, but will become painful again when the medication wears off.

Diagnosing An Intussusception:

When the veterinarian rectally palpates a horse with a cecal-colic intussusception he may not be able to palpate the cecum on the right side of the abdomen, although he will be able to palpate a firm mass in the area where the cecum should be. When a horse with a ileal-cecal intussusception is palpated, the veterinarian may feel a cecum that has a very firm mass inside it. When the abdominal fluid is evaluated it is usually normal because all of the inflammatory cells are maintained within the intestines and do not enter the abdominal cavity. Ultrasound is a very good means to diagnose an intussusception. The veterinarian will notice a “target” lesion on the screen. That means that there is a loop of bowel within another loop and it looks like a target on the ultrasound.

Treatment:

Currently the only means to alleviate an intussusception is by surgery. There are two ways to fix the lesion, and it is dependent on how long the bowel has been compromised. If the lesion is caught early enough it may be possible to manually reduce the lesion without removing any of the bowel. This is not usually the case though, most of the lesions have been compromised and part of the bowel will be damaged to the point that it needs to be removed (Figure 2). The reason for this damage to the bowel is because the part that telescopes inside another piece of bowel begins to swell. The more it swells the less blood is able to get to that piece of bowel, this causes tissue damage due to lack of oxygen.

Prognosis:

It is very difficult to determine the outcome of this disease with surgery because there are many factors that determine the outcome. The main three however are, how long the horse has had the intussusception, how much of the bowel has been damaged, and where the lesion is located. The longer the lesion remains in the bowel the poorer the prognosis. This will only become evident to the surgeon when he is physically able to evaluate the lesion and the rest of the bowel. Also if the lesion is too large the surgeon may not be able to repair the bowel and have it function in a normal capacity for the horse. This is most commonly seen with a cecal-colic intussusception. When the cecum telescopes into the large colon it is possible for a large majority of it to become trapped. If this is the case the surgeon will have to amputate a great majority of the cecum, or altogether bypass the cecum by connecting the small intestines to the large colon. In this case the prognosis can be guarded, but with the proper surgery these horses can survive.

So as an owner what can be done to prevent this from happening to you? Regularly worming your horse using a dewormer that treats tapeworms is a good start. Should you have a horse that is diagnosed with an intussusception you should deworm the rest of your horses on your property with a double dose of dewormer. Also if your horse begins to look painful and he isn’t eating or drinking normally, don’t hesitate to call your veterinarian. Iit can make a big difference in the prognosis of the disease.