Colic (pain coming from the abdomen) is the number one medical problem of the horse, and, in my opinion, it’s the number one medical concern of horse owners. While the vast majority of horses that experience an episode of colic will not need surgery, if your horse has colic, you’re going to be worried sick, regardless. So, the most important thing for you (and your veterinarian) to do is to quickly determine is if the problem is so serious that it requires surgery, and to make that determination as quickly as possible.
Like I said, most horses that colic don’t need surgery. However, it has been shown that the survival rate for horses getting colic surgery goes down the longer the horse has clinical signs of colic. Otherwise stated, if you horse has a colic, you need to find out if the problem requires surgery as quickly as possible, and you need to get him to the hospital as quickly as possible. The percentage of horses that get colic surgery that are put to sleep on the surgery table because of the advanced nature of their disease is estimated to range from 8% to 24%, so to avoid a sick horse being one of those awful statistics, getting him to the hospital quickly is really important.
When I look at a horse with colic, I’m first trying to gather a bunch of data to tell me the likelihood that a horse is going to need to get to the hospital. If the horse needs to go for surgery, there’s no reason for me to keep him on the farm any longer than absolutely necessary. Of course, I don’t want to ship every horse to the clinic – that would just be a needless waste of time and money. So, I’m looking at a whole bunch of factors to help me make my decision as to whether you can stay home, or if you have to hitch up the trailer (or start calling for one).
There’s no single diagnostic test that is 100% accurate at telling you if your colicking horse needs surgery, and there are a lot of things that we look at. However, certain tests appear to strongly predictive of the need for surgery.
STRONGLY POSITIVE PREDICTORS (needs colic surgery)
- If your horse has colic, and a potent pain-relieving drug, such as xylazine or detomodine doesn’t stop the colic pain, or if the pain starts back within a few minutes of receiving such drugs, it’s a sign that the colic is serious. On the other hand, if your horse responds to those drugs, and the pain does not return, that’s usually a wonderful sign that surgery isn’t needed. NOTE: This rule does not apply to flunixin (Banamine®), which is not a potent pain-relieving drug. What I mean by that is that if your horse’s colic isn’t relieved by flunixin, it’s probably doesn’t mean very much. You shouldn’t just dump pain relieving drugs into a colicking horse anyway.
- Degree of pain – This one’s pretty simple. The more painful the horse, the more likely he has a problem that needs surgery. The horse that can’t be kept up on his feet is more likely to have a serious problem than the one that occasionally looks back at his side, or one that is lying down relatively comfortably.
- Abdominal fluid color and protein – This is a job for your veterinarian. There is fluid inside your horse’s abdomen that surrounds the guts. In a horse with a colic that require surgery, that fluid typically changes color, and the amount of protein in the fluid typically increases. However, it is more likely that a horse with normal abdominal fluid does not need surgery than it is that a horse with abnormal fluid does need surgery. The procedure to collect abdominal fluid is called an abdominocentesis.
- Abdominal distension – If your horse’s abdomen is blown up like a balloon, it may indicate that he has a problem that needs surgery. Of course, the call is somewhat subjective, but the association has been made: twice. Abdominal ultrasonography – This test is going to be most likely done at the hospital, but ultrasound of the abdomen, where the inside of the abdomen can actually be visualized, is a very good predictor of the need for surgery.
STRONGLY NEGATIVE PREDICTORS (probably doesn’t need colic surgery)
- Elevated body temperature – Colic typically does not cause horses to develop a fever. Fever is more consistent with things like infections or intestinal inflammation than it is with problems that need surgery. I’m not saying you should be happy if your colicking horse has a fever, just that he probably doesn’t need surgery, so at least there’s something to be hopeful about. Oh, and a horse’s normal body temperature is between 99.5 and 101 degrees Fahrenheit (37.5 – 38.3 Celsius).
PREDICTORS OF MORE LIMITED VALUE (although commonly done, and sometimes still useful)
- Rectal examination – A rectal exam – one of the more eye-opening parts of being a veterinarian, where he or she places an arm in the horse’s rectum, and feels around inside the abdomen – is certainly important, but it’s not always a great predictor of the need for colic surgery. Occasionally, a specific diagnosis can be made (say, if your veterinarian feels a “stone,” gas, or a gut full of hard manure); however, since about 60% of the abdominal cavity cannot be reached by a normal human arm, rectal examination may be of limited value in some cases that need surgery.
- Gut sounds – Roughly half of the horses that need colic surgery don’t have normal intestinal sounds (that’s something that your veterinarian can check with a stethoscope). Of course, that many that half of the horses that ultimately need surgery have good gut sounds, as well as many of the horses that don’t need surgery. You’ll need to listen to your horse’s abdomen, but you also have to evaluate several other factors.
- Mucous membrane refill time – Checking the time it takes for the blood to come back when light finger or thumb pressure is put on the gums (it should normally take no longer than two seconds), has limited value, unless the horse is very sick. If the colic goes on, and the horse starts to go into shock, changes in the capillary refill time and the character of the mucous membranes (from wet to dry) are significant, but it may be too late to do anything about it.
- Mucous membrane color - Color and refill time sort of go hand in hand. A normal horse’s gums are a nice salmon pink – if they’re purple, it’s a sign that the horse probably needs surgery, but it’s also a sign that a lot of bad things have happened, and that the prognosis probably isn’t very good.
If your horse starts to colic, you might think about making a check list of the variables above and make a scorecard of sorts for your horse. Follow the signs, and if you’d consider referring him for colic surgery, try to do it as soon as possible. It’s always better to send a horse that doesn’t ultimately need surgery to the hospital and have him come back, than it is to wait too long to send him and not be able to do anything about it.