Last week, we were pleased to be able to discharge two colic cases, one surgical and one medical, that both required intensive care and a great team performance. Successfully treating cases like these gives us the biggest buzz, as they really do demand an enormous effort.
The medically managed patient was Veg, a 22 year old thoroughbred gelding who presented with moderately painful colic and rectal examination diagnosed a severely impacted caecum. The caecum is a large structure in the horse that forms the junction between the small intestine and the colon or large bowel.
The small intestine feeds into the caecum and the large intestine is the exit, but as you can see from this image, there is a large blind ending sack where an impaction can form.
The image above shows the normal position of the caecum in the abdomen being on the right hand side and towards the rear.
So Veg’s caecum was packed solid with hard faecal material which must have built up over a number of days. This is an unusual type of colic and is most commonly seen when horses have undergone general anaesthesia for some other reason and is thought to be due to an upset in gut motility and possibly some drug interactions. When, as in this case, it is the primary condition, we must try and establish if there are any underlying causes. In older horses, dental disease can be a factor as the horse may struggle to adequately chew up his forage leading to longer lengths of fibre entering the caecum. Tapeworms are also linked with caecal dysfunction and so both these problems were considered. Veg was treated for tapeworms and his teeth were rasped. In order to soften up an impaction, it is necessary to give fluids both orally and intravenously. A venous catheter was placed and Veg was connected to overhead fluid bags so that large quantities of fluids could be administered. Oral fluids are given via a stomach tube which is placed up the horse’s nose. When passing a tube down Veg’s oesophagus we encountered an obstruction long before we reached the stomach. This is very unusual so we had a look down his oesophagus with our videoendoscope and discovered that the horse had a pronounced kink which was stopping the stomach tube. Under sedation and muscle relaxants, we were able to pass a much smaller diameter tube than normal, so that we could administer oral fluids, vegetable oil and epsom salts. The salts draw fluid into the intestines from the surrounding blood supply via osmosis and the vegetable oil lubricates the impacted faecal material as well as providing nutrition. Veg’s bloods were monitored for signs of infection or other systemic disease; one of the concerns with caecal impaction is that the bowel wall can become inflamed and damaged ultimately causing it to leak resulting in fatal peritonitis. In studies of large numbers of cases of caecal impaction, only 61% have been resolved successfully by medical management. Surgery was not considered as a sensible option in a 22 year old horse but thankfully after 7 days of intensive treatment the impaction softened up and eventually passed on into the large bowel and out!
Having passed the impaction, we were not out of the woods, as Veg then developed diarrhoea due to an upset in his intestinal bacteria. He was put back on intravenous fluids and various intestinal protectants and he duly returned to normal. Veg was a super tough patient and we were all delighted to see him recover.
Our Head Nurse Amy with Veg, his abdominal problems now resolved!
The second of the colic cases was Dutch, a 15 year old warmblood, no prizes for guessing where he was born! Dutch had previously had colic surgery, three years ago with a previous owner, when he had 12 feet of small intestine removed due to an epiploic foramen entrapment. The epiploic foramen is a natural opening bounded by the caudate lobe of the liver, the portal vein, and the caudal vena cava. The distal jejunum and ileum are the most common portions of the intestine that become incarcerated through the epiploic foramen. Although generally the intestine passes through the epiploic foramen from left to right, tearing the omentum in the process, it also may pass in the opposite direction to enter the omental bursa. So essentially a section of small intestine becomes trapped and the blood supply becomes obstructed causing the bowel to become devitalised. If this is not dealt with quickly by a surgical intervention the horse will die.
Dutch presented again with exactly the same condition. Luckily his owners acted quickly and brought him into the Clinic. He was very painful and an abdominal ultrasound together with a rectal examination allowed us to make the diagnosis of a second epiploic foramen entrapment. We took Dutch straight to surgery and manged to exteriorize the devitalised bowel. It is important to remove a short section of normal bowel either side of the damaged area so that the subsequent join only involves healthy, functional intestine. When suturing the two healthy ends of the bowel together it is vital to maintain as large a diameter as possible otherwise the intestine could become obstructed if a narrowing was to occur.
The dark red intestine towards the right of the image is the devitalised tissue which had to be removed.
Thankfully as a speedy admission and diagnosis occurred in this case, only three feet of intestine had to be removed. The post-operative care of this type of patient is critical to the outcome. Dutch was maintained on a cocktail of fluids designed to enhance his intestinal motility. There is a danger when having to resect small intestine, that the peristaltic movement of the bowel is slow to return or even absent resulting in flaccid, dilated gut, a condition known as ileus. This can prove fatal and so Dutch was carefully monitored using ultrasound to image his small intestinal function. All went well and he coped with re-feeding without any set backs so Dutch was allowed to return home after 7 days.