Browsing tag: colic

Competition Vetting

Horse Jumping, photo by EDWARD McCABE

Horse Jumping, photo by EDWARD McCABE

Like everyone I know, I was glued to the Olympics – great job Team GB, especially our first Dressage and Show Jumping medals for a long time!
However, I wonder how many people think about the infrastructure and planning that go into keeping the horses fit, safe and healthy when they compete?
I’ve been a treating vet at a lot of competitions over the years, including Endurance events, local, regional and National Championship Pony Club events (where the standard is often as high as at many BE competitions!) and the International Show Jumping at Sheffield Hallam Arena. I was also on the vet team as a student at Badminton back when they still had roads and tracks before the cross country.

The vets that people most often seen are those on the Ground Jury at competitions – the notorious “Trot Up” before the competition starts, and again (in eventing) before the horses go forwards to the show jumping phase. At Badminton and most other big events, there are two vets – one on the Ground Jury, along with two or three other worthies – and one in the Hold Box. If there is a question over a horse’s fitness to compete, they get sent to the hold box, where the second vet examines them to see if there is a medical problem rendering the horse unfit. This is a very contentious area – I’ve never yet been at an event where the Ground Jury and the vets didn’t come in for a barrage of criticism over their decisions. However, it’s important to realise that they have to balance several factors:

Firstly, if a horse is unlevel on the trot up, it may be truly lame, or it may have a “mechanical lameness” – in other words, an abnormal gait that is non painful, and does not render it unfit (on welfare grounds) or unsafe to compete. To help them decide, they trot the horse up before the competition, and then note down any anomalies of gait or stride.
Secondly, there are some horses with minor injuries who can appear far more badly injured than they actually are. This is the reason for the Hold Box – a horse with a mild lameness due to a stone in it’s hoof (yes, it does happen, I’ve seen it!) will probably trot up sound once the offending pebble has been removed; likewise, I once saw a hopping lame (7/10 at trot, for anyone interested) horse go 100% sound after a misfitting stud was removed.
Thirdly, of course, the Ground Jury and the vets have to watch the riders or grooms who are trotting up the horse. It’s an old joke in the profession that the shorter the skirt and tighter the top of a woman competitor, the more carefully you have to check the horse, because she’s trying to distract your attention from something!

The role of the vet as a judge of fitness is of course expanded in Endurance competitions, where every horse has to be checked at various points along the track to ensure it is fit to continue, and that its heart rate drops enough to be permitted to go on. Different events have different requirements for judging, but as a general rule, the horse has to trot up sound and well hydrated, and have a heart rate below a certain value (e.g. 80 beats per minute). I was at one big competition once where there was a dispute over whether the (leading, international competitor’s) horse was sound or not. The decision was passed to a panel of 3 vets, none of us having seen the horse before that day, and its soundness or otherwise put to a secret ballot.

This used to be standard practice at two- and three day events, when there was a roads and tracks phase before the cross country. In these competitions (and there are still a few ongoing, regional Two Day Events in various corners of the country), the vet is present simply to determine whether the horse is fit and safe to continue. I once had to pull a horse because it was obviously “not right” – not an easy decision for a vet student at a CCI 3*! The rider appealed the decision – and while we were waiting, it tied up completely, and had to be recovered by the horse ambulance. I still shudder to think how badly it might have been injured if we had allowed it to run cross country.

At these events, riders, trainers etc can be very keen for the vet to pass a suspect horse as sound (although strangely, it doesn’t seem to be such a problem at Pony Club) – however, we’re really not trying to ruin your day (honest, and no, we don’t get paid to “fail” some competitors horses either), we’re just trying to make sure that an injury doesn’t ruin your horse’s week, month or season!

Of course, that brings me on to the treating vets at an event. Any equestrian competition will have a vet either on call or – especially at big events – on site. Some events (like the Pony Club Championships, Badminton or the International Show Jumping) will have the horses stabled on site. At these, there will usually be some vets assigned to the stables area, and others out on the course or at the arena.
Nowadays, we also have access to Equine Ambulances and their fantastic staff. They may look like normal horse trailers, but inside they have slings, winches, padded walls and often lowering floors – everything you need, in fact, to quickly and safely evacuate an injured horse.
The job of the course/arena vets is to be first on the scene and assess the state of the injured horse. They will give first aid, stabilise any strained tendons or suspicious fractures, and then decide where to send the horse. The big decision to make is whether it’s best to send the horse back to the stables (and if so, on foot or in the ambulance?), or refer them directly to a hospital facility. Fortunately, injuries that need immediate referral are rare; and most cases will be sent back to the stables. While assessing the horse, I like to have screens available – it doesn’t mean I’m preparing to put the horse down, but it does mean I can examine them in a calmer, more private environment. If we do need to put a horse down, we’ll usually try and move it off the track or away from the arena in the ambulance, to get some privacy.

While the course vets have to perform in the blaze of publicity, the stables vets are equally important. During the competition, the stables vets will keep in touch with their colleagues on the course, either by phone or (usually) radio. Quite often we’ll listen in on official channels as well so we can be leaning the right way if there is an incident! It’s the stables vets who will deal with most injuries and accidents during the competition, and it can get pretty hectic, stitching up rows of horses in succession…
At many competitions, there will only be a couple of us, looking after several hundred horses, 24 hours a day. I remember one memorable competition several years back where the night after the cross country phase, I got about an hour’s sleep – the rest of the night I was up treating the colicing, the sprained and strained, and the just “not quite right”. Most of my patients that week were mildly dehydrated – it’s amazing how much more horses need to drink after competing in hot weather! That’s the only time I can remember when I had to ring up a local practice to borrow more electrolyte salts, because I’d used up everything I took with me… (And the next year, when I took boxes and boxes of the stuff, they competed in gales and torrential rain, and I actually had cases of rain scald to treat… Well, that’s the English summer for you!).

If you are concerned about your horse, talk to your vet or try our Interactive Horse Symptom Guide to see how urgent it might be.

Part 3: Surgical Colic

As we saw in the previous part of this series, Medical colics are those which can be managed medically, usually on the yard. However, about 1 in 10 cases of colic require emergency referral to an equine hospital for surgery.

This is what most horse owners are terrified of. The general indicators that a horse has a surgical colic are:

1) Heart rate over 60 that isn’t relieved by injectable painkillers.
2) Dilated loops of small intestine on rectal exam.
3) Positive stomach reflux from the stomach tube.
4) A definite rectal diagnosis of a surgical problem.
5) “Toxic rings” – dark red or purple gums, that indicate that the horse is going into toxic shock.

Of course, it varies between horses, and the vet has to make a judgment call based on all the evidence available.

We also have to talk to the (by now usually frantic) owners about costs. Colic surgery usually costs between £4000 and £5000, but can easily be a lot more. Even if the horse is insured, it is important to check how much the insurance company will cover – there are a couple of companies out there who will only cover part of the costs of emergency surgery. If in doubt, always call your insurer’s helpline.

However, colic surgery is one of the most genuine emergency operations there is – and it can be truly life-saving.

So, what causes a surgical colic? Probably the most common are:

1) Twisted bowel. If a length of bowel twists around itself, it can cut off the circulation. At this point, the gut begins to die, and unless it can be removed by surgery, and quickly, the horse will go into toxic shock and die. This commonly happens in the small intestine or occasionally the colon, but there’s also a condition where the caecum gets turned partially inside out (an intussusception).

2) Small intestinal blockages. Horses rarely eat things that get stuck in the small intestine (although it can happen). More commonly, a really heavy worm burden can simply block up the bowel; with the bowel overfull, the blood supply starts to fail, and the gut, again, can die. I once had a patient who was a little foal with a severe colic; we removed two gallons of worms from her small intestine!

3) Strangulating Lipomas. These are really common in older horses and ponies. A small, benign, fatty tumour forms somewhere in the abdomen, causing no harm at all. However, it grows on a stalk, and eventually, the stalk gets wrapped around a length of gut, cutting off the blood supply… This results in the bowel dying, as if it had twisted. Fortunately, these are usually really simple surgical procedures; unfortunately, older horses and ponies are less likely to be insured for surgery.

There are also a number of medical conditions that can mimic those requiring surgery – particularly peritonitis and anterior (or proximal) enteritis. Horses with these conditions are often referred for possible surgery because it’s very hard for the vet in the field or on the yard to be 100% certain they’re not surgical. I think that most of us would say it makes a lot more sense to have the horse at the hospital, with a surgeon on call, to make the definitive diagnosis, rather than waste time in the stable, and risk having to then decide it needs surgery when it’s still an hour or more away in travelling time from the hospital!

So, what happens when the vet decides that a colic case isn’t suitable for medical management?

Firstly, they’ll talk to you about the options. If a horse isn’t insured, or there’s no money for treatment, it is a perfectly respectable and responsible decision to decide, sadly, to put the horse to sleep rather than prolong its suffering.

Hopefully, of course, that won’t be the case. Once you and the vet have decided that referral is the way forward, your vet will get in contact with a referral hospital. If you’re very lucky, it will be one run by your vet’s practice, but in most cases, it will be a specialist referral hospital. I must say here that not every centre with surgical facilities is able to cope with emergency colic surgery – they need not only to have the facilities (knock-down box, operating theatre, recovery box etc), but also the staff (not only a surgeon, but also enough vets and nurses to take care of your horse in the vital recovery period). Your vet will have a list of suitable referral hospitals – generally, its best to send the horse to the closest one with the shortest transport time, but your vet will be able to advise you.

Making an emergency referral is simple – but only your vet can do it. A referral hospital will not accept referrals from the horse’s owner! Once you’ve made the decision to refer, your vet will call them and speak to the veterinary team on call, who will be available 24/7/365 (when I was part of one such team, we ALWAYS seemed to get our referrals at about 10pm!). They’ll let him or her know what they want done during transport – generally, they’ll describe what painkillers they want given, and what samples they want taken (don’t be surprised if your vet gives you a couple of blood tubes to take up and give to the referral team). In addition, they’ll sometimes ask the vet to put in a stomach tube and tie it in for the journey – this is to prevent the stomach from getting over-full and bursting if there’s an obstruction in the small intestine. Don’t forget your horse’s passport – legally, they do need it even when being rushed to emergency surgery.

Your vet will generally give you directions and a contact number for the hospital, and send you on your way. Remember, they can’t normally go with you, because your horse’s colic, while devastating, is probably only one of several cases they’ll have to deal with.

If there’s a problem (e.g. your horse getting distressed) in transit, call your vet or the referral number you were given – but if at all possible don’t stop unless they tell you to! Remember, you’re on your way to the best equipped help available.

On arrival at the hospital, you can expect to be met by the veterinary and nursing team. Your horse will be rushed to an assessment area, and you’ll probably be given a lot of scary-looking paperwork to sign. Generally, this comes into 2 parts – firstly, you’re signing to give consent for whatever they need to do (and remember, a lot of drugs aren’t technically licensed for use in horses, because the manufacturers haven’t paid for an official license for that drug in horses. It doesn’t mean a drug is dangerous or experimental, it’s probably used on a daily basis by the hospital. You’ll have to sign consent to use unlicensed medication – it’s absolutely routine, and nothing to worry about). Most hospitals will also ask to see your passport – if you haven’t got it, or it isn’t signed to mark the horse as “not intended for human consumption”, legally the hospital can refuse treatment (although they rarely do).

The second set of paperwork you’ll sign is a bit more pedestrian – you’ll be signing to say that you will pay for any treatment!

While you’re contemplating the paperwork, your horse will be undergoing another examination by the veterinary team. This is to establish what’s going on, and what’s changed since your vet examined him back on the yard. They may well repeat some tests – most colic conditions are dynamic (i.e. constantly changing), and sometimes the change is more useful in working out what’s going on than a one-off test. Other tests they may wheel out include ultrasound – the powerful ultrasound systems available in a hospital environment can give the vets a lot more information about what’s going on. The vets will then make a decision about what to do – don’t be disappointed or worried if they don’t rush immediately to surgery! They may decide to try a course of medical treatment first (remember, they don’t have to rush as much as your vet does – if your horse’s situation deteriorates, they can operate at a moment’s notice).

In many cases, however, they will decide to take the horse straight to theatre. If so, you normally won’t be able to follow, so I’m going to describe what happens once you’ve been gently steered in the direction of a waiting room.

To begin with, the horse will have an intravenous catheter fitted, to allow easy access for fluids and drugs. A horse with colic is systemically weakened, so will almost invariably be given intravenous fluids during surgery. He’ll then be given a premed – this is a sedative, designed to make induction into anaesthesia gentler. It will usually contain the drug acepromazine, because the use of this before surgery has been demonstrated to reduce the risks of anaesthetics.

He’ll then be led into a knock-down box: this is a special padded room, designed to make induction of anaesthesia safer. Then he’ll be anaesthetised with an injection containing (usually) a mixture of 2 anaesthetic agents, ketamine (no, it’s not a tranquilizer, it’s an anaesthetic) and diazepam or a similar drug. Shortly after the injection, he’ll go wobbly, and then quickly lie down.

Once he’s asleep, the team will swing into action: a tube will be passed down his throat to help him breathe and he’ll be moved into the operating theatre. While this was going on, the surgeon(s) will have been scrubbing up, ready to start.

Once he’s in theatre and safely ensconced on a well cushioned table (to prevent pressure sores etc), he’ll be put onto anaesthetic gas to keep him asleep.

Colic3 - SurgeryThe surgery involves a long incision down the midline of the belly. The surgeons can then have a good look through all the intestines, to find the problem. This is the exciting, sexy bit, but it’s actually pretty simple in principle: “if in doubt, cut it out”. In other words, removing devitalized (dead) bowel, emptying out anything in the bowel that shouldn’t be there (e.g. a caecal impaction), replacing anything that’s got stuck in the wrong place (e.g. an entrapment) and untwisting anything that’s tied up. There are usually at least 2 surgeons, because one person is needed to hold loops of intestines (and they don’t stay still – sometimes they wriggle around in your arms)! Meanwhile, the anaesthetist will be carefully monitoring all sorts of parameters (heart rate, blood pressure, ECG, reflexes, breathing and blood gasses can all be monitored at many hospitals) and adjusting the anaesthetic and any other drugs to give the safest and most effective anaesthetic.

Once whatever the problem was has been found and (hopefully) sorted out, your horse will be returned to the recovery room. In many ways, this is the most dangerous part of the procedure. Horses are very prone to breaking things when they wake up, so everything is done to keep it as calm and quiet as possible. Sometimes, the veterinary team will help the horse to rise, using hoists and lifts; other times, it works out better to let him get up in his own time. In either case, he will be moved into a padded room, and left in dim light, as quietly as possible, so he wakes up slowly.

Once awake, and steady on his feet, he’ll be moved to an intensive care box; he’ll almost certainly be on a drip to keep him hydrated. At regular intervals through the next 24 hours (or longer) he’ll be checked by vets and nurses. In some cases, the guts don’t start working properly on their own, and medication may be needed to encourage motility (e.g. a lidocaine drip). Although everyone gets excited about the surgery, it is this recovery period that is in many ways the most important in getting a good long-term prognosis.

As time goes on, the vets and nurses will try and tempt the horse to eat – normally, we’ll try and get him eating fresh grass as soon as possible. As soon as he is stable enough and eating on his own, he’ll be sent home – most horses do better in their own home environment, so as soon as they no longer require advanced medical intervention, they can go home. Once home, it’s important that the discharge instructions from the hospital are followed – it can be tempting to try and speed things up, but don’t rush it! Major abdominal surgery takes time to recover from.

Colic is a worrying condition to have to deal with as an owner, especially as it often seems to come out of the blue. However, if you ever have to go through it, I hope that having read these blogs, you’ll have some idea of what’s being done, and why. Remember, our aim as vets is to help your horse and, if at all possible, send him home to you fit and well.

If you are worried your horse or pony may be suffering from colic, talk to your vet, or check the symptoms using our Interactive Equine Symptom Guide to help assess how urgent the problem may be.

Colic: Part 2: Medical Colics

In my last piece, I looked at how the vet will examine a horse with colic. Following this, and using all the information from the history and workup, he or she has to decide if the colic is Medical or Surgical. The terms are more or less self-explanatory: a medical colic can be managed with drugs, while a surgical colic needs emergency surgery.

As a rule of thumb, 9/10 colics are medical, and can almost always be managed on the yard.

So, here are the common causes of colic that we see in the UK1 :

1) Spasmodic Colic. This is probably the commonest, and perhaps the least understood; I estimate about 80% of Medical colics are Spasmodic. Spasmodic colic can be caused by a stressful event, mild dehydration, or be genuinely idiopathic (i.e. we don’t know what causes it!). It can also be caused by severe tapeworm burdens. In a Spasmodic Colic, a section of the gut goes into a spasm, preventing anything from moving past it. It can be acutely painful, but usually responds really well to management with drugs. For any horse that has two or more bouts of spasmodic colic, I’d always recommend a tapeworm blood test to make sure it isn’t part of the problem!

2) Impaction Colic. This is more common in some management systems – it is pretty rare, for example, in horses who live on grass. In these cases, the food in the large intestine dries out a bit too much, and turns into a putty-like material. It then gets stuck, typically at one of the 180- degree turns in the Large Colon. It’s also strongly associated with moderate dehydration – as a horse gets dehydrated, he will move water out of the gut in order to keep up his circulating blood volume. This is a clever trick, meaning a horse can survive levels of dehydration that would kill a human. However, if the water isn’t replaced, and he’s been eating dry hay, his gut contents can become so dry they cause an impaction. This is why, many years ago, bran mash and Epsom salts were fed after hard work – both are good ways of rehydrating the colon and Caecum contents.

3) Gut displacements and entraptions. These are a bit of a mixture – some are medical, some are surgical, some look surgical but aren’t, and some can be fixed medically but keep coming back so surgery is eventually needed. What many people don’t realise is that the guts are in constant motion. Occasionally, a loop of intestine goes “wandering around” inside the abdomen, and gets stuck behind something else (for example, into a little gap between the spleen and the kidney). These can often only be diagnosed by rectal exam, and can feel really confusing, where nothing seems to be exactly where it should be! Each case has to be treated on its merits, and many can be resolved by lunging – presumably because jiggling everything around helps the intestines to fall back into their proper places! Personally, however, my inclination is generally to refer the horse as a possible surgical case, because it’s amazing how often a trip in the box fixes a displacement or entraption. Of course, if they can’t be rapidly resolved, they need to have surgery to put everything back, before any permanent damage is done.

4) Sand colic – I’ve only rarely seen these; they’re normally caused by the horse drinking from sandy water. Over time, sand builds up in the intestines, causing irritation and sometimes an impaction. Management usually revolves around maintaining gut motion with laxatives and pain relief; however, surgery is sometimes needed to evacuate the sand and debris from the gut.

5) Inflammatory diseases, e.g. peritonitis or anterior enteritis. I’m including these here because they’re not strictly surgical. However, they can be really hard to differentiate from surgical cases, and they’re usually only diagnosed after referral, with the advanced techniques available at a referral hospital.

6) Other medical causes, e.g. diarrhoea, or stomach ulcers, can also cause a “Medical” colic; however, these cases require the underlying disease to be treated, at which point the colic symptoms will resolve themselves.

Treatment for medical colics is focused around pain relief and maintaining hydration. Spasmodic colics especially respond very well to a mixture of hyoscine and a pain-killer, which relaxes the spasming gut segment, allowing normal gut movement to be re-established.

Using a painkiller (e.g. injectable bute) can also be a really useful diagnostic test for whether a horse needs surgery – one of the standard guidelines is that a horse with a heart rate over 60 beats per minutes, 30 minutes after intravenous bute, is usually a surgical case. The other painkiller (flunixin meglumine) is almost never used, unless surgery is definitely not an option. This is because it is too powerful! Even horses with dead bowel can look bright, healthy and well, until the flunixin wears off. At that point, they crash, and are often too far gone to be saved.

Equipment for the medical treatment of colic

Equipment for the medical treatment of colic

For impactions, rehydrating the gut contents is vital, but pain relief is also really important. In these cases, Epsom salts and water by stomach tube are really useful. There is some controversy over the use of liquid paraffin in impaction colics. If the horse later has to go to surgery, the presence of liquid paraffin in the gut can cause major headaches for the surgeons; on the other hand, it can be a marvellous lubricant to help move things along. Personally, I tend to give any impaction colic a bucket by stomach tube containing a mixture of water, electrolytes and Epsom salts; and if I’m sure it’s not surgical, I’ll add in a litre or two of liquid paraffin as well. Liquid paraffin is horrible stuff to work with, and if all you’ve got to give it with is cold water, it’s not easy to mix in; I like to mix the water and electrolyte tablets or sachets together first in a bucket, then add the paraffin.

The tube is passed down the nose and (hopefully first time!) into the gullet (if it goes into the wind pipe, start again…), and down all the way into the stomach. To check it’s in the right place, I always feel for it passing down the throat, listen for air moving as the horse breathes, and then suck on it to see if I get lots of air back (means I’m in the airways) or nothing (means I’m in the gullet) or, worst of all, a mouthful of stomach contents. This means the tube is in the stomach, which is great, but it tastes truly vile! Once I’ve carried out all those tests, I’ll pour in a tiny amount of clean water, just to be sure – if the horse coughs, it means the tube is in the windpipe despite all my tests, but it’s not the disaster it would be if I’d poured in a couple of gallons of liquid…

To get this lot into a horse, some people use stirrup pumps – they’re a bit like bicycle pumps, and attach to the end of the stomach tube. This is used to pump fluid from the bucket down the tube – they’re great if you’ve got them, although you have to be careful not to overfill the stomach. However, most of us still use syphons and funnels. The tallest person present (usually me…) attaches a funnel to the top of the tube, then fills the funnel from the bucket. They then hold the funnel as high as they can, so the liquid runs down the tube into the horse’s stomach. You then repeat this until either the bucket is empty or the funnel stops running, which normally means the stomach is full. It’s messy, and can be physically pretty hard work, but it’s a vital part of treating an impaction colic. Personally, I quite often use it to rehydrate the gut of any severe medical colic, because anything that causes gut stasis can lead to a secondary impaction if you’re not careful.

I’d normally treat a definitely diagnosed impaction with injectable bute for pain relief. There is some evidence to suggest that the use of anti-spasm drugs like Buscopan can help to encourage normal gut action, even though they are designed to work as gut relaxants, but I think that particular debate is still open.

To maintain hydration, some vets also like to start a drip line for intravenous fluids. This won’t help the gut (any excess fluid will be excreted by the kidneys before it gets there), but it can help to support the circulation of the horse. Personally, my thinking is that most colics that are so severely dehydrated that they need a drip are either surgical or have another, underlying disease; however, there are always exceptions!

Chronic, ongoing colics can be a nightmare to manage – they’re typically low grade, spasmodic colics, or mild impactions. In these cases, a more thorough examination (including blood tests) is indicated, to try and rule out any underlying disease. Chronic impaction problems tend to be management related, and can usually be resolved with minor tweaks to management. However, your vet will often want to check your horse’s teeth – this is because dental problems can result in poorly chewed food, which can make impactions more likely.

My experience with the chronic spasmodic colics is that if there’s no other underlying cause found, they can occasionally respond nicely to a course of probiotics. I had an incredibly frustrating case once of a horse that had repeated bouts of colic, that we never got to the bottom of. I was being called out every few weeks (and the yard was nearly thirty miles from the practice, which made each visit something of a nightmare!). Eventually I suggested we try a month’s course of probiotics… and the next time I saw the horse was nine months later for annual vaccination. Any further colic episodes, I asked? No, they replied – nothing since we started the probiotics. Although it isn’t a cure-all, it can apparently help in some cases!

Of course, not all colics are medical – about 10% require surgical management. In the third and final piece of this series, I will look at the indications for surgery, the types of colic needing surgery, and then I’ll go through what happens when your horse is referred to an equine hospital for emergency surgery.

1 This is based on my clinical experience in the Midlands, Wales and the South West of England. In some parts of the country, other causes will be more common – for example, on the South Coast, Sand Colic is more common. However, it seems to be fairly rare in most areas, so I’m not going to cover it in great detail.

If you are worried your horse or pony may be suffering from colic, talk to your vet, or check the symptoms using our Interactive Equine Symptom Guide to help assess how urgent the problem may be.

Colic: Part 1: Diagnosis and Workup

Horse colic examination and anatomy
When talking about colic, it’s important to have some idea of what the various parts of the equine gut are… So, here we go:
Stomach – quite small, and hidden away deep up in the ribcage.
Small intestine - this is very long, but quite narrow (perhaps 1 or 2 inches across). It is all coiled up throughout the abdomen.
Large intestine – this is divided into three parts:
The Caecum is a large sac perhaps four or five feet long, pointing forward, and can be heard on the right flank. Generally, it makes a loud gurgling noise every 20 to 30 seconds in a normal, healthy horse.
The Large Colon makes up a double U shape, lying on the bottom of the abdomen. It can be up to a foot across, but at each end is a sharp 180-degree bend; the bend near the pelvis (the pelvic flexure) is especially narrow.
The Small Colon runs from the large colon down to the rectum, along the top of the abdominal space.

It’s something all horse owners dread – colic. However, colic is a symptom, not a disease in its own right, and has a wide range of different causes. This is the first in a three-part series where I’ll be looking at colic in horses – its diagnosis and treatment, and what happens if your horse has to be referred for surgery.

Put simply, all colic is, is abdominal pain. However, before you’re tempted to dismiss it as a stomach ache, it’s worth remembering that the horse’s intestines are as complicated as a major chemical factory! Anything that causes disruption to their function is potentially life-threatening.

Occasionally, colic pain comes from a non-intestinal source, e.g. Liver disease (think ragwort poisoning, or liver fluke), or a kidney issue. In mares, it can also be caused by certain disorders of the reproductive tract. However, the vast majority are due to disease, damage or malfunction of the intestines.

If you call your vet and tell them that your horse has colic, they’ll treat it as an emergency, because it can be. They’ll generally take a bit of history from you, a quick description of what the horse is doing at the moment, and then they’ll head out to examine the horse. Most vets will also give instructions for what to do while you’re waiting; it’s important to do what they say, not what someone else on the yard suggests. This is because they may have an idea what sort of colic your horse has, and will try to tailor their instructions to the specific case. For example, some forms of colic respond well to being trotted around on the lunge; however, that can worsen other types.

When they arrive, the vet will want to establish three things:
Firstly, does the horse actually have colic? I’ve been called out to “colic” cases that proved to be laminitis; to a mare foaling down; once even to a tired (but perfectly healthy) horse sleeping in his stable!
Secondly, assuming it is a colic, is it a Medical or a Surgical Colic? (I’ll talk more about this distinction in a minute).
Third and finally, can they make a specific diagnosis of what kind of colic it is?

Every vet will have their own routine, but my workup goes something like this:

What’s the horse’s behaviour like? Is he alert, or dull and unresponsive? Is he thrashing about, or just looking at his flanks occasionally? Generally, a quieter horse is likely to have a milder colic, unless he or she is so toxic that they are depressed or spaced out. One exception is that some spasmodic colics are incredibly painful – however, the pain usually comes in waves.

Are there any droppings in the stable? Hard, dry lumps of faeces is suggestive of an impaction, or blockage; while very runny faeces or diarrhoea may suggest colic secondary to an infection, e.g. Salmonella.

Then I’ll start my examination:

Mucous membranes (gums are usually most accessible and reliable) – what colour are they, what is the refill time, are they tacky?
The normal colour is described as being “salmon pink”, and if you press with a finger for a moment, the colour should fade to white, then return within 2 seconds. They should also be nice and moist to the touch. If they are red, or purple, or the colour doesn’t fade, it is highly suggestive of toxic shock (like septicaemia). This is a marker of a really, really severe injury to the gut wall, that’s allowing bacterial toxins to enter the circulation. If the refill time is greater than 2 seconds, or the membranes are tacky or dry, it suggests dehydration and/or shock.

Heart rate - how fast, is the rhythm good? As a (very rough and ready!) general rule, a heart rate under 60 beats per minute implies a Medical colic, while over 80 suggests a Surgical case. If there’s an abnormality in the rhythm, it can mean heart disease as well, or severe toxic shock.

Gut sounds - what do the guts sound like in all 4 quadrants?
This is where you’ll see your vet putting a stethoscope to the horse’s flanks, listening to the guts. The normal, healthy gut makes a wide range of bubbling, gurgling noises (the sort that anywhere else you would associate with really cheap plumbing!). The bottom left is the left Large Colon, bottom right is the right Large Colon and perhaps some Caecum, the top right is the base of the Caecum, and the top left is mainly small intestine. This is one of the most useful tests we can do – reduced sounds mean the guts are “slowing down” – this can mean an impaction or blockage, but it can also mean a serious disease e.g. a twisted gut. Increased sounds is generally a good sign, as it usually means a Spasmodic colic.

Finally, I’d want to take the temperature (a horse with a fever is likely to have another disease, e.g. Salmonella, that is the underlying cause of the colic), and then, if at all possible, do a rectal exam. People get very excited about this, and it’s one of the standard jokes about vets, but I’d like to go on record and say that I doubt anyone actually enjoys rectalling a horse! Apart from anything else, it’s dangerous to the vet, and uncomfortable to the horse… However, it can provide more information than almost any other test. What we’re feeling for is anything unusual: is the large colon a normal size and texture? How about the Caecum? Can you feel the small intestine? Usually, the small intestine is almost impossible to feel – it just slithers out of the way. If, however, you can feel thick, swollen loops of intestines (they feel a bit like black pudding, or really thick, soft sausages, if you’re interested!), it is an indication of a complete blockage in the small intestine, which needs emergency colic surgery. On the other hand, if you feel a doughy, squishy mass in the colon, that means the horse has an impaction.

Sometimes, if there is doubt about whether food is passing from the stomach or not, the vet will pass a stomach tube and see how full the stomach is. This looks really easy in theory – you pass a tube up the horse’s nose, he swallows it, and then you syphon out the stomach. If you get lots, it’s too full, if not, it’s fine. However, not all horses are quite so easy! Some horses are really difficult to get to swallow the tube, and it can take several attempts to make sure it’s not in the windpipe (which would be a disaster). Also, the equine stomach is, as one equine surgeon I know once put it, “a fantastic organ – it can be completely dilated (full), and you’ll get nothing out of it until you move the tube half an inch, then it all comes spurting out”. However, if there’s any doubt, it can be a great tool to ensure that there isn’t a rapidly life- threatening blockage; it can also be emergency first aid to prevent the horse’s stomach rupturing in a severe surgical colic.

The vet will also sometimes take blood samples – we tend to hold onto these in case they’re needed, but the main things we’re looking for are:
1) Evidence of dehydration – the blood tests will allow us to quantify the degree of dehydration, making it easier to plan a course of treatment.
2) Evidence of infection – if the white cell count is significantly abnormal, it suggests there may be something else causing the colic that we might need to look into.
3) Liver and kidney function – sometimes liver or kidney disease can present as colic
4) MOST IMPORTANTLY – Fibrinogen levels. Fibrinogen is a substance that can be used to assess inflammation and tissue damage – a high Fib level in a colic case is very suggestive that the gut integrity is damaged, and that surgical intervention may be needed.

There’s one other sample that can be very useful, especially as a “rule out” test if the clinical findings are contradictory or unclear. This is a peritoneal tap. This test carries some risk, but sometimes it’s the best way to find out what’s going on inside the abdomen. The belly of the horse is clipped, and prepared so make it as sterile as possible – we don’t want to risk introducing infection. The area is numbed with local anaesthetic, and then either a small incision is made with a scalpel and a blunt cannula inserted or (more usually) a small sterile needle is VERY CAREFULY inserted through the abdominal wall. The fluid that comes out is collected in a sterile sample pot for examination. The risk, of course, is that damage is done to the intestines; however, we’re very careful to avoid them as far as possible, and instead to collect the fluid that surrounds the intestines, the peritoneal fluid. In the lab, the numbers of cells can be counted to assess if there’s infection in the belly (peritonitis); however, in the field we can tell three things:
1) The tap fluid is clear (you can read text through it) yellowish – this suggests that the abdomen is basically OK, and means that in the absence of any other findings, the case can be managed medically.
2) The tap is cloudy, reddish or umber in colour - this means severe damage to the gut walls and/or peritonitis (infection in the abdominal cavity). This horse needs urgent referral for investigation at a hospital.
3) The tap contains gut contents (green or brown, lumpy) – sadly, this means that the intestines have ruptured; the horse is highly unlikely to survive. Alternatively, this may mean that the needle has gone into a part of the intestines, so if I get this, I’ll usually repeat the tap a few inches away, to make sure. If the needle has damaged the intestine, it’s not a disaster, but it is something to be avoided if possible.

So, using all the information from our history and workup, the vet has to decide if the colic is Medical or Surgical.

The terms are more or less self-explanatory: a medical colic can be managed with drugs, while a surgical colic needs emergency surgery.

As a rule of thumb, 9/10 colics are medical, and can almost always be managed on the yard. In my next blog, I’ll be looking at these Medical colics, their causes and treatment.

If you are worried your horse or pony may be suffering from colic, talk to your vet, or check the symptoms using our Interactive Equine Symptom Guide to help assess how urgent the problem may be.

Looking after the Older Horse

When I was training as a vet, a 20 year old horse was considered really quite old. Now, however, I regularly find myself working with healthy horses in their late twenties and thirties – even a few that go on into their forties!

That said, horses don’t age uniformly – one may be sprightly and fit at 30, while her paddock mate is really feeling his age at 20, so there’s a lot of variation. The challenge is maintaining them at the best quality of life for as long as possible.

To do so, we need to consider three things:

• Work and exercise
• Preventative health (worming, dental care etc)
• Disease management and medication

I’ll deal with these in sequence, although really they are of course all interconnected.

Work and Exercise

PerryI’d like to introduce Perry, a horse I’ve known for many, many years. Born in 1986, by 2002 Perry was a successful Eventer, competing on the Affiliated circuit, and usually well up in the places. However, by then he was starting to slow up a bit, and his then-owner decided it was time to reduce his workload. He was struggling in particular with the dressage and show jumping, so they sold him on to a friend of mine as a Pony Club horse for Tetrathlon. All he had to do was carry his (fairly novice) rider round a cross country course – the phase he enjoyed the most anyway. Relieved of the need to work in an outline, or in collection, he flourished at Tetrathlon, going on to compete at the National Championships.
Of course, in time, his low-grade arthritis (which I’ll talk about more later) meant that he was struggling with the cross country requirements, and he moved into a semi-retirement as a hack. He’d seen it all, done it all, and was as close to 100% in traffic, tractors and low flying aircraft as any horse could be.
For most horses, as long as they can work, they want to – generally (and there are always exceptions!), it isn’t in a horse’s best interests to take him out of work one day and retire him to a field. A gradual wind-down over several years is kinder, and helps to keep him interested and alert.
So, by changing career, Perry had an extra five years of competition, and then many more years of useful work – simply because his various owners were wise enough not to over face him, but to play to his strengths.

Preventative Health

I’ve talked before about the importance of regular dental work – in the older horse, it is doubly important. As the horse ages, his teeth undergo a number of changes. Although it appears that teeth grow constantly, that is in fact an illusion – the adult teeth are pretty much a fixed length, but most of the tooth is hidden away within the gums (the reserve crown). As the tooth is worn down by chewing, more of this reserve is extruded (which is, by the way, the basis of ageing horses by dentition). However, sooner or later, this reserve is expended, and the teeth “cup out”, becoming small, loosely held, concave structures, of limited use for chewing. Good, regular dental care can help delay the onset, and can help the horse to manage as the teeth cup out. Remember, as long as there are a few pairs of teeth in occlusion (i.e. Facing each other), the horse can still chew, he’ll just be very slow about it! In my experience, teeth generally start to cup out about 30-35 years of age, but it depends on their dental history – more use and wear and tear means the teeth are ground down faster.
Worming is also inceasingly important in the older horse, simply because although they may have higher immunity to worms (this is still debated, but does seem likely), they also have less reserves to cope if they have a heavy infestation. The spring is a particularly risky time, as sometimes large numbers of small redworms can emerge all at once, causing massive gut wall damage. It is important to make sure that at some point over the winter, you use a wormer that is active against hibernating (hypobiotic) worm larvae – currently, the only wormers on the market that have this activity are a full 5 day course of Panacur, and (reportedly) Equest.

Foot care is always important, as older horses can suffer some terrible hoof capsule problems if left untreated.

I always recommend that people keep up vaccinating their horses, even if they’re not competing or going out. Equine influenza probably isn’t essential in a stay-at-home horse or pony (although they can still contract it if they’re in contact with a younger friend who does go out and do), but Tetanus vaccination is essential. Just because a horse is old doesn’t mean you can stop vaccinating, because tetanus kills horses of any age just as easily. It’s also a really useful opportunity to have a general “MOT” and get your vet to check the horse over thoroughly, to detect and problems before they become too serious.

Disease Management

Although many horses lead a long and healthy life, the probability is that as they enter old age, they will suffer from one or more “chronic diseases”. These are generally low-level conditions, and in the older horse are usually manageable rather than curable. Probably the most common are arthritis and Cushing’s disease, but malabsorbtion diseases and some tumours aren’t that uncommon either.

The key factor is managing the disease in such a way that the horse doesn’t suffer from the symptoms, and is able to keep up as much work as possible, for as long as possible.

Arthritis is perhaps the commonest condition of older horses, and those that aren’t so old. In most cases, it is due to simple wear and tear on the joint surfaces. The harder a horse has worked, the more rapid the onset of arthritic changes. It’s often the case that, initially, a horse will have trouble working in an outline, and perhaps with show jumps, but hacking and cross country, with it’s more open jumping style, is less of a problem. This of course was exactly the case with Perry. Managing arthritis is a lot more than just monitoring exercise, however – nowadays, we no longer need to just accept “a bit of stiffness” in the older horse. It’s often best to use several different strategies. I generally recommend a combination of joint supplementation (feed supplements such as Cosequin and Newmarket Joint Supplement are the most popular, while injectables like Adequan are more expensive but possibly more effective) with analgesics (bute and/or Danilon, usually) as required. Although painkillers like bute don’t address the underlying disease, they reduce the inflammation and associated pain. Although there can be side effects, it really isn’t fair to put a horse through the pain and discomfort of arthritis without some pain relief; if side effects are a particular concern, Danilon has a much lower risk, although it seems to be a little less effective. Its usually best to start out using bute only as required, and then build up the dose as necessary. Perry, for example, started using bute about 10 years ago, but just a sachet or so immediately after a competition. As he’s got older, he uses more, and at the moment he’s on an average of 4-5 sachets a week – enough to keep him comfortable (and galloping round his paddock like a yearling!).

Cushing’s disease (hyperadrenocorticism) is most common in older horses, and is caused by a micro-tumour in the pituitary gland. This results in an excess of circulating cortisol (a stress hormone), that causes the characteristic symptoms of abnormal fat pads (typically over the eyes and as saddle-packs), excessive drinking and urination, and increasing susceptibility to minor infections and laminitis. Ironically, the “classic” shaggy coat of the Cushingoid horse isn’t entirely due to cortisol – the presence of a tumour in the pituitary causes a malfunction in the part of the brain that controls body temperature, causing retention of a winter coat for longer. Cushing’s isn’t curable in horses, but symptoms can be partially controlled by management (regular clipping, diet and exercise control and remedial shoeing), or largely eliminated with some medications – Cyproheptadine (Periactin) may be of some use; however, Pergolide (Prascend) is highly effective, and is licensed for the treatment of Cushing’s.

Gut problems of one sort or another are also more common in older horses – these may be malabsorbtion issues, caused by thickening of the gut wall, or an increased susceptibility to colic. This may be due to a diffuse Lymphoma (a cancer of the white blood cells) which is the commonest tumour of older horses. In these cases, the key is to feed a highly digestible, high feed value ration, possibly with a probiotic to enhance digestion.

Tooth loss is also a problem in the older horse – as I discussed earlier, eventually the teeth “cup out”, at which point there’s little more that can be done, dentally. The next phase is that the tooth falls out, leaving naked gums. I remember once doing a regular tooth rasping on a 38 year old mare – I put a hand in to have a feel around, and four teeth fell out in my palm… (she actually did better once the teeth were out than she had in months!). An edentulous (toothless) horse needs a soft, ultra-high fibre diet; typically a mash made from fibre pellets or pencils. Horses can live healthily for quite some time on such a diet – however, once your horse has reached this stage, it is probably time to consider how long you can fairly keep him going.

If you can stay on top of all these points, you have every chance of keeping your older horse going for a long, healthy life – as Perry has had, and indeed continues to have.

If you are worried about any symptoms your horse or pony is showing, please talk to your vet or check how urgent the problem may be by using our Interactive Equine Symptom Guide written by expert equine vets.

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