Browsing tag: horse dental problems

Sedatives and Sedation in Horses

We routinely sedate horses in practice – after vaccination, it’s probably the most common “routine” job that we do. So, what are we doing? How do the drugs work – and why doesn’t it always happen the same way?

“Sedation – a state of rest or sleep… produced by a sedative drug.”

That’s the dictionary definition, and it makes it sound lovely and simple – give a drug, and the patient goes to sleep. Of course, in reality (as usual with anything equine!) life isn’t that easy…

For those who haven’t seen it before, a sedated horse doesn’t lie down, but their head gets lower and lower, and they may require something to lean on to help them balance. It’s also important to remember that a sedated horse CAN still kick – they’re just much less likely to do so! It often seems that the horse is still more or less aware of what’s going on around them, but they’re too sleepy to care about it. As a result, we’d almost invariably use pain relief and local anaesthetic as well if we’re carrying out a surgical procedure.

There are a wide range of situations in which we like to use sedation. Generally, it’s to make the horse more amenable when something nasty or scary is being done to them. Of course, this varies from horse to horse. There are quite a lot of horses out there that need a sedative before the farrier can trim their feet; and there are others that will allow you to suture up a wound without sedation or even local anaesthetic (not recommended, but occasionally necessary).

Probably the most common reasons we sedate horses for are…

1) Stitching up wounds, to stop the horse wriggling!

2) Tooth rasping, especially when using power rasps and dremels

3) Some surgical operations – for example, many vets prefer to castrate colts under standing sedation, rather than a general anaesthetic. This is because sedation is much safer than a general anaesthetic… On the other hand, the surgery is easier and safer (for the vet, as well as the horse) if the patient is completely “out”, so it comes down to the type of horse and the preference of the vet doing the op.

It’s important to remember that all sedatives temporarily alter the way the horse’s brain and body works, and have a serious impact on the heart and circulatory system. As a result, they’re all prescription-only medicines, and your vet will want to satisfy themselves that the patient doesn’t have any underlying heart problems etc before using them. Overdose of a sedative is rarely fatal in a healthy horse, but it can still be dangerous, especially if there is any underlying illness that makes them less good at maintaining their blood pressure. Its also vitally important to tell your vet the horse’s whole medical history if you’re asking them to give a sedative – there have been cases of horses who were being treated with a (very safe) antibiotic (TMPS); the owner forgot to tell a vet this, and the combination of sedative and this antibiotic has resulted in a heart attack (technically, a fatal arrhythmia).

There are three routes by which we normally give sedation:

1) By syringe or in feed.
This is the slowest, least powerful and least reliable way to sedate a horse, but it has two advantages – you don’t need a vet to come and do it, and you don’t need to get so close to the horse to give it.
The drug most commonly used is ACP, sold as Sedalin or Relaquin paste. Occasionally ACP tablets are used, although there are strict restrictions on when a vet is allowed to prescribe tablets instead of paste. There is a newer drug now available as a syringe, detomidine (sold as Domosedan gel), which is absorbed across the membranes in the mouth so shouldn’t usually be given with food, but does work faster and give better sedation than ACP.

2) By injection into the muscle.
Many injectable sedatives can be given into the muscle – this injection is more reliable than by mouth, but requires much higher doses than if given into the vein (in my experience, you need 4-5 times as much, and it takes about twice as long to work). It’s only usually needed if the horse is too wild or dangerous to get a vein, but it’s quite useful to “take the edge off”, and then I can top up with intravenous sedatives if needed. The other situation where I’ve occasionally used it is when a severely colicing horse has to take a long ride in a box to get to a surgical centre. In these cases, I have sometimes given the driver a preloaded syringe so that if he horse freaks out or goes crazy in transit, they can give it something to calm it down and relieve the pain until they arrive.

3) By intravenous injection.
Intravenous sedation is by far the best option if possible – it works fast (usually 5-10 minutes), you need lower doses, and you get much better sedation than by any other route. This is what I’ll be concentrating on below.

There are three “families” of drugs used to sedate horses:

Acepromazine (ACP).
This is a very “dirty” drug, in that it affects a wide range of body systems. It can only produce mild to moderate sedation on its own, and the effects are very variable between horses. It’s important to remember that once sedation has been achieved; increasing the dose WON’T result in deeper sedation, just more side effects. It also has no painkilling properties.
There are two side effects in particular that we as vets watch out for with ACP. Firstly, it can lead to significant drop in blood pressure, because it makes peripheral blood vessels dilate (this is why it’s sometimes used in laminitis). The second effect is much more interesting – ACP is a mild muscle relacant of some muscle types, so it can be useful in azoturia and choke. There’s one exception though (male readers of a senstive disposition, look away now…): ACP is a very powerful relaxant for the retractor penis muscle. This is the muscle that holds the penis in the sheath, and even low doses of ACP usually lead to male horses “dropping” the penis. This can be useful, but unfortunately in some horses (especially stallions, with a larger and heavier penis than most geldings); the paralysis of the penis can be quite prolonged, which can result in penile trauma. In extreme cases, this can be permanent or lead to gangrene, requiring amputation. Bottom line – if at all possible, avoid using ACP in stallions and entire colts!
ACP does, however, have a place in sedation – when mixed with other drugs, it often prolongs sedation and means that the doses of each part of the combination can be dropped, reducing the risk of side effects.
A quick note on ACP tablets – under the current Veterinary Medicines Cascade laws, it is illegal to use ACP tablets instead of paste in horses unless the vet has a clinical reason (unfortunately, price isn’t considered good enough) to think that they are more appropriate. As a result, if your vet refuses to give you the tablets, they’re not trying to rip you off – they’re just obeying the law.

Opiates
Although opiates on their own are only very weak sedatives in horses, when combined with other drugs they lead to much deeper and smoother sedation than any other drug on its own. The drug usually used is butorphanol, which is a synthetic opiate (it’s a mu/kappa agonist/antagonist related to buprenorphine, for anyone interested) that has a fairly good painkilling effect as well as potentiating sedation from other drugs. Fortunately, it also has very few side effects, although its worth bearing in mind that any other opiates (e.g. Pethidine or Fentanyl) that the horse is given up to about 8 hours later won’t work quite like they’re supposed to, as the butorphanol will partially block their activity.

Alpha-2 Drugs
These really are the mainstay of sedation in horses (and in dogs and cats, for that matter). Alpha-2 drugs act by tricking the body into thinking it’s produced too much adrenaline, so it stops releasing it, resulting in reliable deep sedation. They’re also pretty powerful painkillers.
There are three drugs that are commonly used, with slightly different properties. Detomidine and Romifidine are both fairly long acting drugs (30-40 minutes after i/v use), and when mixed with butorphanol are the standard sedative preparation for intravenous use, or on their own into the muscle. Detomidine is also available in a syringe for oral use.
The third drug is xylaxine; this is a bit different in that it gives milder sedation, and only lasts 20 minutes or so. It’s particularly useful for sedating horses for nerve blocks etc, where in half an hour they need to be completely recovered and able to trot up.

Before I sedate a horse, I always have a good listen to the horse’s heart, and check its pulse and colour to make sure its cardiovasclar system is healthy. I’ll then double check it’s not on any medication, and then give i/v sedation.
I like to use either detomidine or romifidine mixed with butorphanol for routine sedation – I personally prefer detomidine, but that’s probably just because it’s what I “grew up” as a vet using! For longer lasting procedures, or if I want muscle relaxation (especially for dentals where I want the tongue nice and floppy!), I add ACP into the mix.
Dosage is incredibly variable between horses and experience and judgement is more important than all the book learning available. As a rule of thumb, the bigger the horse, the less sedative per kilo of body weight it needs (so Shetlands often need as much as a light hunter). In addition, it depends on temperament – the more highly strung or excited, the more sedatives are needed. The other thing to remember is that apparently identical horses, in the same circumstances, may react very differently – the dose that will have Alf so deep his head’s on the floor will have Brutus untouched, while Charlie is in the “Goldilocks” zone where he’s just right. Of course, it also depends how deep the sedation you want – although personally, I’ve found that if you aim for “light sedation” to start with, you usually end up having to top the horse up halfway through.
Once the injection’s been given, it is VITAL to give the horse time for it to work in a quiet, dim, calm place. If the horse gets excited while you’re waiting for the sedative to kick in, it won’t work well. This is doubly true for oral sedatives, but it applies to injections as well.
During the procedure, its sometimes necessary to top up, which is fine – the great thing about the drugs we use is that they work fast enough i/v that you can monitor their effects more or less in real time. Recovery is usually rapid and uncomplicated, although it’s important not to let the horse eat anything until it’s completely woken up, or it may choke.
Very occasionally, I’ve had a horse that refused to wake up, or went too deep. After my first one, I took to carrying the antidote (Atipamezole, aka Antisedan or Sedistop) with me when I sedated sick or old horses. It’s very expensive, but it works within a minute or two to reverse the effect of alpha-2 drugs – and once they’re reversed, the horse wakes up incredibly fast!

In practice, sedating horses is as much an art as a science, and there’s rarely one “right answer” – it depends on the horse, the circumstances, and what you’re trying to achieve. The main purpose is to allow us to treat your horse effectively and humanely.

If you are worried about any problems with your horse or pony, please talk to your vet or try our Interactive Equine Symptom Guide to help decide what to do next.

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.

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.

Tooth Care for Horses

Jack_in_StableI’ve been thinking about teeth this week – horses’ teeth in particular. That’s partly because my own horses are due for a dental check up, but also because there’s been a report in one of my journals that really made me think how much dental work has moved on in the last ten or fifteen years!

When I was training as a vet, an equine “tooth check” mainly involved grabbing the tongue, having a quick feel round, then rasping away at anything that felt sharp. If you were properly equipped, you’d use a gag (aka a dental speculum); if not, many vets were happy to work around the horse’s tongue and teeth.

Nowadays, that sort of cursory examination really isn’t good enough in many cases. There are a lot of very well trained and experienced vets, as well as good equine dental technicians (EDTs) who would probably need a sit down if they saw some of the things that were commonplace not that long ago!

We also have many more “paraprofessionals” now – EDTs who have a variety of qualifications, and there seem to be fewer quacks out there than there used to be. That said, if you’re asking an EDT to do your horse’s teeth, check out their qualification first: if something goes wrong, some insurance companies won’t pay out if the EDT isn’t registered with the BAEDT (British Association of Equine Dental Technicians).

For a start, a proper tooth check up needs to include a clinical examination of the horse – is he losing weight? Are there any lumps or bumps on her head that might indicate a tooth root problem? How well are his intestines working to digest his food? It’s also true that it is not possible to do a full mouth exam without a gag of some sort. If you’re brave enough, yes you can feel the outside edges of the teeth by running your hand up, but anyone who thinks that holding a horse’s tongue will stop them biting your fingers has either been very lucky, or hasn’t tried it! A gag really is essential so you can examine the inner surfaces of the teeth, and also so you can have a look at the mouth. Although you can learn a lot from feeling, there are some conditions that are easier to detect and evaluate by sight, using a head lamp or a pen torch to have a good look around the mouth.

Now, of course, we have to consider the horse himself. In my experience, about 1 in 3 horses aren’t safe even to examine without some degree of sedation. Yes, you can often get away with it – but once you’ve put a gag in, you’ve effectively given the horse a lethal weapon. He doesn’t have to turn his head that far or that fast to knock someone out, or worse. I’ve only had this happen once while I was working on a horse, but that’s enough for me to be very certain I don’t want anyone else to be injured.

Of course, only a vet can legally prescribe sedatives to a horse, so in many cases, this is where EDTs have to call in backup. And please note, I’ve found that ACP (e.g. sedalin) barely takes the edge off a nervous horse; for dental work, injectable sedatives are preferable.

Once the exam is complete, we need to decide what we’re going to do with whatever we’ve found. Most horses, especially those who are seen regularly, will have a few sharp edges where the tooth has grown into sharp points as part of its daily wear pattern – remember, horses’ teeth grow down from the roots constantly through life, and are worn away by the teeth opposite. If they don’t line up properly side to side, we get sharp edges and points (usually on the outside, by the cheeks, at the top and the inside, by the tongue, at the bottom); if the misalignment is front to back, we get hooks (at the front of the first cheek teeth, usually on the top) and ramps (at the back of the last cheek teeth, usually on the bottom). All of these changes can make it painful or difficult to chew if they are allowed to continue, and sharp edges can cause mouth ulcers. I’m sure everyone knows how painful those can be! It’s even worse if a tooth is missing – the opposite one will grow down into the gap. In severe cases, this can cause “tooth lock”, where the horse is unable to open its mouth because the overgrown tooth has locked into the gap left by the missing one.

If it’s just a matter of sharp edges, or small hooks, these can usually be fixed with a hand rasp; however, if they’re large a power tool may be required. Power tools come in two forms – either a reciprocating power-float, or a rotary dremel are usually used; personally, I prefer a dremel because the blade is guarded so is less likely to damage the soft tissues of the cheeks and tongue. One important thing to remember about power tools is that altough they make the work easier, they do impose some problems of their own. Firstly, it’s very easy to take too much off – I remember once seeing a horse whose owner was very worried because she’d had “the tooth man” (who wasn’t a vet or a qualified EDT) out and then the horse had been unable to eat afterwards. On closer examination, he had managed to power float the teeth as smooth as billiard balls so the mare was no longer able to grind any food. She had to live on porridge and mashes for several months, until the teeth wore in and the grinding ridges reappeared. The second issue is that power tools often generate a lot of heat, and if left applied to the tooth for too long can actually kill the tooth so that it rots and needs to be removed. Some tools have a built in water spray for cooling; otherwise, I only leave the cutting surface on the tooth for a matter of seconds, remove it, apply water if needed, then do a bit more.

Now, once again we need to consider sedation; the more you need to do, the more likely it is that you will need sedation, and personally, I almost always sedate horses if I’m going to use power tools like a dremel. I didn’t always follow this rule, until one day a very calm pony I was working on jumped forward and swallowed the running dremel. Fortunately, all was well in this case, because as I felt the dremel vanish down the pony’s gullet I managed to cut the power, and then retrieve it before it was all gone, but it certainly made me think twice before working on unsedated patients!
In addition, even a quiet power tool makes vibrations that the horse will feel through the bone of his skull. My experience is that it’s a very rare horse that will stand perfectly still and allow you to do a proper job, rather than rush through and say “that’s fine” just before you think the horse is going to start throwing himself around the stable!

There are a number of other problems we come across on regular check ups as well. One of the commonest is misaligned arcades, where one tooth grows out at an odd angle – often straight sideways into the cheek. These require very careful treatment, and often need seeing on a very reglar basis (I had one which needed seeing every 6 weeks a one point).

Another major problem I’ve seen is where there’s a really painful tooth, but nothing obvious on examination. These are often due to tooth root abscesses. Unfortunately, a horse with an abscess like this can’t usually be fixed with a simple course of antibiotics; we need X-rays to see exactly which tooth is involved and how badly, and often we need to remove the tooth. If it’s already pretty wobbly, this can sometimes be done in the field under deep sedation, although it tends to be a lot of physical work to rock it and work it out of its socket. If it isn’t wobbly yet, it usually means the horse needs to come into a hospital facility and have the tooth removed surgically. This can frequently be done under sedation, but occasionally a general anaesthetic is required.

You can find information about other tooth problems that horses can suffer from here: http://www.baedt.com/?c=5386

That said, the vast majority of dental problems I’ve seen can be managed at home, with a good examination, sedation if needed, and then appropriate treatment with either hand or, occasionally, powered tools.

Will I be sedating my horses? One, definitely yes – I have no wish to fight with a 17hh stroppy eventer! The little pony, on the other hand, I’ll see how she feels about it; if I can get away without, I certainly will, but with her there are no guarantees…

If you are worried about your horse’s teeth, talk to your vet or check out any symptoms with our Interactive Horse Symptom Guide to see what to do next.

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