Dentistry & The Older Horse

This article is from the March 2020 Horse Deals magazine.

Article by Dr Shannon Lee BVSc MANZCVSc. D.ICEVO of Advanced Equine Dentistry

As horses age so do their teeth, and just like older people, especially those who may not have prioritised good dental care earlier in life, it’s common for them to develop dental issues that are both painful and debilitating.
Finding and addressing these issues is one way in which we can help these horses to have an improved quality of life.

There are a number of common dental issues affecting older horses, some of which include periodontal (gum) disease, Cushing’s disease, tooth fracture, tooth root infection, altered/accelerated tooth wear, soft tissue injury from sharp teeth or altered tooth wear. The teeth of horses differ greatly from those of humans and these conditions they develop are specific so it is important that you choose an experienced equine dental vet to examine and treat these horses.

To be effective the examination must be carried out with the horse sedated and with the use of both a very bright exam light and a good clean dental mirror, both of which are only effective if the mouth has first been thoroughly cleaned and rinsed with clean water. Even after this initial exam, further specific equipment may be required to examine the teeth in more detail, one of the more commonly used and important of these tools is a dental x-ray unit.

Even with this age group, much of the tooth’s structure is still below the gum within the bone of the skull and so can only be effectively examined with tools like an x-ray. Probably the two most common conditions affecting older horses which often go undetected prior to this type of examination are serious periodontal disease and tooth root infection. Both of these are painful and debilitating, so their detection and treatment are a very important part of helping the health and wellbeing of older horses.

Possibly partially because horses are so stoic when it comes to dental pain and will often appear normal to their owners, even when they are suffering from very painful conditions e.g. tooth root infection, advanced gum disease, jaw fracture or nerve exposure. There are some external signs of disease, and if you have a horse with these then you need to seek the advice of a qualified equine dental veterinarian. Signs that you might see include swelling on the face or cheek, swelling on regions of the face may indicate tooth root infection, whilst swelling in the cheek can be evidence of feed packing as a result of advanced gum disease. A nasal discharge containing pus or having an unpleasant odour may be due to a sinus infection. Some changes in behaviour that you might notice include finding feed in the horse’s water, noticing them chew, stretch their jaw or yawn whilst eating, opening their mouths wider when eating and placing their tongue between their teeth. A horses breath shouldn’t smell unpleasant, if you notice this then it’s another sign that you have an issue. Please remember, however, that whilst seeing these signs means you need to act, most serious cases will not show externally obvious signs like these.

If you have an older horse (any horse in their late teens and above) then it is important, for their comfort, to have their mouths examined regularly by a dental vet. For most horses, this will mean two visits a year (a dental checkup every 6 months), thanks to advances in detection of dental issues, even older horses that have not previously had this type of care can greatly benefit.

It is not unusual that owners worry that a visit from the dental vet will mean the possibility of teeth being removed, however, whilst there is a chance of this happening, it is important to understand that dental vets only remove these teeth because it is no longer possible to save them and because the presence of these teeth causes horses great pain. In other words, these teeth need to go as they do far more harm than good. If you are concerned about an older horse losing teeth, speak to your dental vet about it. In most cases horses do far better without the teeth, as whilst they have fewer teeth, they are also no longer in constant pain.

It is important to add that often people wait until they observe weight loss in older horses before speaking to a dental vet. Given that there are many causes of weight loss in horses, and if the horse hasn’t received regular care from a dental vet there’s a high chance of serious dental disease, it’s important not to automatically connect one with the other. Ideally, regular dental visits should begin within the horse’s first year of life and continue throughout life.

Weight loss in horses can be due to systemic disease (serious conditions affecting the entire body) and as such, any thorough investigation of weight loss needs to include a thorough dental exam, but shouldn’t be limited just to a dental exam.

An often overlooked and not well-understood cause of dental pain in older horses is the pain resulting from the exposure of nerves within teeth, and the subsequent infections that often result. Whilst being one of the most painful conditions, the signs are easily missed or confused as this photo should demonstrate.

Here you can see an exposed nerve canal full of grass, now remember that we are looking at a small dark area inside the mouth, and that when healthy, these areas are also dark. Couple this with the fact that there are other tissues which when healthy, look similar to this in the mouth and it is perhaps easy to see why these are frequently missed because of a poor exam or a lack of adequate equipment and training. In the image you can see two areas labelled one and two, can you tell the difference?

The dark circle with the feed inside labelled one is, in fact, a dead nerve ending and indicates x-rays are needed which will determine whether the tooth requires removal.

The dark circle with feed inside labelled two is a normal part of the anatomy of upper cheek teeth called an infundibulum.

Now remember when looking at these kinds of details, all of this takes place inside the mouth of a horse that can move, inside a dark space (hence the need for the bright light) looking at dark spots, looking for small dark holes.

When the nerve dies like this and the protective covering wears away, the canal that contained the nerve fills with feed. This feed becomes trapped and allows bacteria to live and grow there, eventually making their way to the tooth roots and causing a painful abscess.

Example

As mentioned earlier, often people are frightened that losing teeth will be somehow bad for their horse, so quickly let’s look at an example.

In this case, the horse was 24 years old when presented for a dental exam with a history of weight loss, a number of issues, including nerve exposure, tooth fracture and serious gum disease were identified.

After examination and x-rays, a total of eight cheek teeth were removed after nerve blocks were used to numb the area.

As you can see the removal of these painful teeth has not had a negative impact on the patient and in fact, they have gained a significant amount of weight.

Horses don’t verbalise their pain like us, they don’t stop eating when they have a dental problem, so pro-active dental care is the only way to protect our horses.

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