Equine dentistry – is there a link to performance?

By Chris Pearce on 01 May 2018

Our guest blogger Chris Pearce, who is a Recognised Veterinary Specialist in Equine Dentistry explains……

 

Do you know the Five Freedoms?

All animals in the UK are entitled to the five freedoms – freedom from hunger and thirst, discomfort, fear and distress and from pain, injury and disease. Recognition of these individual factors in horses can be challenging though, as 500 million years of horse evolution as a prey animal has resulted in an innate drive for them to conceal pain and discomfort.

 

How many horses suffer in silence?

Horses are unable to communicate pain in an obvious way. Dental disease can cause marked suffering through debilitating and painful conditions such as severe overgrowths, fractures, root abscesses and periodontal disease, yet horses will often show no signs. Recognition, treatment and prevention of dental disease are fundamental aspects of responsible equine welfare.

Studies have shown that up to 70% of horses, and up to 100% of donkeys and geriatric horses have dental disease that would benefit from treatment if identified.1,2,3 Classic descriptions of signs of dental disease such as quidding (dropping food), halitosis (bad breath) and facial swellings, are comparatively rare, either being a sudden severe problem (like a fracture), or most commonly end stage dental disease following many years of deterioration.

 

Evidence now shows that horses alter their mastication patterns to cope with pain, but do not overtly demonstrate this. One study by oral endoscope examination of horses showing no outward signs of dental disease showed that 12% had dental fractures, 45% had periodontal disease and 65% had sharp enamel points with cheek lacerations.4 When multiple teeth are affected, or swellings appear on the head, or a smelly nasal discharge appears, then we are alerted to a problem that may have been developing for years.

Image: www.equinedentalclinic.co.uk

So does pain causepoor  performance?

Yes – pain caused by dental disorders is a significant cause of poor performance in horses but it can be easily overlooked; it will not necessarily be associated with an obvious outwardly apparent problem, or even one easily viewed by diagnostic imaging techniques, at least in the early stages. Research has shown that horses respond to pain in the following ways:

  • Head shaking
  • Quiet behaviour
  • Aggressive behaviour
  • Abnormal gait, posture, balance
  • Poor performance

 

Pain may persist long after the pain-producing stimulus has been removed. It can result in a prolonged pain that may even be considered a disease in itself, often termed ‘neuropathic pain’.

 

Which dental disorders do we need to look out for?

The main disorders likely to result in pain and therefore potential performance, gait and balance disorders are:

  • Soft tissue injuries – from sharp enamel points of cheek teeth, injuries to the ‘bars’ of the lower jaw from the bit
  • Dental pulpitis (inflammation inside the tooth)
  • Cheek tooth non-septic pulpitis (pulp inflammation)
  • Cheek tooth septic pulpitis (infection, often leading to a tooth root abscess)
  • Dental trauma e.g. fractured incisors
  • Deep infundibular caries (central decay) leading to dentine and/or pulp inflammation
  • Diastema and periodontal disease (food impacted between the teeth)
  • Dentine sensitivity from cracks, fissures, partial fractures
  • Dentine and possibly pulp exposure and bit contact (e.g. from ‘bit-seats’)

 

What are the symptoms of dental disease?

The commonly described symptoms of dental disease include:

  • Quidding (dropping food, difficulty eating)
  • Nasal discharges
  • Halitosis
  • Facial swellings

 

These are signs of certain advanced types of dental disease but evidence shows it’s a lot more complex than we may think. Dental pain, or ‘toothache’, or pain from a single painful gap (diastema) is rarely diagnosed, especially during the developmental phase of disease, when the pain could actually be at its most severe.

 

If a horse has dental pain on one side of the mouth, for example from a single or perhaps a few bad teeth, the unique arrangement of the teeth means eating on the other side of the mouth is a simple solution to avoid it.

 

Abscesses, or root disease of the cheek teeth furthest forwards may cause externally visible facial swellings. For the teeth further back, the swelling may develop internally within the sinus, or nasal passages, restricting airflow. Cold air passing over such a swelling at exercise could easily cause marked discomfort. The dental pulp has a high capacity for repair and the body’s own defence mechanisms can often resolve early problems without any external signs. If the disease overwhelms the local defences, it may not be obvious that a problem exists until days, weeks or even years later.

 

Can ‘correcting the bite’ improve performance?

Some dental technicians advocate that various types of ‘correction’ of the bite can improve performance yet none of these theories has ever been proven scientifically. A recent study on incisor bite angles has shown that horses naturally have a wide variation, reflecting the individual variations of anatomy, and that there is no ‘one for all’ formula.

 

Routine maintenance ‘rasping’ is important to prevent the development of focal overgrowths of individual teeth and remove sharp edges that could cause cheek bruising or ulceration, especially where tack is involved, but we should not fall into the trap that all horse performance issues can be corrected by rasping or ‘realigning’ the teeth. In some cases it can be dangerous, risking exposure of vital tooth structures if too much tooth is removed, or placing immediate uneven pressures across the temporomandibular joint (TMJ). These can create performance problems rather than cure them.

 

So how do I ensure my horse doesn’t have these problems?

For routine dental visits, rasping with proper balancing of the teeth to normalise the pressures across the arcades is recommended. In addition, the importance of a really thorough oral and dental examination, with a little sedation at every appointment cannot be over-emphasised. This will allow identification of developing problems, give options for early intervention and keep horses performing to the maximum of their ability. This thorough examination is key to healthy teeth. It may well involve a little sedation as well – do not be put off by this, as a proper examination with picks, probes and a mirror are not easy to perform without, and problems may be missed.

Image: www.equinedentalclinic.co.uk

 

What if I think my horse has a teeth-related performance problem?

A thorough head, oral and dental examination is especially advisable if there are any ‘head’ related issues such as head-shaking, head aversion, tossing or difficulties bitting. This should include:

  • Full external head examination
  • Thorough oral examination under sedation
  • Close-up oroscope camera imaging of the teeth to help to diagnose problems
  • Radiography (x-rays) of the head from a variety of angles to view all the tooth roots
  • Computed tomography (CT) can greatly help by allowing assessment of the insides of the nasal passages, sinuses, bone and even the teeth

 

Find out more about caring for your horse’s teeth here

https://www.horsedialog.co.uk/?p=1458&preview=true

 

References

[1]           Brigham E.j., D.G.R. (2000) An equine postmortem dental study: 50 cases. Equine Veterinary Education 12, 59-62.

[2]           Taylor, L. and Dixon, P.M. (2007) Equine idiopathic cheek teeth fractures: part 2: a practice-based survey of 147 affected horses in Britain and Ireland. Equine Vet J 39, 322-326.

[3]           Anthony, J., Waldner, C., Grier, C. and Laycock, A.R. (2010) A survey of equine oral pathology. J Vet Dent 27, 12-15.

[4]           Simhofer, H., Griss, R. and Zetner, K. (2008) The use of oral endoscopy for detection of cheek teeth abnormalities in 300 horses. Vet J 178, 396-404.

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European and RCVS Recognised Veterinary Specialist in Equine Dentistr


European and RCVS Recognised Veterinary Specialist in Equine Dentistry is one of the country’s leading equine veterinary dental Specialists. He runs the Equine Dental Clinic Ltd in Wimborne, Dorset, UK, a centre of excellence for equine dentistry offering routine, advanced and specialist referral services.

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