Finding the source of pain *H&H VIP*

Quite commonly vets are presented with the somewhat vague complaint of a horse “not being right”.

This may be accompanied with a drop-off in performance, which is often associated with grumpiness when the horse is being groomed or rugged up or when his girth is tightened.

The two main diagnoses being considered by the vet when listening to these presenting complaints are back pain or gastric ulceration. While these two conditions would not appear to be particularly similar at first glance, they do seem to mimic each other in a number of ways.

Horses with gastric ulcers often have vague clinical signs such as loss of performance or condition, pickiness with feed (especially hard feed) and resentment of girthing, saddling, rugging up and mounting.

Some, but by no means all, will show signs of mild colic. Horses suffering from back pain may display similar signs.

Unravelling the cause of the issue in these horses can be complex, time-consuming and expensive. The vital thing, which doesn’t involve any expensive advanced diagnostics, is that the vet talks to the horse’s owner or rider.

It is important to know how long the owner has had the horse and whether his performance and behaviour have changed in that time. It also helps to identify whether there have been any management changes regarding turnout, workload, tack or rider.

It is also worthwhile trying to work out how much of a problem there really is for the horse.

Riders may report that horses with pain coming from either the back or stomach areas are more “backwards” than usual and “slower off the leg”. With both problems, horses that jump may have started stopping uncharacteristically at fences.

The two sources of pain may be separated in that horses with back pain will usually lose condition involving the topline muscle, as a result of it being painful to work correctly. Horses with significant gastric ulceration will have a more general loss of condition, sometimes losing coat lustre and appearing “tucked up”.

An accurate history can also identify how the two conditions differ, as horses with significant stomach ulceration will usually have a reduced appetite and be picky about hard feed. Those with back pain are unlikely to have any alterations in eating habits.

While owners often perceive that bucking may be a clinical sign of gastric ulceration, in my experience this is rarely the case. Back pain is more likely to be significant when horses develop behavioural issues.

Delving deeper

After a history is obtained from the owner, clinical examination is critical in ascertaining the source of the pain.

Thorough palpation of the thoracolumbar spine (the mid section, from wither to croup) and sacroiliac joints, with assessment of reflexes and whether these are normal, reduced, resented or exaggerated, is a cheap and easy way of identifying back pain. The horse should also be viewed in motion at walk and trot, in a straight line and on the lunge, to check for any stiffness or reluctance to bend and to assess for any primary lameness which may be resulting in secondary back pain. Lungeing after the application of a roller or saddle can be useful in some cases, as can seeing the horse ridden — as long as it is safe to do so.

Definitive diagnosis of gastric ulceration is by gastroscopy. This involves inserting a long endoscope up the horse’s nose, into his oesophagus and then down into the stomach. In recent times, longer endoscopes have become more affordable and more widely available. With increased technical expertise on the veterinary surgeon’s part, the diagnosis of stomach ulcers has become commonplace.

Ulcers can affect either the squamous (upper) or glandular (lower) parts of the stomach. Common sites for ulcer development are the squamous mucosa (lining) near the margo plicatus, the separation of the upper and lower parts of the stomach, or at its exit (the pylorus).

In horses with clinical evidence of back pain upon palpation, radiography is simple and readily available. With the evolution of digital radiography, it is now possible to obtain high-quality images of the thoracolumbar spine even with portable systems in all but the very largest horses. Nuclear scintigraphy (bone scanning) and ultrasonography are available as more advanced imaging techniques if required.

Honest opinion

A practical and cost-effective approach is first to obtain a full history of the horse before performing a full clinical examination and gastroscopy.

The thoracolumbar spine can then be radiographed, if required, while the horse is sedated. If significant gastric ulceration is seen, this should be treated in the first instance.

It is important to carry out the procedures in this order. If gastric ulceration is detected, then any treatment of suspected back pain with non-steroidal anti-inflammatory medication (NSAIDs) should be avoided as it will make gastric ulceration worse.

As a final thought, it is important not to over-diagnose gastric ulceration or the presence of disease in the back such as kissing spines. To add to an already confusing picture, many horses performing to their owners’ expectations may have evidence of both mild gastric ulceration and radiographic evidence of kissing spines — neither of which appear to be causing a clinical problem. Vets with access to modern imaging equipment must be honest about the likely clinical relevance of any abnormalities found and advise their clients accordingly.

Common practice in the not-so-distant past was not to feed any roughage on the day of competition. How many of these horses had stomach ulcers and carried on regardless? In addition, radiography of the horse’s back was not practical or possible outside of large referral hospitals until relatively recently. Even then it was limited. How many horses just got on with the job, despite having kissing spines or dorsal articular facet joint osteoarthritis?

A lot, I suspect, as many must do today. Some horses are stoic to a fault, particularly the real athletes who just keep going. Only when there is a serious problem or something tips the balance do these horses stop performing and find themselves at the vet’s.

Ref Horse & Hound; 2 November 2017