Finding foreign bodies in horses — and how to act *H&H VIP*

  • When Katy Eley’s gelding Viva developed dysphagia (difficulty in swallowing), she brought him to us at Pool House Equine Clinic. Viva seemed otherwise bright and had a normal temperature, but he was progressively eating both hay and hard feed more slowly — something very unusual for him as he usually had a good appetite.

    The mouth is the first place a vet will examine in cases of dysphagia, as a likely cause is a dental issue such as a fractured molar or an overgrown tooth hook (edge) that traumatises the cheek and causes a painful ulcer. In other cases, food, a thorn or even a small fragment of wood lodged between the teeth can cause problems.

    Lesion after a thorn was expelled

    When Viva arrived, the clinicians conducted a thorough examination of his mouth using a speculum. While his teeth appeared to be in good condition, it was noted that a large swelling at the back of his throat was pushing his larynx to one side.

    A small quantity of fresh blood was also present in his mouth.

    Despite there being no obvious wound or foreign body, palpation of Viva’s soft palate produced a pronounced pain response. Inspection of his mouth and pharynx with an endoscope failed to throw any new light on the case.

    It was decided at this point to investigate further by performing a radiographic study of Viva’s head. The X-rays revealed a section of wire embedded at the very back of his mouth. The wire was entirely within the soft palate, which explained why it was not visible on the previous close inspection of the oral cavity. The fact it had penetrated so deeply into the tissues also meant that not even the skilled vets could extract it, even when armed with a pair of forceps.

    A surgical laser was used to incise the soft palate; the wire was extracted under endoscopic and radiographic guidance.

    Surgeon Jonathan Withers, assisted by two of the clinic vets, Marco Marcatili and Federica Cantatore, used a surgical laser to incise the soft palate and was then able to extract the wire under endoscopic and radiographic guidance. The wire seemed to have travelled within the palate, entering on the right side and migrating to the left.

    A small piece of wire had penetrated deeply into the tissues

    Once the wire was removed, Viva made a speedy recovery.

    Down the hatch

    Horses are fastidious eaters with extremely delicate, mobile lips that allow them to carefully pick out material that should not be swallowed. As a result, oral foreign bodies are rare.

    When they do occur, however, they can have potentially life- threatening consequences. If left in place, the material will cause swelling, abscessation, pain and eventually septicaemia.

    With the patient unable to tell us exactly where it hurts, finding the source of pain that is causing dysphagia can be difficult and may involve exhaustive investigation; after all, the possible causes of a horse losing his appetite are many and varied. The fact that the oral cavity of the horse is so long and narrow further complicates matters — it is physically challenging to access areas such as the soft palate in which material can become lodged.

    Ingested netting or string will usually pass through the intestinal tract without complication.

    If you suspect that your horse has swallowed some, however, monitor him closely for signs of illness, fever, abnormal behaviour, poor appetite or colic.

    When dogs, or, more commonly, cats, ingest such material, the main concern
    is that the object will become caught in the passage through their digestive tract and cause serious damage. Fortunately, this is unlikely to occur in horses, since the string would have to be exceptionally long to bind and perforate the intestines. As a precaution, however, it is good practice to check any forage for baling twine to reduce the likelihood of your horse ingesting or becoming entangled in strings.

    Sheet nail in foot

    Eye contact

    Anything that is not supposed to be in or around the eye can be described as a foreign body.

    Hay and grass, but also wood, thorns and seeds, are common. The material can be sitting on the surface of the eyeball, embedded in the eyelids/conjunctiva or trapped under the third eyelid (a favourite of grass seeds). An ocular foreign body can be irritating and sometimes very painful, and in the worst-case scenario may penetrate the eyeball itself. Commonly, the object will lead to the formation of an ulcer on the cornea (the surface of the eye).

    Closed and swollen eyelids, with an overflow of tears on the affected side that leave the face wet, will point to presence of a foreign body. Because of the profuse tears and the spasm in the eyelids, it is not usually possible to identify whether there is matter in the eye without the aid of sedation, regional nerve blocks and an ophthalmoscope.

    If by chance you see something, wait for your vet and do not try to remove it. Attempts to remove it incorrectly, especially if the item is embedded in the eyeball itself, could cause further damage and may even lead to the structure of the eye collapsing — a development that may result in loss of the eye.

    Foreign body penetration of the skin is a common scenario. Blackthorns from browsing in hedgerows and splinters of wood from rubbing on fencing are just two common culprits.

    The body will usually attempt to “wall off ” the invader, which results in a hard lump developing in the skin. The lump is painful to the touch and will often progress to an abscess containing pus.

    Ultrasonographic examination of a suspect lump will greatly help with determining the presence of a foreign body. As with a foot abscess, treatment with antibiotics alone — while possibly reducing the swelling temporarily — will not resolve it. Instead, hot poultices should be applied to the area several times daily, encouraging the abscess to come to a point and expel the
    intruder upon bursting. Alternatively, your vet may opt to lance the swelling and flush out the contents along with the foreign body, after which healing should be uneventful.

    There’s something afoot…

    Stones, wood chips, wire and nails are the most common foreign bodies to penetrate the sole. If penetration is superficial, it will be a case of removing the object, cleaning the wound and keeping it protected with bandaging, along with antibiotic treatment, until the tissues have healed.

    A deeper puncture wound can be a wholly different matter, as there is a grave risk that one or more of the synovial structures underneath the frog (the coffin joint, the navicular bursa and digital sheath) have been breached — a life-threatening condition which should be considered an emergency.

    Lameness is the most common clinical sign of a puncture wound to the hoof. In addition, the affected foot is usually warmer and shows a raised digital pulse. If the infection is well-established, swelling of the lower limb can be present along with drainage from the site of injury.

    If the foreign body is still present in the foot, you are advised not to remove it while you wait for the vet to arrive. Instead, keep your horse still, lift the affected foot off the ground or wrap it in towels — all in an effort to prevent the object from being pushed any deeper.

    Leaving the object in place allows for X-raying of the foot to confirm the path taken by the object and the depth to which it has penetrated. This can greatly increase the speed of decision-making regarding whether the object is likely to have entered any synovial structures. Where synovial involvement is suspected, speed is of the essence.

    Ref: Horse & Hound; 5 October