Dogs are the most likely to experience stick penetrations, probably due to their tendency to leap through the woods with their mouths open or by chasing sticks thrown by their owners. Less frequently cats will sustain penetrating injuries to the mouth and pharynx. Objects can be lodged in the pharynx, nasal cavity, retropharyngeal tissues, neck, shoulder or brisket. Some of the linear objects may migrate and cause issues at distant sites over time. Penetrating stick injuries are sustained fairly sporadically, but can be quite spectacular in presentation at times, causing significant discomfort to the animal and distress to the owner.

There does not appear to be a typical breed or predisposing age for this condition. The average age is around 5–6 years, medium- and large-size dogs, and possibly a higher incidence in males. Animals with stick penetration tend to present in two separate and quite clinically distinct categories.

Presenting Signs

Acute

The presenting signs of an acute case (this has been termed as less than 7 days) include:

 Obvious non-oral entrance wound, with object visible in some cases

 Oral or nasal irritation. Dogs can initially appear maddened

 Reluctance to having the jaws manipulated open

 Hypersalivation

 Blood-tinged saliva

 Dysphagia

 Gagging

 Stertorous pharyngeal noise, which may be accompanied by dyspnoea

 Epistaxis

 Exophthalmos and periorbital swelling

 Ocular discharge

 Lameness (if cervical or limb involvement)

Chronic

Over 75% of cases are chronic - from weeks to months following original insult. Following initial impalement, the stick may break off, or be only partially removed. Skin, and particularly oropharyngeal mucosa, can heal quickly, thus concealing the original entry site. Additionally, there is not always an accurate history of trauma. Once settled in the tissues, the heavily contaminated foreign body can then abscess, leading to swelling and a draining tract. If it is wooden, it will develop radio-opacity similar to muscle as it absorbs water. Some of these foreign bodies can also migrate considerable distances. Chronic oropharyngeal stick injuries can therefore be quite variable in their presentation. Animals can demonstrate one or several of the following signs:

 Swelling

 Draining tract. The nature of the discharge can vary from serous, serosanguineous, or purulent

 Lethargy/dullness

 Pain, and sometimes even a change in character

 Difficulty or resentment upon manipulating the jaws open

 Halitosis

 Subcutaneous emphysema

 Lameness, usually a thoracic limb

 Neck pain

 Neurological signs (including quadriparesis)

There have been reports of brain abscessation, atlantoaxial osteomyelitis, quadriparesis from spinal canal migration and pyothorax. We have also seen chronic brachial plexus signs, and thoracic impalements with arrows.

Diagnosis

An accurate history plays a pivotal role in chronic cases. If clinical signs are at all suggestive, owners should be questioned in detail for any possible incident where impalement may have occurred. Sometimes intense questioning will act to jog owners' memory about a possible episode of impalement, and we have had several instances when a family discussion at home has recalled a long-forgotten mishap (e.g., a painful yelp out in the woods). Routine laboratory tests are performed as necessary, the following diagnostics are useful:

 Non-regenerative anaemia. Common, and attributed to the effects of chronic inflammation.

 Oropharyngeal examination. This should be done carefully and thoroughly under anaesthesia, using probes, and allowing plenty of time. Concentrate on the sublingual tissues (both sides), the piriform recesses, the dorsal pharynx (dorsal to the oesophagus, with rostral retraction of the soft palate), caudal to the tonsillar crypts, and the roof of the mouth (sometimes sticks can get jammed across the two dental arcades of the maxilla).

 Oesophageal endoscopy should always be performed, as the stick may have penetrated through the proximal oesophageal wall, which can negatively impact prognosis. Endoscopy should always include a retroflexed view of the choanae.

 Radiography. Typically, plain radiography is unrewarding. However, radiographs will detect other conditions such as mediastinitis, pulmonary or pleural involvement, and also will identify metallic or other radio-opaque foreign bodies.

 Computed tomography (CT) and magnetic resonance imaging (MRI) have revolutionised our diagnostic capabilities when hunting for foreign bodies. The sensitivities of these imaging tools, especially with contrast agents and other enhancing modes, along with the technology to reformat images in three dimensions, make either CT or MRI almost mandatory. MRI is also quite sensitive in visualising the inflammation around the foreign body. These tools also greatly facilitate the surgery.

 Sinography. This tool, preferably with CT but also with fluoroscopy, can prove quite useful if a draining tract exists. To maximise the likelihood of the iodinated contrast highlighting the filling defect around the foreign body, it is important to perform the test when the animal has an obvious draining tract.

 Ultrasonography can locate a variety of foreign bodies, and is recommended if advanced imaging tools are not available.

In rare circumstances, cases will require more specific work-up relevant to the clinical presentation and are not discussed here, e.g., myelography for upper neurological presentations.

Treatment

Almost all oropharyngeal stick injuries should be explored surgically, due to the degree of contamination that occurs when the stick is driven into the tissues from the oral cavity. A possible exception to this statement may be a per-acutely presented oral stick injury that can be removed cleanly through the mouth, without debris (such as bark) being left behind. In this situation the oral and retropharyngeal tissues may heal well by just flushing the defect and leaving the mucosa unsutured. In such a situation, the owners would need to be educated about the possibility of abscessation.

The approach to acute penetrations is usually directly over the stick, if palpable, or the ventral midline if non-palpable. Imaging may further aid the surgical approach. Orbital foreign bodies are usually retrieved via a modified lateral orbitotomy, through the zygomatic arch. Once the skin has been opened and explored down to the stick in acute injuries, the resulting wound can be copiously flushed, and as much bark or other debris removed as possible. The external wound can either be left open (and subsequently closed as a delayed primary or secondary closure) or be closed with drains. The oral/pharyngeal mucosa should be closed if possible, but only if drainage is provided to the retropharyngeal tissues. Due to a poorer prognosis associated with oesophageal penetrations, they are always debrided and closed at our Teaching Hospital, even if the perforation is small. It can sometimes be difficult to suture the caudal pharynx, but sublingual penetrations can readily be closed. The use of closed suction grenades or pumps to provide drainage of the retropharyngeal tissues is strongly recommended, rather than passive drain systems. Be aggressive with acute penetrating injuries, and it will avert subsequent problems associated with chronicity.

With chronic injuries, any draining tract is usually explored by meticulous dissection using probes and catheters. A very generous clip should be performed, extending from mid-thorax to the mandible. The usual approach is through a ventral midline cervical incision. Be prepared not to find the offending object, and educate the owners of this expectation. In the literature, final outcome is not always related to the retrieval of a foreign body. Once the tract is explored, and hopefully a foreign body retrieved (put the champagne on ice), there is usually a very contaminated open wound. A macerated tissue culture is performed at this time. Both aerobic and anaerobic cultures should be undertaken; and with the plant material that has often been festering in the wound, it is prudent to take tissue cultures for Actinomyces and acid-fast organisms such as Nocardiaand Mycobacterium. These results may prove to be useful in the final treatment of this region, and are especially indicated in the event a foreign body is not located. The area can be fairly aggressively debrided (depending on location), and generally managed open for a few days with negative pressure wound therapy or wet-dry dressings, before closing with drains, or allowing to heal by second intention.

Postoperative Course and Expectations

Even once the foreign body is retrieved, the wound is still obviously contaminated or infected, and continued discharge can be a problem in about 25% of cases. Fragmentation may have hindered extraction of all foreign material. Additionally, chronic granulomatous inflammatory tissue has become established and in itself can perpetuate clinical signs of drainage. It is for these reasons that delayed closure or healing by second intention is recommended. Revisional aggressive debridement may be required, and this possibility should be understood by owners.

References

1.  Doran IP, Wright CA, et al. Acute oropharyngeal and esophageal stick injury in forty-one dogs. Veterinary Surgery 2008;37:781–785.

2.  Griffiths LG, Tiruneh R, et al. Oropharyngeal penetrating injuries in 50 dogs: a retrospective study. Veterinary Surgery 2000;29:383–388.

3.  Hartley C, McConnell JF, et al. Wooden orbital foreign body in a Weimaraner. Veterinary Ophthalmology 2007;10:390–393.

4.  Nicholson I, Halfacree Z, et al. Computed tomography as an aid to management of chronic oropharyngeal stick injury in the dog. Journal of Small Animal Practice 2008;49:451–457.

5.  Rayward RM. Acute onset quadriparesis as a sequela to an oropharyngeal stick injury. Journal of Small Animal Practice 2002;43:295–298.