Page 249 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

224 CHAPTER 1

VetBooks.ir fractures located more caudally may cause ptyalism, Differential diagnoses
Other causes of dysphagia can include oesophageal
dysphagia and eventually marked halitosis as food
becomes impacted into the fracture site. Horses with
periodontal disease, botulism and other neurologi-
maxillary fractures may have concurrent nasal and/ obstruction, retropharyngeal masses, dental and
or frontal bone fractures (see p. 228). Palpation of the cal conditions. Soft-tissue trauma of the oral cavity,
rostral skull may reveal abnormal movement of the such as tongue laceration, may result in dysphagia
rostral mandibular region, if there are bilateral frac- and halitosis. Dental disease is a more common
tures, or misalignment of the incisors. Examination cause of focal ventral mandibular and rostral facial
of the oral cavity is important, but until further diag- swelling than trauma.
nostic evaluation has been performed the use of an
oral speculum may be contraindicated, with the risk Diagnosis
of further displacement of the fractured bones. The Although neurological deficits are less likely fol-
initial oral examination may therefore be rudimen- lowing mandibular or maxillary fractures than with
tary and superficial. A cheek tooth gag (Fig. 1.417) caudal skull fractures, assessment of cranial nerve
can be used in some cases to open the mouth just (CN) function should be performed early in the
enough to examine and safely palpate structures of investigation of all head trauma. In most cases, radi-
the rostral oral cavity. Equally, a tube gag (Fig. 1.418) ography is used to confirm a diagnosis of mandibu-
can be placed in the interdental space, allowing more lar or maxillary fracture. Laterolateral (Fig. 1.419),
detailed and safe examination of the incisors. laterolateral oblique (Fig. 1.420) and dorsoventral
Oral wounds may be visible, often with accom- views (Fig. 1.421) can all be obtained under seda-
panying haemorrhage and/or food contamination. tion, and may be performed safely in the field. For
Palpation of surrounding bones may reveal crepitus rostral fractures, the cassette or digital plate can
and misalignment synonymous with fractures. be inserted into the oral cavity to allow evaluation
Displaced incisors or laceration of the rostral gingiva of the affected incisor region without superimposi-
should raise the suspicion of a fracture of the ros- tion of the opposing arcade (intraoral oblique view)
tral mandible or premaxilla. In some cases, further (Fig. 1.422). The latter view is particularly useful
inspection using an oral mirror or rigid oral endo- and best performed with a plate protection device
scope may facilitate the diagnosis of such lesions or radiolucent speculum in situ to prevent damage as
further caudally in the mouth. the horse chews.

1.417 1.418

Fig. 1.417 A cheek tooth gag placed between two Fig. 1.418 A tube gag placed in the interdental space
opposing cheek teeth arcades. between the incisors and cheek teeth to allow safe
examination and access to the occlusal surfaces of the
incisors.