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Pharyngeal Paralysis: Introduction |  |
| Pharyngeal paralysis may be the result of a central or peripheral nervous disorder, or of severe local disease that may cause collapse, obstruction, or malfunction of the pharynx. Of the CNS disorders, rabies (
Rabies: Introduction) is the most important of the viral encephalomyelitides although perhaps not the most frequent. CNS intoxication, lead poisoning, cranial trauma, intracranial abscessation, and tumor formation may also dramatically affect pharyngeal
function in many species. |
| Pharyngeal paralysis of peripheral etiopathogenesis can be the result of pharyngeal trauma or of disease or dysfunction of the pharyngeal adnexa, such as the auditory tube diverticula (guttural pouches) in horses. In many of these cases, the effect on pharyngeal function may not be total paralysis. One-sided lesions (eg, guttural pouch disease) may result in partial pharyngeal malfunction, and the horse may well be able to swallow, although subsequent complications may occur. |
| Clinical Findings and Lesions: |
| In general, pharyngeal paralysis results in profound dysphagia and the oral and nasal return of food and saliva. In most species, pharyngeal collapse occurs; in horses, this may result in respiratory obstruction. Affected animals are at risk of inhalation pneumonia, dehydration, and circulatory and respiratory collapse. Affected animals have a fever, cough, retch, and choke. Pharyngeal paralysis may result in death. |
| In many cases, emergency treatment to provide an airway (eg, tracheostomy) may be essential before any clinical diagnostic techniques can be performed. |
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| Diagnosis: |
| The history and clinical signs are usually enough to indicate pharyngeal malfunction and may indicate total pharyngeal paralysis. Use of clinical pathology and hematology to evaluate hemoconcentration, electrolyte depletion, etc, aid in monitoring and evaluating therapeutic regimens. Serology, radiology, ultrasonography, computed tomography, and MRI, as well as endoscopic examination may all be valuable aids to determine whether the underlying etiology is central or peripheral.
The use of advanced imaging technologies has particular value in evaluating CNS causes of pharyngeal paralysis in small animals. The possibility of rabies must be kept in mind, especially for any necropsy procedures. |
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| Treatment: |
| In general, treatment is symptomatic, ie, anti-inflammatory drugs, antibiotics to control the complications of inhalation pneumonia, local therapy (including draining the pharyngeal abscesses), and the provision of alternative routes of nutrition. In small animals, intubation and, in large animals, rumenotomy and/or esophagotomy and esophageal feeding may be essential. In many cases, the prognosis is poor, and the welfare of the animal should be considered in management of this condition. |
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