Pharyngitis is an inflammatory condition of the walls of the oro- or nasopharynx. Pharyngitis may develop secondary to viral or bacterial infections of the upper respiratory tract, eg, strangles in horses Strangles in Horses Strangles is a highly prevalent infectious disease characterized by upper respiratory tract lymph node abscessation secondary to infection with Streptococcus equi equi. The abbreviated terminology... read more and distemper in dogs Canine Distemper Canine distemper is a highly infectious, systemic, viral disease of dogs that occurs worldwide. Dogs commonly exhibit systemic clinical signs (fever, lethargy, loss of appetite), respiratory... read more .
In most species, a common pharynx is present at times other than deglutition. The unique caudal pharyngeal-laryngeal anatomy of horses shows complete separation of the pharynx into two components, the nasopharynx and the oropharynx. (Also see Pharyngeal Lymphoid Hyperplasia in Horses Pharyngeal Lymphoid Hyperplasia in Horses Pharyngeal lymphoid hyperplasia (PLH) is a common condition of the dorsal pharyngeal wall seen in young horses (1–3 years old). Horses do not have discrete masses of lymphoid tonsillar tissue... read more .)
Clinical Findings of Pharyngitis in Animals
Animals affected with pharyngitis have a normal desire to eat and drink; however, they may have difficulty swallowing and may appear dysphagic. Animals with secondary peripharyngeal cellulitis and abscessation may be acutely dyspneic secondary to pharyngeal obstruction. For example, foals affected with suppurative pharyngitis secondary to abscessation of the retropharyngeal lymph nodes can become acutely dyspneic and require an emergency tracheotomy.
Diagnosis of Pharyngitis in Animals
The diagnosis of pharyngitis can be made with a complete physical examination, radiographic evaluation of the skull, endoscopic evaluation of the pharynx, and microbial cultures of draining abscesses or nasopharyngeal swabs for viral isolation. In small animals, oral pain and resistance to having the mouth opened may indicate retropharyngeal abscessation and the presence of a penetrating foreign body or oral or tonsillar neoplasia. Abnormal pharyngeal tissue should be biopsied and submitted for histopathologic examination to exclude pharyngeal neoplasia. In small animals, oral examination and/or endoscopic examination is the best diagnostic tool for pharyngitis. In large animals, the diagnosis of pharyngitis is easily made by endoscopic examination of the upper respiratory tract.
Treatment of Pharyngitis in Animals
Systemic antimicrobials and anti-inflammatories
Topical application of anti-inflammatories
Bacterial pharyngitis should be treated with systemic antimicrobials based on results of microbial culture and sensitivity testing. Abscesses should be drained and lavaged when appropriate. Viral-induced pharyngitis should be managed with antimicrobials to prevent secondary bacterial infections. Animals affected with either bacterial or viral pharyngitis should be treated with NSAIDs. Pharyngitis secondary to foreign bodies should be resolved with removal of the offending object and effective surgical drainage accompanied by excision of necrotic tissue.
Racehorses affected by pharyngeal lymphoid hyperplasia can be treated with topical and systemic anti-inflammatory agents such as flunixin meglumine, phenylbutazone, or dexamethasone. A commonly used topical anti-inflammatory treatment includes prednisolone, dimethyl sulfoxide, glycerin, and nitrofurazone. Large pharyngeal masses can also be treated with contact diode laser photoablation. Some veterinarians have also anecdotally suggested that hyperimmunization is helpful in managing pharyngeal lymphoid hyperplasia.
Calicivirus infections in cats may cause mild, moderate, or severe ulceration of the oropharyngeal mucosa. Although specific antiviral therapies are not available, affected cats should be treated with systemic antimicrobials to prevent secondary bacterial infection. Animals that cannot maintain their own hydration because of severe mucosal ulceration may require nutritional and electrolyte supplementation either intravenously or by extraoral tube feeding.
Pharyngitis is typically an inflammatory condition.
It is managed primarily with administration of antimicrobials and systemic and topical anti-inflammatories.
For More Information
See also pet health content regarding pharyngitis in cats Pharyngitis in Cats Pharyngitis is inflammation of the walls of the throat (pharynx). It accompanies most upper airway viral and bacterial respiratory infections. Calicivirus infections in cats may cause lesions... read more , dogs Pharyngitis in Dogs Pharyngitis is inflammation of the walls of the throat (pharynx). It accompanies most upper airway viral and bacterial respiratory infections, such as distemper in dogs. Other causes include... read more , and horses Pharyngeal Lymphoid Hyperplasia (Pharyngitis) in Horses Pharyngeal lymphoid hyperplasia is a condition that occurs in young horses (1 to 3 years old). Unlike humans, horses do not have masses of lymphoid tissue that make up tonsils. Instead, there... read more .