Salivary Fistula
Description
A salivary fistula can result from injury to any salivary gland, but most commonly the parotid. Fistulas forming from other glands is uncommon.
Injury may be due to:
- Traumatic wound to the face e.g. bite wound
- Abscess drainage
- Iatrogenic rupture following prior surgery in the region
- Exopthalmus is the most likely cause of zygomatic duct injury
The continuous flow of saliva prevents healing and therefore a fistula develops
When a salivary duct injury occurs due to trauma on the face, this results in a fistula being created which will cause discharge of saliva onto the face. Discharge from the gland may be noticably worse before or during feeding.
Diagnosis
Clinical Signs
- Fistula visible over parotid region, or located upon clinical examination
- Discharge from fistula (must be differentiated from a draining sinus) resulting in a visibly wet face
- History or current presence of a wound over the parotid region
Differentiation from a draining sinus by assessment of the discharge- salivary fistula will discharge a golden or blood tinged saliva, which will be viscous and 'stringy' in appearance. Mucous can be identified in this by use of periodic acid-schiff stain.
Treatment
Surgical ligation of the duct or complete removal of the gland is neccesary
References
Merck & Co (2008) The Merck Veterinary Manual