Intracanalicular injection of N-acetylcysteine as adjunctive therapy for the treatment of canine sialoceles: 25 cases.

Objective: To describe intracanalicular injection of 10% N-acetylcysteine (IINAC) as adjunctive treatment for sialoceles in dogs.

Animals: 25 client-owned dogs.

Procedures: Hard copy medical records at 2 veterinary ophthalmology practices were searched to identify dogs that underwent IINAC for treatment of sialoceles from January 2000 to December 2017. Signalment, affected salivary gland, clinical signs, duration of signs, other treatments administered, diagnostic tests performed, anesthetic approach, N-acetylcysteine volume administered, complications, follow-up time, and recurrence of sialoceles were recorded. Descriptive statistics were reported.

Results: Boxers and mixed-breed dogs were most commonly represented. Subjectively decreased globe retropulsion and conjunctival or periorbital swelling (23/25 [92%] dogs each) were the most common clinical signs, with no vision deficits in any patient. The zygomatic gland was mainly affected (23/25 [92%] dogs), followed by parotid and mandibular glands (1 [4%] dog each). The condition was unilateral in 22 (88%) dogs. Ultrasonography (19/25 [76%] dogs), MRI (14 [56%]), fine-needle aspiration (20 [80%]), and biopsy (4 [16%]) were performed; however, the condition was deemed idiopathic in 22 (88%) dogs. Most IINACs were performed with local anesthesia (median volume, 5 mL/gland; range, 1.5 to 9 mL). No complications were identified. Other treatments included antimicrobials and anti-inflammatories. Mean follow-up time was 18.8 months. All recurrences (5/23 [22%] dogs) were controlled with medical management.