Sialolithiasis in horses: A retrospective study of 25 cases (2002-2013). This study evaluated outcomes of surgical treatment of equine sialolithiasis, highlighting cases involving the proximal parotid salivary duct.  Ultrasonography confirmed the diagnosis of sialolithiasis in all cases in which there was no radiographic evidence of a sialolith.  All cases of proximal parotid duct sialolithiasis required transcutaneous removal.  A longer duration of illness was observed in cases of proximal parotid duct sialolithiasis compared with cases involving the distal parotid duct, and in cases requiring transcutaneous removal compared with cases requiring transoral removal.  Recurrence of sialolithiasis was documented in 24% of cases, all of which were located in the distal parotid duct. 
Sialolithiasis
Ultrasonography confirmed the diagnosis of sialolithiasis in all cases in which there was no radiographic evidence of a sialolith. 
Ultrasonography