title: Salivary gland enlargement and sialorrhoea in dogs with spirocercosis: a retrospective and prospective study of 298 cases.
abstract: This longitudinal cross-sectional clinical study investigated the incidence of sialorrhoea in  dogs with spirocercosis and determined whether breed, body weight and the extent of the  oesophageal involvement was associated with this presentation. A retrospective analysis was  performed on the medical records of 233 dogs and information pertaining to 65 dogs was  collected as part of a prospective study. All the animals were client-owned. Patients from the  retrospective study underwent thoracic radiography or oesophageal endoscopy to diagnose  and characterise the infection and were placed on therapy with a macrocyclic lactone, whereas  the patients in the prospective study had both radiography and endoscopy routinely performed  and biopsies of the oesophageal nodules collected where possible. Tru-cut biopsies of affected  salivary glands were taken in 10 of 13 patients demonstrating clinical signs of sialorrhoea and  salivary gland enlargement. The entire salivary gland was sectioned in an additional three  dogs with spirocercosis and no sialorrhoea that were presented for post mortem examination.  Sialorrhoea was present in 33/298 cases (11%). Fox terrier breeds were over-represented in the  patients with sialorrhoea, comprising 36% of cases, whereas they only comprised 1.5% of the  patients without sialorrhoea (p &lt; 0.001, chi squared test) and 5% of the combined group. Dogs  weighing 12 kg or less were significantly over-represented in the sialorrhoea group, 69% versus 19.5% (p &lt; 0.001, chi square test). Age was not significantly different between the two groups  (p &lt; 0.08, Mann-Whitney test). The number of oesophageal nodules per case was significantly  higher in the non-sialorrhoea cases (p = 0.048, Mann-Whitney test). The prevalence of distal  oesophageal and lower oesophageal sphincter involvement, and neoplastic transformation of  the nodules were not statistically different between the two groups. None of the fox terriers  in either group showed neoplastic transformation of the parasitic nodules even though they  were over-represented as a breed. Mandibular salivary glands were affected in 86% of cases  showing sialorrhoea. Histopathology revealed acinar hyperplasia in all cases with concurrent  necrosis detected in only two cases.Sialorrhoea and salivary gland enlargement has an incidence of 11% (33/298 cases) in canine  spirocercosis. Small breeds (≤ 12 kg) and particularly fox terrier breeds are over-represented  in the group demonstrating sialorrhoea and this appeared to be the only risk factor.The conclusion was that sialorrhoea secondary to canine spirocercosis occurs frequently and  its presence should prompt further investigation for oesophageal and gastro-intestinal disease.  Severely affected patients can be managed with phenobarbitone to control the dysphagia in  addition to the routine macrocyclic lactones treatment.
authors: Department of Companion Animal, Clinical Studies, University of Pretoria, South Africa. liesevdm@valleyfarmvet.co.za
authors: Liesel L
authors: LL
authors: van der Merwe
authors: Jevan
authors: J
authors: Christie
authors: Sarah J
authors: SJ
authors: Clift
authors: Eran
authors: E
authors: Dvir
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000453:epidemiology / Q000469:parasitology / Q000473:pathology*; D004285:Dogs; D015994:Incidence; D008137:Longitudinal Studies; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D012469:Salivary Glands / Q000473:pathology*; D012798:Sialorrhea / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*; D013019:South Africa / Q000453:epidemiology; D017205:Spirurida Infections / Q000150:complications / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D013802:Thelazioidea