Septic sialoadenitis in equids: a retrospective study of 18 cases (1998-2010).

Authors: Kilcoyne I, Watson J L, Spier S J, Whitcomb M B, Vaughan B

Journal: Equine veterinary journal

DOI: 10.1111/evj.12228 PubMed: 24417543Log in to save

Summary

Septic sialoadenitis remains an uncommon but clinically significant condition in horses, characterised by salivary gland infection that causes marked pain, reduced appetite and difficulty swallowing. This retrospective analysis of 18 cases diagnosed between 1998 and 2010 at UC Davis examined the underlying causes, diagnostic approaches and treatment outcomes, finding that the parotid gland was affected twice as frequently as the mandibular gland and that ultrasonography effectively differentiated between the two. Notably, 93% of horses presenting with septic sialoadenitis had concurrent dental or oral abnormalities, whilst one-third developed sialoliths; bacterial cultures consistently isolated *Fusobacterium* species alongside mixed aerobic and anaerobic organisms, emphasising the polymicrobial nature of these infections. With appropriate treatment, 83% of cases resolved successfully, though prognosis should be guarded in older animals (mean age 17.7 years), making early recognition and empirical anaerobic coverage essential whilst awaiting culture results. For practitioners, this work underscores the importance of thorough intraoral examination in cases of salivary gland swelling, recognition of the dental–sialoadenitis link, and aggressive broad-spectrum antimicrobial therapy as first-line management pending sensitivity data.

Read the full abstract on PubMed

Practical Takeaways

•Septic sialoadenitis should be suspected in older horses presenting with salivary gland swelling and inappetence; ultrasound effectively differentiates parotid from mandibular involvement
•Dental disease is a primary risk factor—perform thorough oral examination and address underlying dental abnormalities in all suspected cases
•Treat empirically for anaerobic infection (Fusobacterium species) in all cases until culture results available; prognosis is good (>80%) with appropriate antimicrobial therapy

Key Findings

•18 equids diagnosed with septic sialoadenitis: 11 parotid gland cases, 7 mandibular gland cases, age range 4-30 years (mean 17.7)
•93.3% of equids undergoing complete oral examination had concurrent dental or oral abnormalities
•33.3% of cases (6/18) had sialolith formation; all 9 cultured cases yielded Fusobacterium sp. with mixed aerobic and anaerobic bacteria
•83.3% infection resolution rate with appropriate treatment; 11.1% required euthanasia

Conditions Studied

septic sialoadenitisparotid gland infectionmandibular salivary gland infectionsialolithiasisdental disease

Related References

Partial parotid sialoadenectomy in a horse with parotid ductal carcinoma: Surgical description and case report.

Zetterström Sandra M, Matz Brad M, Neto Rachel L A L T, Lindley Stephanie E S, Cole Robert C, Wilhite Ray, Boone Lindsey H(2022)Veterinary surgery : VS

Historical and clinical features of 200 cases of equine sinus disease.

Dixon P M, Parkin T D, Collins N, Hawkes C, Townsend N B, Fisher G, Ealey R, Barakzai S Z(2011)The Veterinary record

Paranasal sinus cysts in the horse: Complications related to their presence and surgical treatment in 37 cases.

Fenner M F, Verwilghen D, Townsend N, Simhofer H, Schwarzer J, Zani D D, Bienert-Zeit A(2019)Equine veterinary journal

Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): ancillary diagnostic findings and involvement of the various sinus compartments.

Dixon P M, Parkin T D, Collins N, Hawkes C, Townsend N, Tremaine W H, Fisher G, Ealey R, Barakzai S Z(2012)Equine veterinary journal

Diagnosis and treatment of confirmed and suspected primary hyperparathyroidism in equids: 17 cases (1999-2016).

Gorenberg E B, Johnson A L, Magdesian K G, Bertin F-R, Costa L R R, Theelen M J P, Durward-Akhurst S A, Cruz Villagrán C, Carslake H, Frank N, Tomlinson J E(2020)Equine veterinary journal