Sialocele in a cat and its surgical management

Introduction

Sialocele or salivary mucocele (Honey cyst) is accumulation of saliva in the subcutaneous tissue subsequently causing tissue reaction to the saliva. The cause often remains obscure although trauma has been implicated. Mucocele occurs most commonly in the inframandibular space (cervical) but can be located orally (ranula) or in the pharyngeal wall. It is an uncommon but important condition in feline when saliva leaks from a damaged salivary gland or duct and accumulates in surrounding tissues, forming a fluctuant, walled-off collection of mucoid fluid (Bassanino et al. 2019) [1] . The cats possess five pairs of major salivary glands: parotid, mandibular, sublingual, molar (buccal), and zygomatic. Mucoceles have been reported with most of these (except the molar in some older reviews), though the sublingual and mandibular glands are most frequently implicated (Kiefer and Garret, 2007) [2] . The leakage typically stems from trauma to the gland or duct, though the exact cause is often idiopathic (MacPhail, 2013) [3] . Potential inciting factors include bite wounds, foreign body penetration, choke collars, or sudden neck movements. Unlike true cysts lined by epithelium, mucoceles are pseudocysts surrounded by inflammatory granulation tissue. The accumulated saliva triggers inflammation, which can lead to further leakage and enlargement of the mass (Tsioli et al. 2015) [4] .

Case History and Observations

A one-and-half year old, intact male, indoor Persian cat weighing 3.2kg was presented with a history of selective feeding, salivation and a swelling noticed below the tongue since three days. The cat was vaccinated and dewormed regularly and fed with commercial diet. On physical examination all the vital parameters were within the normal range. Clinical examination of the oral cavity revealed a small gooseberry sized mass noticed below the tongue (Fig. 1). The mass was red in colour and palpation revealed fluctuation and confirmed sialocele. Blood samples were collected for haemato-biochemical parameters and revealed normal.

Treatment and Discussion

Sialoadenectomy was planned and every attempt was made to minimize stress to the cat prior to surgery. The cat was anaesthetized using injection Xylazine 0.5mg/kg and Ketamine 5mg/kg bd wt (cocktail) intramuscularly respectively. The cat was positioned in sternal recumbency and placed a pad under the neck to rotate the ventral aspect dorsally and fix the neck in an extended position. The sublingual salivary gland was excised (Fig. 2) and marsupialization was done using 2.0 PGA and a simple interrupted pattern. The animal was administered with antibiotics cefodoxime and analgesic meloxicam intravenously respectively. Post operatively adviced the owner to apply E.coller and administer syrup cepodoxime @ 10mg per kg and analgesic syrup meloxicam @ 0.01 mg/kg along with supportive therapy which include soft diet. No intraoperative complications were reported and the cat was recovered uneventfully. Sialocoeles in cats are uncommon, with only a limited number of described in veterinary literatures (Ritter and Stanley, 2018) [6] . Spangler and Culbertson (1991) [5] reported that dogs had two times the occurrence of sialocoele than cats. Sialocoele can affect cats at any age with no sex or breed predisposition. Similarly to dogs, the most common salivary gland affected in cats is the sublingual-mandibular glandduct complex, which could result in sublingual, cervical or pharyngeal sialocele (Bassanino et al. 2019) [1] . The long-term prognosis after appropriate surgical management is excellent. Most cats return to normal function quickly, with resolution of clinical signs and no recurrence when the gland-duct complex is fully excised. The sialocele may be differentiated from the abscess, neoplasia, hematoma, foreign body granuloma, sialadenitis, lymph node enlargement, edema, pharyngeal remnant cyst, salivary gland tumour, necrotizing sialometaplasia or salivary gland duct obstruction from a sialolith by doing fine needle aspiration (FNA) analysis. Complications are uncommon but may include seroma (Tsioli et al. 2015) [4] (fluid accumulation at the site), infection, temporary nerve damage or bleeding, recurrence (if excision is incomplete). Cats do not typically develop xerostomia (dry mouth) even after mandibular/sublingual removal. Since most cases are idiopathic, prevention is challenging. Avoid known trauma risks (e.g., choke collars). Early and regular veterinary evaluation of any neck or oral cavity is recommended. Successful management of salivary mucocele in cats hinges on accurate diagnosis via aspiration and imaging, followed by targeted surgical intervention-primarily sialoadenectomy of the affected gland(s) combined with marsupialization for ranulas. This approach yields rapid resolution, minimal complications, and excellent long-term outcomes (Spangler and Culbertson 1991; Langley-Hobbs, 2014) [5,7] . The same procedure was followed for the above case and the animal has an uneventful recovery.

References

1. Bassanino J, Palierne S, Blondel M, Reynolds BS. Sublingual sialocele in a cat. JFMS Open Reports. 2019;5(1):2055116919833249.
2. Kiefer KM, Garret JD. Salivary mucoceles in cats: a retrospective study of seven cases. Veterinary Medicine. 2007;102:582-585.
3. MacPhail CM. Disorders of the salivary gland. In: Monnet E, editor. Small animal soft tissue surgery. Oxford: Wiley-Blackwell; 2013. p. 299-303.
4. Tsioli V, Brellou G, Siziopkou C, et al. Sialocele in the cat: a report of 2 cases. Journal of the Hellenic Veterinary Medical Society. 2015;66:141-146.
5. Spangler WL, Culbertson MR. Salivary gland disease in dogs and cats: 245 cases (1985-1988). Journal of the American Veterinary Medical Association. 1991;198:465-469.
6. Ritter MJ, Stanley BJ. Salivary glands. In: Tobias KM, Johnston SA, editors. Veterinary surgery: small animal. 2nd ed. St. Louis (MO): Elsevier/Saunders; 2018. p. 1653-1663.
7. Langley-Hobbs SJ. Head. In: Langley-Hobbs SJ, Demetriou JL, Ladlow JF, editors. Feline soft tissue and general surgery. St. Louis (MO): Saunders Elsevier; 2014. p. 571-586.