Indications of Diathermy in Veterinary Medicine

1. Hemostasis / Coagulation

• Cauterizes small to large blood vessels simultaneously, keeping the surgical field clear and reducing operative time.
• Bipolar vessel-sealing devices (e.g., LigaSure) can seal vessels up to 7 mm in diameter.
• Applied in routine soft tissue surgeries: ovariohysterectomy (spay), castration, mass excisions, exploratory laparotomies, and thoracic surgeries.

2. Tissue Cutting and Dissection

• Cutting mode vaporizes tissue at ~100°C, producing a clean incision with concurrent hemostasis.
• Reduces total blood loss significantly over sharp dissection alone.
• Useful in liver surgery, splenectomy, and any organ resection where bleeding control is challenging.

3. Tumor/Neoplasm Removal and Ablation

• Excision of cutaneous and subcutaneous tumors (e.g., mast cell tumors, fibrosarcomas, melanomas) in dogs, cats, and equines.
• Destruction (fulguration/ablation) of small, superficial skin tumors where complete excision is not feasible.
• Equine sarcoids and other skin lesions on horses are a common specific indication.
• Used in endoscopic tumor debulking (e.g., nasal or laryngeal tumors) via electrosurgical snares or loops.

4. Dermatologic / Skin Lesions

• Removal of warts (papillomas), skin tags (acrochordons), sebaceous cysts, and granulomas.
• Treatment of pyogenic granulomas and epidermal inclusion cysts.
• Fulguration of fungal plaques or chronic skin lesions in exotic species.

5. Ophthalmic Surgery

• Used for hemostasis during enucleation and eyelid surgeries.
• Correction of entropion/ectropion - electrosurgical techniques can reshape lid margins.
• Distichiasis treatment (aberrant eyelash removal) via electro-epilation.

6. Oral and Dental Surgery

• Excision of epulis, oral tumors, and gingival hyperplasia in dogs and cats.
• Hemostasis during tooth extractions in large animals.
• Tonsillectomy and soft palate resection (staphylectomy) in brachycephalic breeds - this is one of the most frequent electrosurgical indications in small animal practice.

7. Urogenital Surgery

• Partial or total prostatectomy, cystotomy hemostasis.
• Bladder mass resection or fulguration via cystoscopy.
• Vaginal and vulvar mass excision.

8. Fulguration (Destructive Coagulation)

• Treatment of superficial bladder tumors (transitional cell carcinoma) via cystoscopy in dogs.
• Destruction of rectal/perianal lesions.
• Perianal fistulas (anal furunculosis) in German Shepherds - electrosurgical fulguration was a primary treatment before immunosuppressive therapy became standard.

9. Gastrointestinal Endoscopy

• Snare polypectomy: removal of colorectal or gastric polyps via electrosurgical snare.
• Endoscopic hemostasis of gastrointestinal bleeding.
• Stricture dilation and sphincterotomy in specialty settings.

10. Equine-Specific Uses

• Standing sedation surgery using diathermy for perineal, skin, and upper airway lesions.
• Laser/electrosurgical treatment of ethmoid hematomas via endoscopy.
• Treatment of sarcoids, squamous cell carcinomas, and other skin tumors.
• Laryngeal surgery (laryngeal lateralization / tie-back procedure hemostasis).

11. Physiotherapy (Shortwave Diathermy)

• Indicated for musculoskeletal pain, muscle spasm, joint stiffness, and tendon/ligament injuries in large animals (horses, cattle).
• Used post-operatively to promote tissue healing and reduce inflammation.
• Contraindicated over implants, growth plates in young animals, and neoplastic tissue.

Types Used in Veterinary Practice

Key Contraindications (for context)

• Patients with cardiac pacemakers (use bipolar only, if at all)
• Near metal implants or orthopedic hardware (risk of current concentration/burns)
• Wet or alcohol-soaked surgical fields (fire risk)
• Use over pressure necrosis sites or poorly perfused tissue

Dentigerous Cyst in Veterinary Science

Definition

Pathogenesis

1. During normal tooth development, the tooth crown is surrounded by a multilayered follicular sac (reduced enamel epithelium).
2. If the tooth fails to erupt - due to impaction, crowding, or developmental abnormality - this follicular sac can undergo cystic transformation.
3. Fluid accumulates within the follicle, progressively expanding the cyst.
4. As it enlarges, it exerts pressure on surrounding bone, causing pressure atrophy and bone resorption.
5. The expanding cyst destroys periodontal support of adjacent teeth, can resorb roots of neighboring teeth, and ultimately weakens the jaw - potentially causing pathological fracture.

Species Affected

Dogs (Most Common Small Animal)

• The most common odontogenic cyst in dogs, as noted by Veterinary Dentistry Specialists.
• Brachycephalic breeds are especially predisposed: Boston Terriers, Boxers, Pugs, Shih Tzus - likely due to skull shape and dental crowding impairing normal tooth eruption.
• Most commonly affects the mandibular first premolar, followed by mandibular third molar, mandibular incisors, and canine teeth.
• Any breed can be affected; small breeds overall are more predisposed.

Cats

• Reported but significantly less common than in dogs.

Horses (Equine - Distinct Presentation)

• In horses, true dentigerous cysts are defined as a cystic dilation of the dental follicle around an unerupted tooth within the dental arcades - confirmed by an epithelial lining and associated unerupted tooth on imaging and histology.
• Importantly, many historical reports of "dentigerous cysts" in horses actually describe periauricular temporal teratomas - a distinct developmental disorder from aberrant migration of neural crest-derived ectomesenchymal stem cells from the first branchial arch, resulting in dental tissue enclosed in a cystic structure in the parietotemporal region (near the base of the ear). Per a 2025 equine retrospective study, "temporal teratomas should be considered a separate lesion to dentigerous cysts because they originate outside of the normal dental arcade."
• True equine dentigerous cysts are associated with unerupted teeth within the maxillary or mandibular arcades, presenting as well-defined unilocular to multilocular radiolucencies with a sclerotic border.

Clinical Signs

Diagnosis

• Oral radiography is the primary diagnostic tool. Radiographically, a dentigerous cyst appears as a circular/ovoid, well-defined radiolucency with a corticated border, surrounding the crown of an unerupted tooth.
• A cyst can encompass a single tooth or, in severe cases, multiple teeth and extensive bone.
• Histopathology of the cyst lining is required for definitive diagnosis - it shows a thin, non-keratinized epithelial lining (2-4 layers of cuboidal/squamous cells) attached at the cementoenamel junction, within a fibrous wall. This also rules out more aggressive lesions (ameloblastoma, squamous cell carcinoma) that can arise within dentigerous cysts.

Treatment

• Early intervention is key - described as "100% avoidable" when unerupted teeth are identified and treated promptly (Hale, DVM, FAVD).
• Extraction of the unerupted tooth + complete surgical excision (en bloc removal) of the cyst lining is the treatment of choice and is curative when performed early.
• Any adjacent teeth that have lost periodontal support or suffered root resorption must also be extracted.
• In advanced cases with significant bone loss, a bone graft may be required to fill the defect.
• All excised cyst tissue should be submitted for histopathology to confirm diagnosis and rule out malignant transformation.
• Annual radiographic monitoring post-treatment to check for recurrence.

Prevention

• Perform a thorough oral examination and tooth count at 6 months of age (spay/neuter visit) - the time when adult teeth should be fully erupted.
• Any "missing" tooth should be investigated with intraoral radiographs - never assume a tooth is simply absent.
• In high-risk brachycephalic breeds (especially Boxers), full-mouth radiographs are recommended even when the tooth count appears normal, as cysts can be present behind apparently normal-looking gingiva.

Key Points Summary

• A dentigerous cyst is a developmental, fluid-filled odontogenic cyst surrounding the crown of an unerupted tooth, arising from the reduced enamel epithelium.
• Most common odontogenic cyst in dogs; rare in cats; distinct considerations in horses.
• Brachycephalic breeds are most at risk.
• Mandibular first premolar is the most frequently affected tooth in dogs.
• Capable of causing progressive, irreversible bone destruction and pathological fracture if left untreated.
• Completely preventable with early detection and extraction of unerupted teeth.
• Definitive diagnosis requires histopathology of the cyst wall.
• Treatment is en bloc surgical removal - curative when performed early.