URT surgery in small animals

• Primary upper respiratory tract problems

  • Stenotic external nares
  • Relative overlength of the soft palate
  • Relative oversize of the tongue
  • Tracheal hypoplasia/ stenosis
  • Sliding hiatal hernia
• Secondary Upper respiratory problems

  • Relative hypertrophy of the soft palate
  • Tonsilar hypertrophy
  • Everted laryngeal ventricles/ saccules
  • Laryngeal collapse
  • Pharyngeal collapse
  • Glossy-epiglottic mucosa displacement
  • Scrolling of epiglottic cartialge
  • Vomiting/ regurgitation.
• Tracheal Hypoplasia

  Some dogs are born with small tracheas.

  
• Laryngeal collapse

  Stage 1 - laryngeal saccule eversion.

  Stage 2 - medial deviation of the cuneiform cartilage and aryepiglottic collapse.

  Stage 3 - medial deviation of the corniculate process of the arytenoid cartilages or corniculate collapse.
• Rhinoplasty - wedge resection

  Always try to open up the external nostrils when doing BOAS surgery.

  
• Alar fold resection

  Different from the standard wedge resection as it removes the alar fold internally to create a much larger hole. No published work to show one is better than the other.

  
• Surgery of the soft palate - partial staphylectomy

  Almost all of the dogs will need a palate resection. This procedure is cutting a portion of the palate away, bringing it back to the length of the tonsil fossa.

  
• Folded-flap palatoplasty

  Partial thickness incision (inverted U incision), unfold the palate, then can trim out the muscle that is in the palate, to make the palate thinner, then as you pull it forward you can shorten the palate and stitch it back.

  
• Arytenoid movement

  Inspiration - cartilages are abducted.

  Expiration - cartilages are abducted. (Air break)

  Expiration at exercise - cartilages are abducted.

  Size of the rima glottidis is determined by the respiratory needs of the animal.
• Aetiology of laryngeal paralysis

  Neurogenic atrophy f the intrinsic laryngeal muscles.

  Dysfunction of the recurrent laryngeal nerves.

  Generalised peripheral neuropathy involving long and large diameter nerve fibres.

  Central nervous system origin.
• Clinical signs of laryngeal paralysis

  Stridor

  Cough

  Dyspnoea

  Change in phonation (bark)

  Exercise intolerance

  Collapse

  Sings are related to the severity of the paralysis present

  Most dogs present late in the course of the disease.

  Clinical signs worse when the dog is hot excited and exercised.
• Diagnosis of laryngeal paralysis

  Characteristic clinical signs.

  Auscultation of the larynx and the thorax.

  Laryngoscope (under a light plane of general anaesthesia)

  Straight-bladed laryngoscope.
• Emergency medical management of laryngeal paralysis

  Rest (calm - both dog and owner)

  Supplemental oxygen

  Cooling

  Sedation

  Intravenous access

  Intravenous corticosteroids

  Anaesthetise => tracheostomy tube placement.
• Arytenoid lateralisation (tie back)

  Aims to widen the rime glottis and prevent dynamic collapse of the arytenoid cartilage.. Tie back one arytenoid cartilage (only one), if you tie both sides back in dog then the dog will almost certainly aspirate. Aspiration is most likely to occur in the first 24-48 hours and is most likely to be fatal if it occur post-operatively.
• Tracheal collapse

  More common in smaller dogs, generally refers to a condition of excessive collapsibilty of the trachea which usually results in Dorsoventral flattening of the tracheal lumen.
• Clinical signs of tracheal collapse

  Classic ‘goose honk’ cough. Pulling in collar and lead. Exercise. Anythogn that makes the dog cough.

  
• Medical management of tracheal collapse

  Antitussives (anti-cough medication).

  Bronchodilators.

  Antibiotics

  NSAIDs

  Corticosteroids (inhaled)

  Bronchodilators (inhaled).
• Surgical treatment of tracheal collapse

  If animal does not respond to medical management. Two options; Open ring prosthesis or stenting.

  Open ring prosthesis - where you do open surgery and stitch plastic rings to the trachea to keep it open.

  Stenting - more common, putting a wire cage into the tracheal lumen which is self-expanding to fill the tracheal lumen. After a period of time the stent will start to incorporate into the trachea.
• Fungal Rhinitis (Aspergillosis)


  Mainly seen in dogs (rarely in cats). Sinonasal aspergillosis. Common cause of nasal disease. Less common than neoplasia. Medium to long nosed breeds. A. fumigatus. Disease is generally restricted to nasal cavity and sinuses, but is markedly destructive to turbinates, can erode frontal bones and cribiform plate. Fungus eats away at the cartilage and bone, is painful and causes epistaxis, tends to present as unilateral disease but can be bilateral.
• Clinical signs of fungal rhinitis.

  Nasal discharge - Mucopurulent, unilateral - bilateral, intermittent epistaxis.

  Ulceration or depigmentation of the nasal planum.

  Sneezing,
• Diagnosis/ tests for fungal rhinitis


  History/ clinical signs. Blood tests - r/o coagulopathy, coagulation profile. Diagnostic imaging - radiography of nose and sinuses, CT/MRI. Rhinoscopy - rigid endoscope, flexible endoscope (anterograde sinuscopy). Cytology, Serology.
• Fungal rhinitis treatment

  Challenging to treat. Oral antifungal agents (Azoles). Requirtes prolonged treatment, side effects (anorexia, V+) common. Not recommended. Topical therapy - preferred option, enilconazole, clotrimazole. Delivered via catheter placement in frontal sinuses via surgery (~80% success - treat 7-14 days BID). there are minimally invasive methods but they have a worse long term prognosis.