14. Upper respiratory tract diseases: nose, nasal cavity, oropharynx, trachea

What are the two main types of breathing?

Costal (thoracic) and abdominal

What is normal breathing a combination of?

Costal and abdominal breathing (costo-abdominal)

What are some clinical signs of respiratory diseases?

Abnormal sounds, abnormal posture, abnormal mucous membranes, tachypnoea, weakness, and altered respiratory effort

What are the two main types of cough?

Dry: painful, irritation. Tx: antitussives

Wet: Tx: mucolytic, expectorants

What is cyanosis?

Insufficient oxygenation of the blood, haemoglobin problems, or stagnation of blood

What are the two main types of cyanosis?

Central: hypoventilation, airway obstruction, metHB

Peripheral: vessel obstruction, heart failure, shock

What is sneezing?

Nasal irritation; a deep inspiration followed by rapid expiration

What are some causes of acute/paroxysmal sneezing?

Viral infections, allergies, foreign bodies, trauma, and cold

What are some causes of chronic sneezing?

Neoplasia, parasites, and secondary infections

What is reverse sneezing?

A reflex of bringing air into the body to remove an irritant in the nose, characterised by backward head motion, closed mouth, and air being sucked in

What causes reverse sneezing?

Spasms of the throat triggered by an irritant

What are the different types of nasal discharge?

1. Serous (clear liquid): allergy, Kennel cough, foreign body in ear

2. Muco-purulent (thick, yellow-green): bacterial, fungal, parasitic, neoplasia,

3. Epistaxis (bleeding): trauma, rodenticides, neoplasia, oro-nasal fistula, dental problems,

4. Milk: palatoschisis- cleft palate

What is stertor?

Intermittent, yet persistent or continuous snorting

What is stridor?

Audible wheezing associated with restriction of airflow

What information should be gathered in the history for diagnosing respiratory diseases?

Signalment, environment, vaccination status, travel history, onset and duration of clinical signs, previous treatments, and response to therapy

What should be included in the clinical examination for diagnosing respiratory diseases?

Chest auscultation (at least four locations), percussion, assessment of respiratory depth and character, and palpation

Where should chest auscultation be performed?

At least four locations: cranial and caudal, dorsal and ventral, left and right

What does decreased percussion indicate?

Fluid or a mass

What does increased percussion indicate?

Air in the pleural space

What are normal lung sounds?

Vesicular or bronchial

What are some abnormal lung sounds?

1. Wheezes (small airway disease)

2. Crackles (fluid in lungs)

3. Bronchi (bronchial disease)

4. Dullness (consolidation)

5. Absence of sound (pleural disease)

What should be assessed during palpation?

Skin changes and symmetry

What is the normal respiratory rate for dogs?

10-30 breaths per minute

What is the normal respiratory rate for cats?

20-40 breaths per minute

What is induction of cough used for in respiratory examinations?

To assess the nature and productivity of the cough, irritability of respiratory tract

What laboratory examinations can be used to diagnose respiratory diseases?

Blood gas analysis, cytology, pulse oximetry, capnography, nasal biopsy, nasal cultures, and latex agglutination tests

What imaging methods can be used to diagnose respiratory diseases?

Radiography, CT, and endoscopy (rhinoscopy)

What are some common nasal disorders?

Neoplasia, infection, foreign bodies, fractures, and fungal infections

What are some historical findings associated with nasal disorders?

Nasal discharge (unilateral/bilateral, serous/purulent/haemorrhagic), paroxysmal sneezing, and gagging

What are some common findings associated with nasal disorders on examination?

Mucosal oedema, inflammation, and secondary bacterial infections

What is rhinitis?

Inflammation of the mucous membranes of the nose

What are some causes of rhinitis?

1. Infectious

   1. Viral (Kennel cough, Calicivirus, herpesvirus)

   2. Bacterial (Bordetella, chlamydia, mycoplasma),

   3. Fungal (cryptococcus, aspergillosis)

   4. Parasites – Mite: Pneumonyssoides caninum)

2. Allergy

3. Tooth root abscess

4. Oronasal fistula (cleft palate)

5. Deformed turbinates

6. Nasal tumours (polyps)

7. Foreign material (grass seeds/straw)

What are some clinical signs of rhinitis?

Nasal discharge (unilateral or bilateral, serous/purulent/haemorrhagic), sneezing, reverse sneezing, gagging, coughing (dry or wet), lethargy, and oral ulcers

How is rhinitis diagnosed?

Based on the cause, visualisation by rhinoscope, FNA of tumours, nasal swabs, nasal flush, and X-rays or nasal endoscopy

What are some treatments for rhinitis?

Aggressive flushing, treatment according to the cause (antibiotics, NSAIDs, surgery to remove obstructions, forceps to remove foreign objects)

What are the most common pharyngeal disorders in dogs?

Brachycephalic obstructive airway syndrome (BOAS) and soft palate disorders

What are the most common pharyngeal disorders in cats?

Nasopharyngeal polyps and neoplasia

What are some other pharyngeal disorders?

Foreign bodies, abscesses, granulomas, extraluminal masses, and nasopharyngeal stenosis

How are pharyngeal diseases diagnosed?

Endoscopy, X-ray, ultrasound, fluoroscopy, CT, and MRI

What are examples of diseases of the larynx?

1. Laryngeal paralysis

2. Laryngeal collapse

3. Obstructive laryngitis

4. Laryngeal neoplasia (rare, more common with adjacent tumours like thyroid carcinoma)

What is laryngeal paralysis?

Loss of normal function of the larynx due to paralysis of the muscles controlling the arytenoid cartilages and vocal cords during inspiration

Which dogs are predisposed to primary laryngeal paralysis?

Older large and giant breeds

What are some causes of laryngeal paralysis?

Congenital conditions, hypothyroidism, neuropathies, neoplasia, and mostly idiopathic causes

What are some clinical signs of laryngeal paralysis?

Dry cough, voice change, stridor, choking, gagging, dyspnoea, cyanosis, wheezing on laryngeal auscultation, and dysphagia

How is laryngeal paralysis diagnosed?

Laryngoscopy (asymmetry between the arytenoids and vocal cords)

What are some treatments for laryngeal paralysis?

1. Surgery (laryngoplasty)

2. Medical management (prednisone)

3. Conservative management (avoiding exercise)

What is laryngeal collapse?

Weakening of the laryngeal cartilages due to chronic negative pressure from increased inspiratory effort

What is the most common cause of laryngeal collapse?

Chronic airway obstruction related to brachycephalic syndrome

What are some clinical signs of laryngeal collapse?

Noisy breathing, snorting, dyspnoea, cyanosis, gagging, choking, vomiting, and restlessness

What is the treatment for laryngeal collapse?

Surgical correction of the underlying cause

What are examples of tracheal diseases?

1. Tracheal collapse

2. Tracheobronchitis

3. Foreign body

4. Tracheal rupture

5. Tracheal tumour

Which species is tracheal collapse more common in?

Dogs (possible but rare in cats, usually trauma-induced)

Which dog breeds are predisposed to tracheal collapse?

Miniature breeds (Yorkshire Terrier, Chihuahua)

What is the typical age of onset for tracheal collapse?

Middle-aged to older

What are some risk factors for tracheal collapse?

Obesity

What causes tracheal collapse?

1. Weakening of tracheal rings or the dorsal ligament

2. Weakening and stretching of the trachea muscle

3. Can be congenital, due to obesity, nutritional factors, bacterial infection, neurological issues, chronic airway disease, or idiopathic

What are the grades of tracheal collapse?

1-4

What are some clinical signs of tracheal collapse?

Chronic dyspnoea, harsh "goose honking" cough, proneness to heat stroke, cyanosis, syncope, respiratory distress, exercise intolerance, wheezing, fainting, and worsening of signs with increased temperature or excitement

How is tracheal collapse diagnosed?

Clinical signs, history, tracheal palpation, endoscopy, bloodwork (polycythaemia, hypoxia, leukocytosis), and radiographic examination (inspiratory vs. expiratory films)

What are some treatments for tracheal collapse?

1. Cough suppression (butorphanol or codeine),

2. Bronchodilators

3. Weight loss

4. Surgical correction (tracheal prosthetic rings)

5. Antibiotics (to reduce complications)

What must be considered before administration of butorphanol/cough suppression?

The heart of the patient must be able to handle it

What is tracheobronchitis?

Inflammation of the trachea and bronchial tree

What are some causes of tracheobronchitis?

Viral and bacterial infections

What are some predisposing factors for tracheobronchitis?

Kennel/shelter environments, poor nutrition, dry mucous membranes, and anaesthesia

What are some clinical signs of tracheobronchitis?

Sudden, dry, harsh cough, fever, sneezing, nasal discharge, whistling noise, and conjunctivitis

How is tracheobronchitis diagnosed?

Full clinical exam, history, haematology, biochemistry, serology, and cytology

What are some treatments for tracheobronchitis?

Antitussives (butorphanol), antibiotics, and corticosteroids

What is eupnea?

Normal quiet respiration

What is dyspnoea?

Difficult/laboured breathing

What is apnoea?

Absence of breathing

What is hyperpnea?

Increased depth of breathing

What is panting?

Increased rate of breathing (ventilation) as a mechanism to dissipate heat, with little change in gaseous exchange

What is polypnea?

Rapid shallow breathing

What is anoxia/hypoxia?

Absence or deficiency of oxygen in the tissues

What is orthopnea?

Increased respiratory distress when the patient is lying down or the chest is compressed

What is hyperventilation?

Ventilation that exceeds metabolic demands, resulting in hypocapnia (reduced PaCO2)

What is hypoventilation?

Ventilation that does not meet metabolic demands, resulting in hypercapnia (increased PaCO2)

What is stertor?

Heavy snoring sound

What is stridor?

Harsh, high-pitched sound during inhalation or exhalation

How is a wet cough treated?

Mucolytics

What is the most likely cause of sudden onset of sneezing?

Grass seeds or foreign bodies

With which type of nasal discharge should ATB be used?

Mucopurulent

How can problems in the nasal cavity be visualised?

Rhinoscopy, caudal rhinoscopy, x-ray, CT, MRI

What is epistaxis, and what are differential diagnoses for uni/bilateral epistaxis?

• Epistaxis: bleeding from one or both nostrils

• DDx: trauma, clotting disorders, foreign body, neoplasia