Page 107 - Problem-Based Feline Medicine

7 – THE COUGHING CAT 99

instruments to be utilized than with a flexible Fires may cause thermal damage to the upper airway.
endoscopy. Burning plastics release toxic fumes causing direct
chemical damage to lungs.
Bronchial foreign bodies may cause complete lobar
atelectasis or abscessation radiographically. The right Carbon monoxide exposure results in carboxyhemoglo-
caudal and accessory lobes are most often affected with bin formation, lowering the oxygen-carrying capacity
inhalation foreign bodies. The right middle lobe is of hemoglobin, and worsening the hypoxemia.
affected commonly with aspiration of vomitus.
Airways irritated by underlying disease such as bron-
chitis, may be hyperresponsive to cigarette smoke or
Differential diagnosis household fumes.
Nasopharyngeal polyps may cause similar signs of
nasal obstruction and sneezing, but tend to have a more
chronic course. Clinical signs
Tracheal or bronchial neoplasia may have similar Patients rescued from fires smell of smoke, have burned
signs, but again are more chronic in nature and can be hair or vibrissae, may be coughing, and are often
distinguished bronchoscopically. expectorating soot-tinged sputum.
Cherry-red mucus membranes indicate carboxyhe-
Treatment moglobinemia, and cyanosis indicates hypoxemia.
Removal of the foreign body, either surgically or endo- Stridor and inspiratory dyspnea suggest laryngeal
scopically, is often curative. Nasal foreign bodies may edema.
be endoscopically retrieved or hydropulsed, but occa-
Crackles indicate increased airway fluid.
sionally require surgical rhinotomy.
Wheezes indicate diminished airway diameter via
Bronchial foreign bodies, especially with lung lobe
bronchoconstriction, congestion, mucus accumulation,
abscesses, require lung lobectomy.
and airway edema.
Prognosis
Excellent with removal of the foreign body. Diagnosis

Presumptive diagnosis is based upon evidence of recent
Prevention
exposure to noxious agent and acute onset of coughing.
Hairball prophylaxis.
Thoracic radiography.
Avoidance of grass fields during seed time. ● May vary from peribronchiolar to patchy interstitial
lung pattern, with possible lobar consolidation.
● Infiltrates are generalized, although the caudodorsal
INHALATION OF NOXIOUS AGENTS
fields may be more affected.
● These changes may lag several hours behind clinical
Classical signs
signs.
● Acute onset of severe coughing.
Pulse oximetry may indirectly assess oxygenation
● Evidence of inhalation of gas, smoke,
through SPO (hemoglobulin saturation).
fumes, dust particles or hair. 2
Blood gases.
● Arterial oxygen (PaO ) represents dissolved oxy-
Pathogenesis 2
gen content not bound to hemoglobin.
Poor ventilation, engine exhaust, smoke from fires or ● PaO < 60 mmHg indicates severe hypoxemia,
2
cigarettes, all can stimulate an aggressive cough reaction. ofetn associated with cyanosis.