Page 311 - Small Animal Internal Medicine, 6th Edition

CHAPTER 19 Clinical Manifestations of Lower Respiratory Tract Disorders 283

BOX 19.1 BOX 19.2
VetBooks.ir Differential Diagnoses for Lower Respiratory Tract Differential Diagnoses for Productive Cough* in Dogs
and Cats
Disease in Dogs and Cats
Disorders of the Trachea and Bronchi Edema
Canine infectious respiratory disease complex Heart failure
Canine chronic bronchitis Noncardiogenic pulmonary edema
Tracheobronchomalacia (collapsing trachea and/or
bronchi) Mucus or Exudate
Feline bronchitis (idiopathic) Canine infectious respiratory disease complex
Allergic bronchitis Canine chronic bronchitis
Bacterial, including Mycoplasma, infections Feline bronchitis (idiopathic) †
Oslerus osleri infection Allergic bronchitis †
Neoplasia Bacterial infection (bronchitis or pneumonia)
Foreign body Parasitic disease †
Tracheal tear Aspiration pneumonia
Bronchial compression Fungal pneumonia (severe)
Left atrial enlargement
Hilar lymphadenopathy Blood (Hemoptysis)
Neoplasia Heartworm disease †
Neoplasia
Disorders of the Pulmonary Parenchyma and Vasculature Fungal pneumonia
Infectious diseases Thromboembolism
Viral pneumonias Severe heart failure
• Canine influenza Foreign body
• Canine distemper Lung lobe torsion
• Calicivirus Systemic bleeding disorder
• Feline infectious peritonitis
Bacterial pneumonia *Because it can be difficult to determine the productive nature of a
Protozoal pneumonia cough in veterinary medicine, these differential diagnoses should
• Toxoplasmosis also be considered in patients with nonproductive cough.
Fungal pneumonia † Diseases of the lower respiratory tract most often associated with
• Blastomycosis cough in cats. Cough in cats is rarely identified as productive.
• Histoplasmosis
• Coccidioidomycosis
Parasitic disease
• Heartworm disease EXERCISE INTOLERANCE AND
• Pulmonary parasites RESPIRATORY DISTRESS
• Paragonimus infection Diseases of the lower respiratory tract can compromise the
• Aelurostrongylus infection
• Capillaria infection lung’s function of oxygenating the blood through a variety
• Crenosoma infection of mechanisms (see the section on blood gas analysis in
Aspiration pneumonia Chapter 20). Clinical signs of such compromise begin as
Eosinophilic lung disease mildly increased respirations and subtly decreased activity
Idiopathic interstitial pneumonias and progress through exercise intolerance (manifested as
Idiopathic pulmonary fibrosis reluctance to exercise or respiratory distress with exertion)
Pulmonary neoplasia to overt respiratory distress at rest. Because of compensa-
Pulmonary contusions tory mechanisms, the ability of most pets to self-regulate
Pulmonary hypertension their activity, and the inability of pets to communicate,
Pulmonary thromboembolism many veterinary patients with compromised lung function
Pulmonary edema arrive in overt respiratory distress. Dogs in overt distress will
often stand with their neck extended and elbows abducted.
Movements of the abdominal muscles may be exagger-
by the times of day during which they have the most contact ated. Healthy cats have minimally visible respiratory efforts.
with their pets, often in the evenings and during exercise. Cats that show noticeable chest excursions or open-mouth
It is surprising to note that cats with many of the disorders breathing are severely compromised. Patients in overt dis-
listed in Box 19.2 do not cough. In cats that cough, the index tress require rapid physical assessment and immediate sta-
of suspicion for bronchitis, lung parasites, and heartworm bilization before further diagnostic testing, as discussed in
disease is high. Chapter 25.