Second, the presence of a cough that can be induced with tracheal pressure does not indicate that the problem is tracheal
or bronchial. Dogs with pulmonary parenchymal abnormalities, such as cardiogenic pulmonary edema, or even normal dogs, will
cough with tracheal pressure.
Since a cough indicates an underlying respiratory problem, it is important to determine the nature of the problem before deciding
With a purposeful cough, the treatment goal is to help eliminate the unwanted material from the respiratory system. Treatments
to consider include antibacterials, nebulization and coupage (if bacterial pneumonia), medical management of the underlying
cause if present (e.g., megaesophagus) and lung lobectomy if indicated (e.g., foreign body).
Additional diagnostic tests that may help establish the need for specific treatments include transtracheal wash, bronchoscopic
examination and bronchoalveolar lavage and computed tomography (CT) or magnetic resonance imaging (MRI) of the thorax. A treatment
that is contraindicated is the use of cough suppressants.
With a warning cough, treatment goals are to address the underlying problem before further deterioration and to provide emergent
supportive care. Treatments to consider include oxygen supplementation for dyspneic dogs; diuretics in cases of cardiogenic
pulmonary edema; crystalloid fluid therapy, plasma transfusion and vitamin K in cases of pulmonary hemorrhage due to anticoagulant
rodenticide intoxication; anticoagulants (and possibly plasma transfusions or other therapies based on inciting factor) in
cases of PTE; chemotherapy, radiation therapy, and/or surgical therapy for neoplasia; and surgical correction in cases of
Additional diagnostic tests that may help establish the need for specific treatments may include an echocardiogram and electrocardiogram
(if cardiogenic pulmonary edema), prothrombin time (if anticoagulant rodenticide toxicity), platelet count, fibrin degradation
products measurement, d-dimer assay, assessment of antithrombin III levels and possibly a lung perfusion scan or pulmonary
arterial angiogram (if PTE is suspected) and thoracic ultrasound, CT, and/or MRI and needle aspiration or biopsy of thoracic
masses. Contraindicated treatments include cough suppressants and expectorants.
With a nuisance cough, the dominant goal of treatment is comfort. Treatments to consider include cough suppressants (except
if a secondary bacterial infection or ventilation problem is present), environmental modification (e.g., air purifier, avoidance
of exposure to airborne infectious agents), weight loss if the dog is obese, bronchodilator drugs, and tranquilizers used
on an as-needed basis if anxiety appears to play a role in triggering or sustaining the cough.
Additional diagnostic tests that may help establish the need for specific treatments may include transtracheal wash, bronchoscopic
examination and bronchoalveolar lavage. A treatment that is contraindicated is the use of expectorants.
Prognosis and outcome
With a purposeful cough, the outcome depends on the ability to eliminate the source. Extraction of a foreign body generally
carries a good prognosis, for example, whereas bacterial pneumonia caused by chronic aspiration associated with megaesophagus
carries a guarded prognosis due to the high likelihood of recurrence.
More frustrating in terms of exact prognosis is the juvenile dog with pneumonia secondary to suspected viral or primary bacterial
causes (e.g., canine distemper, Bordetella, etc.). These young dogs may clear the infection but have persistent regional compromises
of local immune function, fostering variable degrees of reinfection. In such cases, the cough may move from purposeful, when
pneumonia is present, to nuisance, when pneumonia is absent, and back again, for months or years.
The prognosis associated with a warning cough is directly related to two factors: (1) the speed with which the animal is brought
for evaluation and the underlying problem is correctly diagnosed; and (2) the response to treatment for the underlying problem.
For instance, a dog with pulmonary hemorrhage from severe anticoagulant poisoning can have an excellent outcome if treated
early and appropriately; the same dog may die if not evaluated and treated rapidly.
Nuisance coughs carry a fair prognosis. When caused by severe, worsening compromise of the airways (e.g., advanced cases
of collapsing trachea or bronchial compression from cardiac enlargement), the prognosis is guarded. However, when nuisance
coughs are not caused by such disorders, they can be treated on an as-needed basis and are compatible with a good quality
Johnny D. Hoskins
Dr. Hoskins is owner of DocuTech Services. He is a diplomate of the American College of Veterinary Internal Medicine with
specialities in small animal pediatrics. He can be reached at (225) 955-3252, fax: (214) 242-2200 or e-mail: