Differential diagnosis
Inflammatory, allergic, infectious (e.g. bacterial, viral, fungal, or parasitic), heart disease, tracheal collapse, neoplasia (primary, metastatic), masses other than neoplastic, foreign body, overweight, trauma, degenerative or aging, noncardiogenic pulmonary edema, pleural effusion, open.
Diagnostics
Signalment, thorough history, physical exam findings (TPR, heart and lung auscultation, tracheal palpation, etc.), radiographs (especially thoracic views to help assess the heart, lungs, trachea and remainder of the thoracic cavity), blood work (cbc with pathology review, chemistry panel, heartworm antigen, coccidioidomycosis titer, proBNP, etc.), fecal (screening for causes such as lungworm infection), urine antigen (screening for causes such as blastomycosis and histoplasmosis), echocardiogram, respiratory panel PCR assay via nasal and nasopharyngeal swab, airway samples for cytology and culture via TTW and/or via bronchoscopy BAL, etc.
The respiratory tract contains normal microbiota which needs to be taken into consideration when interpreting test results, as well as taking into consideration any possible contaminants and opportunists. False negative and false positive test results are always possibilities – discuss this with owners when going over the patient’s treatment plan.
Treatments
Treat the cause (e.g. allergic, infectious, heart disease, tracheal collapse, neoplasia, etc.). Remember that it is possible for a patient to have concurrent diseases present.
Some infectious causes may not require treatment and may be self-limiting, such as acute upper respiratory tract infections. Remember the importance of practicing antimicrobial stewardship. It is typically recommended to not treat with antibiotics in the acutely coughing dog, but rather to monitor the patient for ~ 10 days to see if clinical signs resolve on their own. Treatment is based on the patient’s signalment, history, and the remainder of the diagnostic findings including the physical exam. Are there any additional clinical signs of a respiratory tract infection such as a productive cough, sneezing, mucopurulent nasal discharge, ocular discharge, conjunctivitis, crackles, wheezing, dyspnea, fever, lethargy, or inappetence? If clinical signs are significant, including progressing or having progressed to pneumonia, then even in the acutely coughing dog, initiating treatment with an antibiotic may be considered.
If a bacterial infection is suspected or confirmed, and if antibiotics are required, then unless diagnostics indicate a different antibiotic or dosage to be used, the empirical first-line antibiotic for respiratory tract infections in dogs is doxycycline at a dosage of 5 mg/kg PO q 12 hr for 7 to 10 days and then reassessing the patient. Doxycycline tablets and capsules can cause esophageal strictures (especially in small dogs or cats) – have owners administer with a soft treat and should follow administration with water or food to ensure passage of the tablet or capsule. In young patients, tetracycline risks include teeth discoloration and effects on bone formation – these risks are lower with doxycycline compared to other tetracyclines. Keep the patient separated from others to help prevent disease spread. Note that significant pneumonia +/- sepsis likely requires broader spectrum antibiotic combinations such as clindamycin/enrofloxacin.
Disclaimer: The information is intended to be used for educational purposes and as guidelines only. Medical recommendations and guidelines vary slightly among sources, and get updated and evolve periodically. Take into account a patient’s individual circumstances and don’t rely on this information alone. This information is not intended to replace clinical judgement or guide individual care in any matter. Please check any information and values prior to use and use at your own risk. Neither Vetpocket, the authors, nor any other party involved in the preparation, publication or distribution of any Vetpocket material shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any use of or reliance upon this information.
