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| Bordetella BronchiSeptica & CanIne Influenza VIRus (H3n8) Today's Veterinary Practice July/August 2014 32 tvpjournal.com Shedding & Survival Most viruses begin shedding within 2 days post infection, and may continue to shed for 6 to 10 days before viral load decreases. 5 B bronchiseptica can survive in the envi- ronment for extended periods of time, 1 and can be shed from dogs that appear healthy because it has the ability to elude the immune system for weeks to months. INITIAL DIAGNOSIS Although definitive diagnosis is pursued in some cases, a suspected clinical diagnosis can often be made based on: • Clinical signs • Assessment of risk/exposure • Response to appropriate treatment. Clinical Presentation Clinical presentation varies among individual cases of B bronchiseptica and CIV infections, based on severity and concurrent bacterial and/or viral pathogens involved. Clinical signs include: • Acute onset of a nonproductive cough (most common clinical sign) • Serous or mucopurulent nasal and/or ocu- lar discharge • Sneezing • Tachypnea, respiratory distress, systemic ill- ness, and fever (more severe cases). Thoracic Radiographs Thoracic radiographs may support a diagno- sis of B bronchiseptica or CIV (Table 2) but, more important, help to rule out other causes of acute cough. Thoracic radiographs are recommended for any patient with: • Persistent (> 1–2 weeks) or worsening cough • Respiratory distress • Signs of systemic illness (eg, lethargy, decreased appe- tite). In more severe cases, radiographs are necessary to evalu- ate if pneumonia is present. Thoracic radiographs are not typically indicated in oth- erwise healthy patients with acute onset of only cough- ing (no signs of respiratory distress, tachypnea, fever, or systemic illness). Laboratory Analysis In complicated cases, a complete blood count and serum biochemical profile should be performed to assess sys- temic health, but these diagnostics are not generally nec- essary for diagnosis of B bronchiseptica or CIV. Table 2. B bronchiseptica & CIV Infections: Radiographic appearance TYPE OF INFECTION RADIOGRAPHIC APPEARANCE Uncomplicated B bronchiseptica or CIV (confined to upper respiratory tract) • normal thoracic radiographs • Diffuse bronchial or bronchointerstitial lung pattern • narrow tracheal lumen, creating a hypoplastic appearance due to tracheal mucosal edema Complicated B bronchiseptica or CIV (lower respiratory tract involvement) • Heavy interstitial, bronchial, or alveolar lung pattern (Figure 2) • With B bronchiseptica, focal alveolar pattern consistent with pneumonia • With CIV, diffuse or patchy interstitial or alveolar lung pattern consistent with pneumonia Figure 2. Radiographs from a 7-month-old basset hound puppy with Bordetella bronchiseptica pneumonia; note the diffuse heavy interstitial to alveolar lung pattern, which is most severe on the left side.