Co-infections with Respiratory Viruses in Dogs with Bacterial Pneumonia

Viitanen, S.J.; Lappalainen, A.; Rajamäki, M.M.

In the PCR analysis of BALF or TTW fluid, CPIV was detected in 7/20 (35%; 95% confidence interval, 14-56%) and CRCoV in 1/20 (5%; 95% confidence interval, 0-15%) dogs with BP. CAV-2, CHV, CIV, CDV, or CnPnV were not detected in any of the samples. Dogs with positive virus PCR did not have other diseases predisposing to BP. Respiratory viruses were not detected in dogs with BBTB. 47 Intracellular bacteria were seen in 6/11 dogs with significant bacterial growth in primary culture. In 1 dog with a negative primary culture and prior antimicrobial treatment, >2 intracellular bacteria/oil immersion field were demonstrated, and Actinomyces sp. was cultured after enrichment. 47 A negative bacterial culture in airway samples was recorded in 4/20 dogs (2 had received prior antimicrobial treatment), but they showed an acute onset of respiratory signs and had new alveolar densities in thoracic radiographs as well as neutrophilia in BALF cytology. All of these dogs showed a rapid response to antibiotics, and a full clinical and radiographic cure was Information on previous CDV, CAV-2, and CPIV vaccinations was available for all dogs with BP. All dogs with positive CPIV PCR in respiratory samples (n = 7) had been vaccinated against CPIV <12 months previously (median, 6.5 months; interquartile range, 4.5-9.0 months). In total, 12/13 dogs with negative CPIV PCR in respiratory samples were vaccinated against CPIV (median, 13.0 months; interquartile range 2.9-24 months). There was no significant difference in the timing of CPIV vaccination between dogs with positive and negative respiratory virus PCR (P = .152). All dogs participating in this study had previously been vaccinated against CAV and CDV.