The duration of a dog's respiratory infection depends on various factors, such as the type of infection, the severity of the infection, the dog's overall health, and how quickly treatment is initiated. Generally, a mild respiratory infection, such as an upper respiratory infection, may last from 7 to 14 days, while more severe infections, such as pneumonia, may take several weeks to resolve completely. Prompt and appropriate treatment is crucial to help speed up recovery and prevent complications. In the case of bacterial infections, a veterinarian will prescribe antibiotics, and it's essential to complete the full course as directed. Viral infections may require supportive care, such as hydration, rest, and proper nutrition, while the dog's immune system fights off the virus. If a fungus or parasite causes the infection, specific medications will be prescribed to address the issue. Monitoring your dog closely during their recovery and following your veterinarian's recommendations is essential. If your dog's condition worsens or does not improve within the expected timeframe, contact your veterinarian for further evaluation and advice.