Dog Flu Diagnosis: Identifying Canine Influenza
Jun 30
Dog Flu should be suspected in dogs with respiratory signs.
Because of the increasing prevalence of Dog Flu (canine influenza), the rapid spread of the infection among dogs, and the potential for up to 20% of dogs to have a severe disease course, veterinarians and other pet care professionals should examine further any dogs with cough, nasal discharge or fever. Dog Flu infection should be suspected in dogs with persistent cough and those with pneumonia or other clinical signs of more severe respiratory illness. It is important for diagnostic tests to be performed to determine the cause of canine cough outbreaks because Dog Flu symptoms can sometimes seem like other respiratory infections. A clinic can use multiple methods to test for both strains (CIV H3N8 and CIV H3N2). Each of these tests can help with different readings. Several methods may be used on one dog because results can vary depending on the stage of infection of Dog Flu in the dog. A veterinarian should be contacted for guidance on appropriate testing, as well as isolation precautions and treatment.6 Remember that a positive test for other respiratory infections does not rule out Dog Flu, since secondary infections are common.Summary of Diagnostic Testing Options for Dog Flu:
| Diagnostic test | Description |
|---|---|
| Flu Antigen ELISA | BD Directigen™ Flu A Test Kit, Quidel Quickvue® What: Human influenza A test that can be used for Dog Flu How: Obtain nasal and/or pharyngeal swabs from dogs within 4 days of clinical signs onset Results: False negatives uncommon |
| Serology | How: Obtain samples one week after onset of signs, and a second sample 2-3 weeks later Results: Can indicate a recent infection or past exposure in a dog without canine vaccinations |
| PCR | IDEXX real-time PCR panels How: Most sensitive before onset of signs in recently exposed dogs Results: False negatives common after onset of signs |
| Virus Isolation | How: Collect nasal swabs as early as possible, before antibodies develop, in order to track genetic changes in virus as it spreads through the dog population Results: Relatively unreliable way to confirm infection due to timing of sample collection |
