Canine influenza virus (CIV) is a type of influenza A virus that infects dogs and causes respiratory illness. There are two strains of CIV: H3N8 and H3N2¹. Both strains can cause mild to severe symptoms, such as coughing, sneezing, nasal discharge, fever, lethargy, and loss of appetite². In rare cases, CIV can lead to complications such as pneumonia, dehydration, or secondary bacterial infections³.
The mortality rate of CIV is low, ranging from 1% to 8%⁴. Most dogs recover from CIV within two to three weeks with supportive care, such as fluids, antibiotics, and anti-inflammatory drugs⁵. However, some dogs may have chronic respiratory problems or develop fatal conditions such as hemorrhagic pneumonia. Dogs that are very young, old, or have underlying health issues are more likely to have severe or fatal outcomes from CIV.
CIV is highly contagious and can spread through direct contact, airborne droplets, or contaminated objects². Dogs that are exposed to crowded or stressful environments, such as kennels, shelters, grooming parlors, or dog parks, are at higher risk of contracting CIV. There is no specific treatment for CIV, but there are vaccines available that can reduce the severity and duration of symptoms, as well as the risk of transmission. The vaccines are not 100% effective, and they do not protect against both strains of CIV, so vaccinated dogs can still get infected.
The best way to prevent CIV is to avoid contact with sick or unknown dogs, and to isolate any dog that shows signs of respiratory illness. Dog owners should also consult their veterinarians about the benefits and risks of vaccinating their dogs against CIV, especially if they live in areas where CIV outbreaks have occurred or if they plan to travel with their dogs. CIV is not known to infect humans, but it can infect other animals, such as cats, ferrets, and guinea pigs. Therefore, dog owners should also keep their dogs away from other pets that may be susceptible to CIV.
(1) Key Facts about Canine Influenza (Dog Flu) – CDC. https://www.cdc.gov/flu/other/canine-flu/keyfacts.html.
(2) Dog Flu: Symptoms, Treatment, and Prevention for Canine Influenza. https://www.akc.org/expert-advice/health/dog-flu-canine-influenza/.
(3) Canine influenza – Wikipedia. https://en.wikipedia.org/wiki/Canine_influenza.
(4) Canine Flu: Highly Contagious – American Kennel Club. https://www.akc.org/expert-advice/health/canine-flu-highly-contagious/.
(5) Canine Influenza Virus | Merck Animal Health USA. https://www.merck-animal-health-usa.com/nobivac/canine-influenza-virus.