Update – Canine Influenza Outbreak In Las Vegas 

Las Vegas Specific Information

Recently, there have been reports of confirmed cases of canine influenza (CI) from reputable Las Vegas shelters and animal organizations such as the Animal Foundation, Henderson Animal Shelter, and Nevada SPCA. While Pet Health Hospital has not identified any confirmed cases of CI, pet parents must be vigilant and well-informed about this contagious respiratory illness. We are updating our previous CI vaccine recommendations to allow our pet parents to best safeguard their pets against CI and other potential health threats.

Summary of Canine Influenza

Canine influenza, also known as dog flu, is a highly contagious viral respiratory infection caused by two strains of the influenza A virus: H3N8 and H3N2. The H3N8 strain was first recognized in racing greyhounds in Florida in 2003, while the H3N2 strain emerged in dogs in Asia in 2007 before spreading to the United States in 2015. Both strains of CI cause respiratory illness in dogs, with symptoms ranging from mild to severe.

CI outbreaks are often associated with high-density dog populations, such as boarding facilities, shelters, and dog parks, where close contact between dogs facilitates viral transmission. Dogs infected with CI can be contagious to other dogs for up to seven days after exposure, leading to outbreaks in congregate settings.

Clinical signs of CI include coughing, sneezing, nasal discharge, fever, lethargy, and reduced appetite. While most cases of CI cause mild respiratory illness, some dogs may develop severe pneumonia. In rare instances, CI can be fatal, with mortality rates typically less than 1-2%.

Diagnosing CI involves PCR testing of respiratory specimens to detect the presence of the influenza virus. Additional diagnostic tests, including bloodwork and chest radiographs (X-rays), may be performed to assess the severity of respiratory disease and rule out other underlying conditions.

Treatment for CI is primarily supportive and focused on managing clinical signs and preventing complications. Rest, hydration, and symptomatic relief may be sufficient in mild cases, while more severe cases may require hospitalization, intravenous fluids, oxygen therapy, and antibiotics to address secondary bacterial pneumonia.

Preventing CI is critical to minimizing its spread and impact on canine health. Vaccination is available for both H3N8 and H3N2 strains of CI. The CI vaccine does not provide complete immunity but can reduce the severity and duration of illness and viral shedding in vaccinated dogs.

Information About the Canine Influenza Vaccination

The vaccination protocol typically consists of two doses administered two to four weeks apart, followed by annual booster vaccinations to maintain protective immunity. Overall, the vaccine is considered safe, with few adverse reactions reported. Some dogs have underlying health conditions for which vaccines pose an increased risk; your Pet Health veterinarian will discuss these conditions before deciding to vaccinate for CI.

Historically, Pet Health veterinarians have not recommended canine influenza vaccination except when a daycare or boarding facility requires the vaccine. However, in the face of the increased risk in our community, we now recommend the vaccine for any dog exposed to other dogs with unknown health status. If the incidence of influenza in the community changes, we will update our recommendations accordingly. Our goal is constantly adapting to the changing health environment to give your pets the best care.