Canine Influenza: an emerging disease on the rise
Canine Influenza is a systemic viral infection which primarily causes upper respiratory symptoms similar to “kennel cough”, but can be much more serious. 10% of infected dogs can go on to develop a potentially life-threatening pneumonia. There are several factors that make this disease even more serious.
1) Because the disease is new (one strain is about 8 years old and the other 2 years old), dogs do not harbor antibodies obtained from their mothers or from environmental exposure. This makes them higher risk to get sick.
2) The virus can be shed before illness occurs and potentially for weeks after recovery. This means a dog without any symptoms can infect other dogs.
3) Because dogs travel with their owners, the virus is not staying localized but spreading in a manner like human influenza.
About the Virus
There are two strains. The first stain is called H3N8 and originates from an equine influenza virus which spread to racing greyhounds in Florida in 2004 (it is suspected they were fed raw rendered horse-meat). These dogs were adopted out and exposed the general dog population. The second strain is called H3N2 and is from a bird influenza that came from Korea. The first outbreak came in Chicago in 2015 and the city was hit very hard with massive infections. It has since spread.
How It Spreads
The Influenza virus spreads via secretions from: direct contact, contaminated surfaces, and the humans who care for the dogs. Surfaces can be contaminated for up to 48 hours after contact, clothing 24 hours, and hands for 12 hours. The more crowded the conditions, the more likely infection. This means that pet stores, shelters, kennels, grooming shops, doggie day care, dog-walkers, and dog parks pose the highest risk. 80% of infected dogs will show symptoms ranging from mild cough and sneezing to fever, severe coughing, anorexia, lethargy, and death. Infected dogs with no obvious symptoms can still shed the virus and are contagious. H3N2 has been found to be shed up to 26 days after infection.
Transmission of H3N2 (new strain) has been documented from dog to cat and then from cat to cat. There have been no reported cat fatalities. While no human transmission has been documented, because this was originally an avian flu, there is cause for concern and prevention is crucial.
Diagnosis
Diagnosis of influenza can be challenging, as initial symptoms look like typical kennel cough. Special testing is required. This can be via a swab of the eyes, nose, or throat looking for viral particles. This test must be performed within a few days of infection and if too few particles are found, then an infected dog can test negative. A special blood test looking for antibodies can be performed, checking blood tests a week apart. It takes a few more days to get the results which mean it can be several weeks between initial symptoms and getting an answer.
Treatment
There is no specific treatment for influenza in dogs. We can only treat symptomatically. If a secondary bacterial infection is found, then we can use antibiotics for that. But antibiotics don’t help viruses.
Prevention
The best option is vaccination. There is now a vaccine which contains both strains of Influenza. The vaccine isn’t 100% but will reduce the severity of symptoms and duration of the illness (hopefully to none at all). The initial vaccination is a series of two injections, given over the right shoulder, about 3 weeks apart and then annually thereafter.
We recommend vaccination for any dog which will be considered at higher risk: boarding, grooming, dog parks, etc. Basically a good rule is: if a pet owner or dog will be exposed to secretions from another dog, their own dogs should be vaccinated for influenza.
Vaccination will be mandatory for our dog patients who go to doggie day care, grooming, or boarding. It is for the protection of all of our canine and feline patients. A complete physical exam within the last 12 months is required before vaccination.
There is no vaccination for cats.
Because we cannot differentiate between typical kennel cough and the flu, all symptomatic dogs need to be kept isolated from other dogs for 21 days from the onset of symptoms.
In Order to protect your dog and other dogs in our care, we are requiring Influenza Vaccination for all Dogs staying here for Boarding and Grooming. Vaccination is a series of two injections about 3-4 weeks apart, followed by annual re-vaccination.
If you have any questions, please let an OCVMC team member know.