PSA: Canine Influenza H3N2 Outbreak

PSA: Canine Influenza H3N2 Outbreak

If you are a dog owner, then you need to understand the ramifications of the H3N2 canine influenza virus. Originally, H3N2 was an influenza virus that affected birds, leading to the name avian influenza. However, this virus has mutated, and it now can affect canines, including domesticated dogs. This disease is common in certain regions of the United States because an infected dog can transmit the condition to another dog. The places where numerous dogs congregate such as parks, kennels or dog shows are where an animal is most likely to become infected. During the late 1990s through 2003, a large number of racing dogs were infected with this influenza, and many died due to respiratory distress. For humans, getting the flu vaccine and seeking a doctor’s advice is the best way to prevent influenza from taking hold. But what about your dog? Is your furry friend susceptible, and how can you keep him safe?

What Is Canine Influenza?

Canine Influenza (sometimes referred to as the “dog flu”) is an illness usually caused by the virus H3N8. The H3N8 virus first originated in horses over 40 years ago, and remains in equine populations today at a reduced rate. It is also sometimes caused by the H3N2 virus, a germ that originated in pig populations in the United States. Researchers believe that there is a possible connection between the H3N8 and H3N2 viruses and other human and animal influenzas (specifically Type A influenzas). This includes the famous H1N1 virus. Understanding how these viruses are related starts with understanding how viruses spread. Influenza viruses largely spread by mutation. That’s why the human influenza vaccine changes each year to keep up with new variations. These variations can also sometimes change the nature of the flu, allowing or disallowing it to attack a certain species. This is called zoonoses, and it explains how both the H3N8 and H2N2 viruses originally transferred from horses and pigs to dogs in the first place. While there is always a risk for a virus to mutate and become harmful to humans, there is absolutely no evidence to support the fact that H3N8 and H3N2 are zoonotic between humans and dogs. Confusion about the Canine Influenza Type A virus H3N2 and its cousin, H3N2v, often leads people to believe that humans can be infected by it. But H3N2v is a variant of the H3N2 virus, and isn’t the same. H3N2v can infection humans, but cannot infect dogs.

Risk Factors

Because Canine Influenza is a communicable disease, certain canine populations may have an increased risk of transmission. This includes dogs living in multi-dog homes, dogs living in shelters, dogs living on farms, and stray or otherwise homeless dogs. Canine Influenza can also spread through wild dog (i.e. wolf or coyote) populations, though there isn’t any evidence of transmission from wild dogs to pet dogs. Certain dogs may have a higher risk for both transmission and complications due to their current health state. This includes dogs with:
  • Diabetes
  • Heart conditions
  • Respiratory conditions
  • Auto-immune diseases
  • Lowered immune systems
  • Certain genetic deformities
  • Other chronic illnesses
Dogs who are on chemotherapy or immunosuppressant drugs (i.e. steroids) also have an increased risk to contract the illness, as do very young dogs who may not yet have a fully developed immune system.  

Symptoms of Canine Influenza

Over 20 states have confirmed reports of canine influenza cases with Colorado, Florida and New York reporting the most infected dogs. Only about 80 percent of dogs infected with canine influenza develop noticeable symptoms that include:
  • Greenish nasal discharge
  • Cough
  • High fever
  • Pneumonia
  • Respiratory difficulties
 

Early Symptoms

Canine Influenza Type A (H3N8) is a respiratory virus. Thus, early symptoms usually include nasal discharge, sneezing, coughing, and watery eyes. Some dogs never seem to progress beyond this stage, and naturally fight the virus off on their own. Others progress to advanced influenza in a matter of hours. Dogs who contract H3N8 almost always show symptoms within seven days. The H3N8’s cousin, H3N2, may cause similar symptoms up to 30 days after exposure. A 24– day quarantine period is recommended for any exposed dog to account for mutations.

Advanced Symptoms

Dogs who are untreated or who progress into advanced Canine Influenza are at a greatly increased risk for complications and difficult symptoms. The most common advanced symptoms include:
  • High fevers
  • Pneumonia
  • Bleeding in the lungs
  • Secondary lung infection
  • Liver, kidney, or heart complications
Early treatment and disease management is critical. The faster your dog is treated, the better your vet can manage his symptoms.

Disease Management

Managing Canine Influenza Type A in dogs starts with a positive diagnosis. That often includes blood work, though there are other more difficult ways to diagnose the disease. A dog who has been in contact with another pup who has been diagnosed recently almost certainly has the disease, and often, veterinarians will assume a diagnosis from that alone. If your veterinarian believes that your dog has contracted Canine Influenza, he or she will begin treatments to reduce symptoms and provide comfort care immediately. Many dogs benefit from baseline treatments like IV fluids, oxygen, and sedation. Dogs who become extremely sick may require broad spectrum antibiotics, painkillers, and other advanced treatments. Antiviral drugs have yet to show efficacy in the treatment of H3N8 and aren’t typically utilized. If your pup becomes mildly sick, keep her indoors. Provide her with a warm, snuggly place to rest that’s near the family, but free from stressors like loud children, other rambunctious pets, and strangers. A Snuggle Safe heat pad tucked into a dog bed will provide extra warmth when fevers strike, while an open window may provide comfort when she’s too hot (barring excessively cool drafts). Encourage your dog to drink plenty of water and give food as desired. If your dog begins to refuse either fluids or food, contact your veterinarian immediately. He or she can advise you on how to best prevent hunger or dehydration.

Current Outbreak Update

Canine Influenza Type A is changing. This is making it more difficult for veterinarians and pet owners to track the disease across the United States. The discovery of H3N8 in feline populations throughout the American Mid-West may also illustrate that the virus is mutating and changing form. It is more important than ever to be cautious about dog parks, play dates, shelters, boarding kennels, and multi-dog homes with regard to transmission. Recent updates in February of 2017 show a marked increase in Canine Influenza reports in nearly every single state. This includes diagnoses that demonstrate the presence of both H3N8 and H3N2. To track cases for your area, contact your veterinarian. Or, visit DogInfluenza.com’s tracker map directly.

A New Vaccine

An additional mutation of avian influenza was identified in 2006 in China and South Korea, and by 2015, the disease was found in dogs in Chicago. Since then, more cases have been reported throughout the United States. Medical researchers are trying to determine if the vaccine developed for the first avian influenza mutation is effective against the newest mutation. Today, the U.S. Department of Agriculture has approved a new vaccine for dogs that is now available at many veterinarian offices. Researchers do not believe that any type of canine influenza is transmissible to other species of animals or humans. The best way to prevent your dog from contracting Canine Influenza is to take precautions. For some pet owners, this will involve the currently-available vaccination. But the vaccine isn’t right for every pup. Contact your veterinarian for an evaluation of your pet’s health. Most importantly, ensure your furry friend is eating, drinking, and resting appropriately. A healthy pet has a much lower risk of contracting the disease.

PSA: Canine Influenza H3N2 Outbreak