14 JunA primer on the dog flu outbreak in NYC

You've probably heard about the dog flu that has recently been felling dogs all over NYC. Below is a primer on all you need to know. Also make sure to check out our recent podcast episode on the subject (“What you need to know about the dog flu“) featuring an interview with Dr. Andrea Y. Tu of Park East Animal Hospital and Veterinary Behavior Consultations of NYC.

What is the flu?

There are two strains of the dog flu about which we are currently concerned. H3N8 and now H3N2

H3N8 influenza was first identified in 2004 in racing greyhounds in Florida, and is believed to have jumped from horses to dogs.

H3N2 is believed to have originated in birds and was first detected in dogs in South Korea in 2007. It was identified in March 2015  in the Chicago area; it most likely spread from dogs rescued from South Korea and brought to the US for adoption. Prior to this, reports of canine H3N2 influenza virus were restricted to South Korea, China and Thailand. The virus has also been known to spread to cats.

In May 2017, canine H3N2 influenza was diagnosed in dogs in Florida, Georgia, North Carolina, South Carolina, Texas, Kentucky, Tennessee, Missouri, Louisiana, and Illinois. This was the same strain of H3N2 involved in the 2015 outbreak in Chicago.

There is no evidence that either strain of canine influenza (H3N8 or H3N2) can infect humans, but it's possible it could morph (remember the swine flu and bird flu didn't originally infect us, either!).

How does it spread?

Both strains are transmitted via respiratory secretions resulting from licking, coughing, barking, sneezing, sharing toys, bowls, etc. The virus can survive up to 48 hours on objects, and up to 24 hours on clothing, and 12 hours on hands.

What are symptoms to look out for?

Fever, lethargy, loss of appetite, nasal or ocular discharge, coughing,

How can I tell if my dog has been exposed to the virus?

Well… you can't. H3N8 has an incubation period of 1 to 5 days; clinical signs, if they appear, in most cases will be seen 2 to 3 days after your dog has been exposed. Dogs are most contagious during this incubation period, but may not start showing respiratory signs for up to 8 days after they've become infected. A dog may show no signs of illness, but have an infection and may still be shedding the virus. If your dog is exposed to canine influenza virus, there is nearly a 100% chance he will become infected; 20% of infected dogs will not show any clinical signs of disease.

Is it deadly?

Potentially, yes. However, Dr. Tu and other sources we consulted are not aware of any recent fatalities due to these strains of the flu in NYC. It's estimated that the chance of death following infection are roughly one in ten.

Should I get my dog vaccinated?

Unless you and your dog live in a remote location far away from other dogs, you should absolutely get your dog vaccinated. Even if you have a dog who doesn't leave your home, the virus can still live on you. Fortunately, there is a bivalent vaccine (one that will protect your dog against both strains) that can be obtained from any local veterinarian. Once the vaccine is received, a booster is required two weeks later. The side effects from receipt of the vaccine are generally inconsequential. It's possible that a vaccinated dog may still get infected by the viruses, but the vaccines will (at the very least) reduce the flus' severity and duration. Puppies over 7 weeks old can get the vaccine, too.

What if my dog gets infected?

Infected dogs usually show signs of illness for two to three weeks, and should be kept away from other dogs for at least a month. When bringing a dog who is infected (or who you are concerned might be infected) to the vet, notify them in advance as they will probably clear the waiting room in anticipation of your arrival. Because these infections are viral, there is no cure; care is supportive. Dogs must be kept well hydrated and may need to receive fluids intravenously, they must get enough to eat and may have to get a feeding tube to insure proper nutrition. Infected dogs may receive antimicrobials for secondary bacterial infections, and non-steroidal anti-inflammatory medication to reduce fever and inflammation.

But I can still take my dog to the park, right? 

Unless your dog is fully vaccinated (has received the initial shot and the booster), it's probably best to avoid dog parks, dog daycares, and anywhere else where there is a lot of dog traffic. However, unfortunately, even vaccinated dogs can still get sick.