Canine Influenza Is Very Contagious

Canine influenza is extremely contagious among dogs and risk is highest where dogs congregate, such as dog parks. Joy Brown/Shutterstock

Q: My dog’s annual physical is coming up soon, and my veterinarian is sure to recommend the flu shot, which I’ve declined in the past. I’m rethinking that after a friend’s dog came down with the disease. Please tell me about dog flu.

A: Dog flu, formally known as canine influenza, was first recognized in the United States in 2004. It is caused by two strains of the influenza A virus: H3N8 and the more common H3N2.

Canine influenza is extremely contagious among dogs. Risk is highest where dogs congregate, such as doggy day care facilities, dog parks, grooming parlors, training classes, dog shows, and boarding kennels.

Even before clinical signs appear, an infected dog can transmit the virus through the mouth, saliva, nose, and nasal droplets. The virus also spreads through contaminated water and food bowls, bedding, and other items.

A dog becomes infected within a few hours of exposure and shows clinical signs two to five days later. Clinical signs include coughing, sneezing, loss of energy and appetite, fever, and discharge from the nose and eyes. Pneumonia and other severe clinical signs occur in 10 percent to 20 percent of flu patients. The disease is fatal in 1 percent to 5 percent.

Even more worrisome is that 20 percent to 50 percent of exposed dogs show no clinical signs but become asymptomatic carriers that infect other dogs.

Both asymptomatic carriers and dogs sick with influenza can transmit the virus for up to four weeks and must be isolated from other dogs for at least that long. These dogs should also be kept away from cats, ferrets, and guinea pigs, though the virus is not as contagious to these species as it is among dogs. Fortunately, canine influenza does not infect humans.

The vaccination you mention protects against both influenza strains, decreasing the severity of the disease if it does strike. The initial vaccination is boosted three to four weeks later and then annually.

Q: I recently took my cat, Whiskers, to the veterinarian for a medical problem. The vet examined him and prescribed medication, but he didn’t explain much.

Whiskers is fine now, but I am frustrated with the poor communication. How should I handle this in the future? I don’t want to change veterinarians because I think this one is good and the others are farther away.

A: I’m happy to hear Whiskers is doing well after his illness but disappointed to hear that you and his veterinarian did not communicate well. That may be because some veterinarians communicate better with pets than humans.

You can help improve the dialogue by giving your vet a good history and asking the right questions. The history is the story of what’s happening. Your vet relies on the history and physical examination to formulate a list of possible diagnoses that guide further workup and treatment.

In one human medicine study, the patient’s history was responsible for 76 percent of the accuracy of the diagnosis. So it’s important that you share all potentially helpful information in a succinct, organized manner.

Your history should begin with the date Whiskers was last normal. Explain the onset of each problem in the order it developed. Describe any diet changes, medications, or other treatments you tried.

After your veterinarian examines Whiskers, ask what he found, what he thinks is causing the problems, and what he recommends next.

If your veterinarian talks about further testing and treatment, ask about your options. You may feel more comfortable doing all suggested diagnostic testing from the start, or you might prefer to proceed in a step-by-step manner based on how Whiskers responds to treatment.

If the condition is complicated, request that your veterinarian write down the diagnosis. Ask for written information or consult VeterinaryPartner.vin.com for details about the condition.