CANINE INFLUENZA (DOG FLU)
The virus can cause coughing, high fevers, nasal discharge and a fatal pneumonia.
The Canine Influenza Virus is considered highly contagious. It has been suggested that while it is 100% infectious, at least 80% of dogs exposed to the virus will develop an infection. This is a virus that affects everyone and it is not choosy as to whether the immune system is compromised or not.
The number of dogs at risk from dying from this virus is estimated to be around 8%.
According to Dr. Dick Slemons, an authority on influenza viruses from the Ohio State University College of Veterinary Medicine, the disease is associated most often with dogs housed in a high-density population such as: boarding kennels, grooming facilities, breeding facilities, daycares, and animal hospitals. The infectious agent is thought to be transmitted through the air or by contact with contaminated surfaces. The virus has been documented in shelters, boarding facilities, pet stores and dog tracks. The incubation period (time from exposure to symptoms) is estimated to be 2 -5 days. If a human is exposed, the virus may live on their clothing for several hours, meaning they can take it home to their canine family members.
The origin of the virus is thought to be mutated from an influenza virus that affects horses. The virus was discovered by Dr. Cynda Crawford, an immunologist at the University of Florida College of Veterinary Medicine, who began investigating the first outbreak at a racetrack in Jacksonville, FL in January 2004. The virus made national media attention after Dr. Crawford and colleagues published an article in the September 26, 2005 edition of Science Magazine entitled "Transmission of Equine Influenza Virus to Dogs".
It is often mistaken for infections caused by kennel cough (Bordetella bronchiseptica/parainfluenza virus complex.) The virus may appear similar to kennel cough, which is a highly contagious inflammation of the trachea (windpipe) and bronchial tree caused by a contagious virus (adenovirus, parainfluenza virus, canine distemper virus) or bacterium (Bordetella bronchiseptica). However, with most cases of kennel cough, a mild to moderate cough without other symptoms is usually self-limiting; however, occasional cases become lingering and cause chronic bronchitis. With this new virus, the cough is often associated with high temperatures, coughs and nasal discharge.
There is no evidence that the dog virus can spread to humans, cats or other animal types. So far, it is believed that the virus is species specific and only spread dog to dog.
What to Watch For
Watch for a variety of symptoms that can vary in severity.
· Signs of upper respiratory problems such as conjunctivitis (irritated eyes), rhinitis (runny nose) or sneezing may be observed.
· Cough. The classic symptoms are coughing that worsen with activity or excitement and can persist for minutes. If secondary bacterial pneumonia develops, the dog often shows signs of illness such as loss of appetite, depression, or fever.
· Fever (high as 106 degrees F)
· Difficulty breathing
· Loss of appetite
Any of these signs should prompt a visit. Make an appointment to see the veterinarian to be certain pneumonia has not set in. Symptoms can last for up to four weeks.
A complete medical history may help to reveal recent exposure to a kennel or other dogs. However, it will be difficult in some situations to differentiate this virus from the common "Kennel Cough" virus mentioned above. Diagnostic tests are needed to recognize it and exclude other diseases. These tests may include:
· A chest X-ray may be recommended to determine if pneumonia is present.
· Routine laboratory blood tests-a complete blood count (CBC) or blood chemistry panel is not necessary unless your pet is showing signs of generalized illness, fever or loss of appetite.
· A fecal flotation should be done to exclude intestinal parasites.
· Blood titers and PCR testing – Testing for the virus is being done through Cornell School of Veterinary Medicine diagnostic lab. These are frustrating though and may not be used by the veterinarians due to the fact that by the time the patient is seen, they are no longer shedding the virus, which makes a PCR a difficult diagnostic tool. Blood testing recommendations to determine antibody levels include that a sample be submitted during the first week of illness (acute sample) followed by another sample 2 – 3 weeks later (convalescent sample). Diagnosis is based on a four fold increase in antibody titers from acute to convalescent phase. Antibodies are generally not detectable during the first week of clinical signs but are detectable after the first week and for up to 2 years after infection. If an acute sample is not available, exposure can be confirmed by the presence of antibodies in a convalescent sample. Many veterinarians may elect not to do the antibody testing either, unless requested by a client to confirm diagnosis because diagnosis will not alter the treatment course.
Therapy is controversial because in the early stages it is difficult to determine if this virus is the new virus or kennel cough virus. Most infected dogs will recover with no treatment. A small percentage of dogs will develop severe and possibly fatal pneumonia. It has been recommended that all dogs with a fever and cough should have appropriate blood tests submitted and treated aggressively to minimize fatalities. Treatment may include the following:
· Antibiotics are used in some patients, especially if a secondary bacterial infection is likely.
· Intravenous fluid therapy has been used and associated with improvement and less fatalities in affected pets.
· Antiviral drugs such as amantidine and tamiflu may be effective, however, their usefulness in this syndrome may be limited as they are most effective if given before infection or exposure or in the very early stages of infection.
· Cough suppressants may be appropriate for some pets. Your veterinarian can discuss the pros and cons of this treatment. Injections or pills (butorphanol) are often used, but occasionally, a stronger medicine is needed (codeine-related) to break the cough cycle. Don't use over-the-counter human medicine without first speaking to your veterinarian.
· Dogs should be kept in isolation if treated in the hospital and very good disinfection measures need to be used.
For more information on Home Care and Prevention go to:Canine Influenza Virus (Dog Flu)
If your dog is infected, to prevent the spread of the virus, keep your dog away from other dogs for at least one week. In addition, do the following:
· Limit exercise and enforce periods of rest; don't exercise or play with your dog. Activity often initiates periods of loud, uncomfortable coughing.
· Encourage adequate fluid intake to maintain hydration. Provide soft food if dry food irritates the throat.
· If your dog normally wears a restraint collar, remove it or replace it with a harness to decrease airway irritation.
· Avoid environmental stresses including house dust, vapors, chemical fumes and tobacco smoke.
· To mobilize secretions and reduce coughing, provide humidified air (e.g. a vaporizer in the dog's room or in a steamy bathroom for one or two hours).
There is a new vaccination to help protect your canine family members from becoming ill. This requires a vaccination with a boost 3 weeks later. Then the vaccination is administered annually.
Other ways to help prevent infection are to minimize exposure to other pets, especially in high-density situations such as kennels, doggie parks, or puppy class. May sure your pet is kept away from any symptomatic coughing dog. Take special care if your dog is a puppy or older as they are at higher risk for difficult infections.
The virus is spread in the air by infected dogs, through contamination of objects in the environment and by people that may interact with infected and uninfected dogs.
The virus is killed by routine disinfectants such as quaternary ammoniums or a 10% bleach solution. Thorough cleaning of crates, cages, bowls, bedding, floors and other surfaces is recommended to prevent transmission to other dogs. Clothing, equipment, surfaces, and hands should be cleaned and disinfected after exposure to dogs showing signs of respiratory disease to prevent transmission of infection to susceptible dogs. People interacting with infected dogs are advised to wash their hands well before and after interacting with infected dogs. Clothing can be effectively cleaned by using a typical laundry detergent at normal washing temperatures.
Because the virus is spread in the air, avoiding being around dogs that are coughing is the best prevention at this time.
If your pet begins coughing, call immediately to schedule an appointment.
For more information access the center for disease control website at www.cdc.gov/flu/canine