By Dr. Becker
With winter on the way, for the next few months we can expect to be bombarded with warnings about the influenza virus and the need for flu shots. Just as Dr. Mercola advises against human flu vaccines, I recommend avoiding canine flu vaccines as well (more about that later). It's important to note that human and canine flu viruses are different, and there's nothing to suggest that people can contract the flu from their dogs.
Types of Canine Flu Viruses
The canine influenza virus (CIV) is a relatively new virus and is part of the canine infectious respiratory disease complex, also known as kennel cough. In the U.S., two strains of canine influenza have been reported, H3N8 and H3N2. Flu viruses are classified by two large surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). That's where the "H" and "N" designations originate. There are 16 H and nine N subtypes known.
Strain H3N8 was initially an influenza virus occurring in horses. The equine virus mutated and can now be transmitted among dogs as well. Strain H3N2, new in this country as of two years ago, was originally identified in southern China and South Korea and is derived from a strain of avian flu that now has the ability to infect dogs.
How Dogs Contract and Spread the Flu Virus
CIV is passed between dogs living in or visiting settings such as animal shelters, boarding kennels, doggy day care centers, dog parks, grooming or veterinary facilities, pet stores and canine sports or other competitions. Outbreaks typically result from direct dog-to-dog contact, contact with contaminated surfaces or aerosol transmission of the virus through sneezing or coughing.
Generally speaking, CIV is transmitted by close contact with an infected dog, often in a restricted space. Because infected dogs shed a relatively low amount of the virus, casual contact isn't a huge concern.
Dogs are most contagious during the two- to four-day incubation period for the virus. During this short window of time, dogs are infected and shedding the virus in their nasal secretions, but are not yet showing signs of illness. Almost 100 percent of dogs exposed to CIV will become infected, and the majority (80 percent) will develop flu symptoms. Fortunately, the death rate is low (less than 10 percent). All dogs are susceptible regardless of age, gender or breed.
Assessing Your Own Dog's Risk
CIV is primarily associated with overcrowded conditions like those found in some shelters, kennels and dog racing facilities. It's unlikely most family dogs will be in a situation to contract the virus, but even if yours does, chances are she'll recover quite nicely without medical intervention, thanks to a healthy immune system.
It's rare that a dog requires hospitalization for CIV. Serious illness usually occurs only in very young puppies, geriatric dogs or those who are immuno-suppressed, highly stressed or otherwise debilitated.
Symptoms to Watch For
The onset of symptoms of canine influenza is two to three days after your dog has been infected. Virus shedding peaks at three to four days post-infection, and the illness declines rapidly once your dog's immune system responds to the presence of the virus. Common symptoms of a CIV infection last from one to two weeks and include:
- Paroxysmal coughing (fits of coughing)
- Hacking cough or gagging
- Rhinitis (stuffy, runny nose)
If your dog is still coughing after 10 days, he's no longer infectious. The cough is likely due to damage to the respiratory tract. A CIV infection by itself is not usually serious, however, the infection plus the presence of other respiratory viruses can result in secondary bacterial pneumonia.
In some animals, especially puppies with undeveloped immune systems, symptoms can be quite severe, including the four mentioned above plus anorexia (loss of appetite), lethargy, fever and breathing difficulties. In these patients, the illness may also hang on longer.
Diagnosing Canine Flu
CIV is diagnosed based on a physical examination of your dog, her symptoms and diagnostic test results. If your veterinarian suspects the flu, chest x-rays may be recommended to rule out other respiratory diseases prior to testing for influenza.
Since CIV is often present alongside other respiratory pathogens, in the early stages of illness it can be beneficial for your vet to run a canine respiratory PCR (polymerase chain reaction) panel, which tests for adenovirus, distemper, parainfluenza, respiratory coronavirus, pneumovirus, Bordetella bronchiseptica and Mycoplasma cynos along with matrix influenza PCR.
The panel, which is offered by Cornell's Animal Health Diagnostic Center (AHDC) and IDEXX Laboratories, can also identify influenza positive samples as either H3N8 or H3N2. Dogs who've been symptomatic for longer than seven days should be diagnosed using an antibody test, as by this time, the virus itself is usually undetectable. The AHDC has developed an assay that detects antibodies to the newer H3N2 virus strain.
The traditional veterinary approach to treating canine influenza includes the short-term administration of antibiotics and anti-inflammatory doses of glucocorticoids to help relieve coughing. These drugs don't cure the infection or shorten the duration of the illness, and since they carry side effects, I typically don't recommend them.
Other traditional therapies can include antitussives (hydrocodone, butorphanol) as long as no bacterial infection is present, and aerosol or nebulizer delivery of antibacterials in patients with secondary bacterial infections. I recommend diffusing high-quality eucalyptus oils as well.
Sick dogs should be isolated and given supportive care in the form of hydration, caloric support and supplemental oxygen therapy as necessary. It can also be beneficial to bring your dog into a warm, humid environment for brief periods, for example, into the bathroom while you shower.
Neck collars must be replaced with head collars (e.g., the Gentle Leader), dogs shouldn't be exposed to smoke or smog, and barking should be discouraged. Holistic supportive care can include adding astragalus, liposomal vitamin C, cat's claw and Echinacea to your dog's protocol, along with homeopathic nosodes and other natural remedies (such as slippery elm tincture for sore throats) for symptom relief.
Why I Don't Recommend Canine Flu Vaccines
I don't recommend canine influenzas vaccines because they don't prevent infection. The vaccine may reduce viral shedding once infection is present, and may lessen the severity of symptoms and their duration, but it does not keep your dog from acquiring CIV.
Too many vaccines, in particular noncore vaccines (any canine vaccine other than distemper, parvo, adenovirus or rabies) like the one for CIV, can seriously compromise your pet's immune system, affecting its ability to protect your dog naturally from pathogens like the influenza virus. In addition, noncore vaccines have proved to be less safe in terms of adverse reactions than core vaccines.
How to Help Your Dog Avoid the Flu
If your pet is exposed to the canine influenza virus, as long as his immune system is healthy, he'll either be asymptomatic (show no symptoms), or he'll recover quickly without the need for medical care. To keep your pet's immune system in flu-fighting condition:
- Feed a nutritionally balanced, species-appropriate, fresh food diet
- Avoid unnecessary vaccinations and overuse of veterinary drugs and chemical parasite and pest preventives
- Reduce the environmental toxins your dog is exposed to, which will in turn lesson his toxic burden and biological stress
- Talk to your holistic veterinarian about natural immune boosters like turmeric, oregano, fresh garlic, useful herbs and virus-fighting essential oils