Canine Influenza

Just as you and I are susceptible to catching the seasonal flu, so are our beloved dogs. While both humans and dogs are susceptible to influenza, there are many different strains of influenza, none of which can pass from humans to dogs or vise versa. So, if you are suffering from the flu, don’t worry about getting your dog sick; it ain’t gunna happen.

There are three types of influenza; influenza A, influenza B, and influenza C. Like our seasonal flu and the H1N1 pandemic of 2010, the canine influenza virus is also a strain of influenza A, the subtype being H3N8.

There are also strains of influenza that effects birds, seals, and horses; this is how we ended up with canine influenza.

In January of 2004, the first cases of canine influenza was reported at a Florida dog racing track. The equine flu carried by race horses was transmitted to the dogs at the race track. This is what is known as antigenic shift or, the process that allows viruses to jump from one species to another species.

From American Veterinary Medical Association: “CIV represents a very rare event in adaptive evolution; the entire genome of the H3N8 equine influenza virus was transferred to dogs, and the virus adapted to the canine species to emerge as a new canine-specific virus. Although the virus spreads readily from dog to dog, there is no evidence to support that it can be transmitted from dogs to humans.”

The time between exposure to the influenza pathogen and when a dog starts to exhibit symptoms (called the incubation period) is roughly two to four days. Unfortunately, during this time when the infected dog is showing no symptoms is also the time when there is more viral shedding, meaning the dog is most contagious at this time.

A dog can be exposed to the virus by means of respiratory secretions from an infected dog (such as sneezing or simple respiration). Transmission of the virus can also take place by means of infected items like toys, water and food bowls, collars, leashes, clothing, and other items in which a dog may come into contact.

Viruses are masters of survival. A common virus that causes most all gastroenteritis (stomach flu), norovirus, can actually survive on hands cleaned with alcohol based hand sanitizer. The canine influenza virus can survive on human hands for approximately 12 hours. The virus can survive on clothing for 24 hours and on surfaces for 48 hours.

So far, its hard to determine the prevalence of the virus since the symptoms seems to mimic those of kennel cough (infectious tracheobronchitis). A dog infected with CIV may show symptoms of lethargy; low fever; runny nose; soft, moist cough. A minority of infected dogs exhibit a dry hacking cough which would be more closely resemble kennel cough.

Since the symptoms for CIV and kennel cough are so similar, a diagnosis cannot be made by clinical signs alone. Only a blood test can accurately determine whether or not a dog is infected with CIV.

If you happen to fall ill and discover that your illness is viral (as opposed to bacterial), there really isn’t any treatment other than supportive treatment. A physician might prescribe Tamiflu but, more than likely, he/she will tell you to get a lot of rest and drink plenty of water. Similarly, dogs will be required to get rest and fluids to aide in their recovery.

Infected dogs should be closely monitored as there is a chance that dogs can acquire a secondary bacterial infection which could include pneumonia.

The canine influenza virus is one that is very virulent, meaning it is highly contagious. In fact, nearly every dog that comes into contact with the virus will become infected, while nearly 20% of infected dogs will not demonstrate symptoms.

The terms morbidity and mortality are used in pathology (the study and diagnosis of disease) and epidemiology and can case a bit of confusion. So let me break it down: Morbidity rate describes the percent of subjects who, when exposed to the pathogen, will contract the pathogen. Mortality rate demonstrates the percent of infected subjects that will die due to illness.

The canine influenza virus has a morbidity rate of 80% (this is very high due to CIV being a new virus and dogs not having immunity), and the mortality rate 1-5% (low for influenza).

It should be noted that mortality is higher amongst dogs with secondary infections such as pneumonia.

As we discussed, the CIV is quite virulent but, it’s not exactly widespread. This virus remains active in pockets of the United States where dogs are confined to tight spaces such as shelters, dog parks, kennels, boarding facilities, veterinarian clinics, etc. As of September 2011, the virus has been found in 38 states which include: WA, OR, CA, ID, WY, NV, UT, AZ, CO, NM, KS, OK, TX, AR, IA, WI, IL, FL, GA, AL, SC, NC, TN, KY, WV, VA, OH, PA, DE, MD, NJ, NY, CT, RI, MA, NH, VT, and ME.

Currently there exists an effective vaccine for CIV. The vaccine has shown to significantly reduce the severity and duration of the influenza virus so, dogs that have become vaccinated and still become infected with the virus will have considerably reduced symptoms.

The American Veterinary Medical Association describes the CIV vaccine on their website:

“The canine influenza vaccine is a “lifestyle” vaccine, and is not recommended for every dog. In general, the vaccine is intended for the protection of dogs at risk for exposure to the CI virus, which include those that either participate in activities with many other dogs or are housed in communal facilities, particularly where the virus is prevalent. Dogs that may benefit from canine influenza vaccination include those that receive the kennel cough (Bordetella/parainfluenza) vaccine, because the risk groups are similar. Dog owners should consult with their veterinarian to determine whether their dog’s lifestyle includes risks for exposure to the CI virus, and if the vaccine is appropriate for their dog.”

I have spotted several blogs that seem distrustful of the CIV vaccine and will tell you not to vaccinate your dog due to supposed “lack of safety”. At the bottom of this article I link to a few extensive studies regarding the excellent safety and effectiveness of the CIV vaccine. As I quoted from the AVMA, consult your veterinarian when making a choice to vaccinate your dog as not all dogs require that vaccine (dogs that don’t socialize or do not have a risk for exposure).

References and Resources:

PubMed articles showing strong efficacy for CIV vaccine:

When can a puppy leave its mother?

I was recently asked to cover a topic that seems to be fervently debated; the age at which a puppy can leave its mother.

From what I can tell, there are three schools of thought on the issue.

1) A puppy can leave its mother at six weeks.

2) A puppy can leave its mother at eight weeks.

3) A puppy can leave its mother at twelve weeks.

In order to decide which one of these is the best time to bring a dog home, we should probably know something about a puppy’s development.

Here is an abbreviated timeline of puppy development:

Neonatal Period: Birth to Two Weeks

At this point, puppies have their eyes and ears closed. They stay close to their littermates and mother.

Transitional Period: Two Weeks to Four Weeks

Eyes and ears open up, marking the further development of sight and hearing. Puppies are testing their ability to walk, wag their tail and bark.

Socialization Period: Three Weeks to Twelve Weeks

Puppies are influenced heavily by their mother and fellow littermates. Puppies start venturing out into their environment and learn of fellow companions; both human and canine.

At three to six weeks, a puppy is learning discipline from the mother and shows submission to her leadership. By interacting in play with littermates, a puppy obtains an understanding of pack hierarchy.

At seven to nine weeks a puppy has fully developed senses.

At eight to ten weeks, puppies become better at controlling their bladder and bowel. At this time, puppies are ready for house training (although some say that house training needs to wait until after twelve weeks).

At eight to eleven weeks, puppies can experience the fear imprint stage of development where they are extremely sensitive to upsetting events. During this stage, puppies can develop a fear of certain objects that affects them for their entire life.

So, when can you take your puppy home?

Well, people who say a puppy can leave its mother at or before six weeks are few and far between. At six weeks, and even eight weeks, puppies are still learning from their littermates and mother. If a breeder tells you that your puppy can come home at six weeks or even earlier, this might be an indicator that your breeder isn’t very professional since your puppy will be missing out on very important time with it’s mother.

People who want to wait until a puppy is twelve weeks old to take him/her home are going to get a puppy that has the capability to hold its bladder, has had quality time with littermates and mother, has gotten passed the fear imprint stage, and is ready to be house broken.

From my deduction, I have come to the conclusion that taking a puppy home somewhere between eight to twelve weeks –but no earlier than eight weeks– should be fine. Obviously, you should always consult your breeder and get their opinion but, as I mentioned, if your breeder tells you to take the puppy home around six weeks, be skeptical.