The new strain of Canine Influenza Virus (CIV), referred to as H3N2, has now been confirmed in North Carolina. As the virus continues to spread within the United States, the number of sick dogs increase. Therefore, the following information is important for all veterinarians and clinic staff.

Background Information on CIV

What is known:

• CIV is a community acquired illness of increasing prevalence.
• It is highly contagious with limited pre-existing immunity in the dog population because it is a new disease
• The virus occurs year-round and spreads via:
• Airborne
• Physical contact
• Human contact
• Increased risk for exposure is found in locations such as:
• Veterinary clinics, boarding facilities, shelters, breeding kennels, pet stores, doggie day cares, training facilities, grooming clinics, dog parks
• The first case of CIV, strain H3N8, was reported in 2004; a new strain, H3N2, was recently confirmed in Illinois, continued to spread across the US, and has now been confirmed in several states.
• There is a vaccine for the H3N8 strain of CIV, Nobivac Canine Flu H3N8.  However, to date, it has not been determined if this vaccine is cross-protective with the H3N2 strain that has recently emerged.
• Animals that have been vaccinated for other respiratory infectious pathogens, and not CIV specifically,  are still susceptible to  canine flu.

Clinical Signs of CIV

• Typically begin within 4 to 5 days after exposure
• However, CIV shedding can occur prior to the appearance of clinical signs and the disease can rapidly spread before disease is diagnosed.
• Presents with clinical signs similar to infectious tracheobronchitis, caused by:
• Bordetella bronchiseptica
• Parainfluenza
• Canine Adenovirus Type 2
• Canine respiratory coronavirus
• Canine herpes virus
• Difficult to distinguish clinical signs of CIV from other respiratory diseases because the symptoms are so similar
• If CIV is reported in your area, and a dog presents with traditional kennel cough clinical signs, it is best to proceed with caution and isolate that animal while thoroughly disinfecting surfaces that were in contact with the dog.
• Serology should be completed to confirm a diagnosis of CIV infection.

Mild CIV Clinical Signs

• Mild upper respiratory tract infection that presents with:
• Dry, nonproductive cough or a soft, moist cough
• Nasal discharge
• Initially clear
• Quickly becomes mucopurulent
• Low-grade fever
• Anorexia

Nasal discharge usually resolves with antibiotic treatment, but coughing may last for several weeks, regardless of the treatment regimen.

Severe CIV  Clinical Signs

• Severe upper respiratory tract infection that presents with:
• Pneumonia
• Nasal discharge
• Mucopurulent
• Bloody
• High fever (104-106° F)
• Increased respiratory rate

Secondary infections are connected to severe cases of CIV; the recovery from this level of infection may be prolonged, and there is a risk death may occur.

Exposure vs. Development of Infection

It is estimated that of the dogs exposed to CIV:

• Between 80 to 90% will develop a mild clinical infection.
• Up to 20% will develop a severe clinical infection.
• About 10 to 20% of animals that contract CIV will never show clinical signs, but can still pass on the infection to other dogs.

Risk Factors

Factors to consider that may place a dog at higher risk for developing a severe case of CIV include:

• Age
• Very young
• Very old
• Health issues
• Poor body condition
• Debilitated
• Immunocompromised
• Concurrently exposed to secondary bacterial or viral pathogens

Healthy dogs infected with CIV will most likely only develop a mild case of the disease, but clinical studies have found that even healthy dogs can develop a severe case of CIV.

Prevention by Testing and Vaccination

To fight against the advancing spread of CIV, the following points should be remembered:

• CIV sheds for 7-8 days post exposure.
• Clinical signs can begin around days 3-4, placing many animals at risk of exposure before disease is recognized.   The overlap for 2-3 days before the shedding stops provides only a small window of opportunity for capturing a positive viral sample to definitively diagnose CIV.
• CIV spreads fast because dogs can shed and spread the virus without exhibiting any symptoms.
• It is imperative to take mucosal swabs of an animal presenting with respiratory issues.
• CIV cannot be confirmed without diagnostics; swabs should be handled appropriately and sent for testing:
• Merck Animal Health is currently working to facilitate testing to identify and track CIV. The samples collected by Merck are sent to Cornell for confirmation.
• An independent lab, IDEXX, is also able to test for the H3N2 strain of CIV.

Vaccinate effectively for other Canine Infectious Respiratory pathogens:

• 3-way intranasal vaccines such as Nobivac IntraTrac 3 and Bronchi-Shield 3  provide mucosal protection against Bordetella, Parainfluenza, and Adenovirus, which can protect against other respiratory diseases with a fast onset of immunity, lessening the risk of secondary infections in the face of a CIV challenge.
• Nobivac Canine CIV H3N8 vaccine
• Protects against the H3N8 strain but not determined if offers any protection against the H3N2 strain.
• What is known is that none of the CIV H3N8 vaccinated dogs have contracted the CIV H3N2 flu thus far.
• In an effort to protect and support the veterinarian community, Merck is guaranteeing the Nobivac® H3N8 vaccine for use with either strain of CIV. Details of the guarantee are available on their website.

Prevention Strategies for Staff

Strategies for preventing the spread of CIV within your clinic should be determined and protocols established to include:

• Isolation
• Animals suspected to be infected with CIV should be kept away from other dogs
• Separate entrance/exit to facility should be utilized.
• Animals should be evaluated in a separate examination room, preferably one that does not have a common air space.
• Safety clothing should be worn: gloves and gown at minimum.
• Disinfectant footbath should be available for exiting the examination room or throwaway shoe covers should be provided.
• Handling of billing, scheduling, and other office staff needs should be completed in a manner to avoid the spread of virus particles where healthy animals frequent.
• Disinfectant Needs
• CIV can be killed by commonly used clinic disinfectants, for example:
• Bleach solutions at 1:30 dilution
• Recommended contact time of at least 10 minutes
• Following examination:
• Disinfect the entire room from floor to ceiling, including equipment and furniture.
• Staff should thoroughly wash hands with soap and water or use an alcohol-based sanitizer.
• Client Information Needs
• Advise clients of the ways that the virus is passed to a healthy animal so they recognize their responsibility to minimize the spread of exposure, for example:
• Keep pet isolated from other dogs until animal is completely recovered.
• Regularly wash hands, food, and water bowls with soap.
• Before handling other animals, change clothing and shoes.
• Avoid taking pet to any activity or facility where another dog could be exposed if their pet is coughing.

The sum of these tips can help veterinary practices and pet parents break the cycle of transmission of CIV. If you have any questions regarding canine influenza virus, please contact your Covetrus representative at 855.724.3461 today.