UPDATE ON CANINE INFLUENZA IN TENNESSEE Staci Cannon, DVM, MPH, DACVPM, DABVP (Shelter Medicine Practice)
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What is Canine Influenza? Highly contagious respiratory infection of dogs Caused by influenza A virus H3N8 H3N2 Not seasonal Vaccines available No evidence of transmission from dogs to humans
History H3N8 First reported in 2004 in Florida in racing Greyhounds This strain developed from an equine H3N8 influenza strain Endemic in some shelters in the Northeast US H3N2 Spring 2015: >1000 dogs were affected in midwest US Asian origin likely arose through direct transfer of avian influenza Infected thousands of dogs in more than 30 states Recent outbreak from Florida/Georgia began in May 2017
Who is susceptible? All dogs, regardless of breed, age, or health status, are susceptible due to lack of immunity Especially if not previously vaccinated for canine influenza Risk depends on lifestyle Group event participation Housed in communal facilities
Transmission CIV is spread through aerosolized respiratory secretions and direct contact or fomites Aerosolized respiratory secretions can travel up to 20 feet from coughing, barking, and sneezing Contributes to rapid increase in coughing dogs in shelters Virus is viable on surfaces for 48 hours, clothing for 24 hours and hands for 12 hours
Clinical Signs Fever Cough Sneezing Nasal discharge Loss of appetite, lethargy Virtually all exposed dogs will become infected, 80% show clinical signs Most dogs recover in 2-3 weeks Can progress to life-threatening pneumonia, due to secondary bacterial infections
Diagnosis Collect nose and throat swabs to submit for Respiratory PCR testing at diagnostic lab Collect swabs from dogs that have been sick for less than 4 days https://vetmed-maddie.sites.medinfo.ufl.edu/files/2014/10/collection-of-swabs-for-diagnosis-of-respiratory-pathogens-by-pcr.pdf
Treatment ISOLATION Viral infection = supportive care Secondary bacterial infections are very common Treated with broad spectrum antibiotics Fluid therapy, nutritional support, anti-inflammatories Most dogs recover within 2 weeks without complications About 20% of infected dogs can progress to pneumonia Can be life-threatening May require hospitalization
Vaccination Lifestyle vaccine intended for dogs at risk ( social dogs ) Boarding/Daycare Dog shows Similar risk profile to Bordetella/ Kennel Cough Vaccines available for both strains Killed vaccine, requires 2 doses Immunity develops over 3-5 weeks Vaccination reduces the severity and duration of clinical illness
Sanitation Routine infection control precautions are key to preventing spread of viral disease within shelters CIV is easily killed by disinfectants Shelters should implement protocols for routine sanitation of kennels, bowls, surfaces, floors, ACO trucks, and all fomites (handling equipment, medical equipment, scales, etc.) Good opportunity for a sanitation audit shadow your staff Require proper hand sanitation by staff and volunteers Routine laundering of clothing, bedding, and toys
Outbreak Management Diagnosis and Isolation: Isolate all sick dogs for 4 weeks Incubation time < 1 week Shedding or contagious time = 3 to 4 weeks Most, if not all, dogs become infected if exposed Most sick dogs recover in about 2 weeks with no further health complications Identification and Management of Exposed Animals: Quarantine all exposed dogs for at least 1 week, preferably 2 weeks Environmental Decontamination: CIV is readily killed by common disinfectants Protection of Newly Admitted Animals: Prevent exposure of new dogs to sick dogs and dogs already exposed (quarantine population) Documentation and Communication
This sounds like kennel cough? Clinical signs are identical to other respiratory pathogens Kennel cough or canine infectious respiratory disease, is caused by one or more bacterial or viral infections, including Bordetella bronchiseptica and parainfluenza virus Laboratory diagnosis is required Be suspicious if you experience a rapid increase in sick dogs in your population Sick dogs make up more than 50% of population Some dogs develop high fevers and pneumonia Shelter staff may report their dogs at home are coughing Stay in touch with other shelter directors, boarding kennels, and veterinarians in your area about case incidence Monitor media reports
What about cats? H3N2 has caused infection and respiratory illness in cats but less frequently. Some evidence that guinea pigs and ferrets can become infected Signs of infection are similar to those seen in dogs. Upper respiratory signs, lethargy, lip smacking, salivation
Canine Influenza Fact Sheet for Veterinarians What is canine influenza? Canine flu is a highly contagious viral infection that causes illness in 80% of exposed dogs. Even seemingly healthy dogs can shed the virus. There are currently two virus subtypes of concern: H3N2 and H3N8. Both subtypes can cause high morbidity and low mortality (~3%-5%). The virus is not known to be a risk to humans, although close contact with any animal infected with an influenza virus is not recommended. Transmission Flu virus is spread through direct contact and aerosolized particles that can travel up to 20 feet. Fomites, such as stethoscopes, food bowls, scrubs, and examination tables may retain infectious virus for 24-48 hours. People can also carry the virus on their hands for up to 12 hours. Flu viruses are easily inactivated by disinfectants, such as 1:30 parts bleach to water. Clinical Signs Clinical signs include nasal/ocular discharge, coughing, sneezing, lethargy, fever, and anorexia. Some dogs may have more severe clinical signs of pneumonia. Diagnosis Canine influenza virus may cause clinical signs similar to other respiratory pathogens, so diagnosis is made on the basis of results of virus isolation, PCR, immunoassays, or serology. Nasal or oropharyngeal swabs or transtracheal wash fluid can be submitted to the University of Tennessee College of Veterinary Medicine, the C.E. Kord Animal Health Diagnostic Laboratory, IDEXX and other commercial diagnostic laboratories. Detection of the virus is more successful early in the course of disease. Treatment Treatment consists of supportive care and may include antibiotics, NSAIDs, and fluids, depending on the case. Recovery usually takes two to three weeks. Prevention Vaccination may be indicated in dogs that are socially active, being boarded or groomed, or have underlying disease such as heart or respiratory disease. Elderly or immunecompromised dogs may also benefit from vaccination. Virus may be shed for up to 28 days, so four weeks of isolation is recommended for infected dogs. Proper hand washing and biosecurity measures, such as asking clients to stay in their car when they arrive at the clinic, using a side entrance, full body PPE for staff, and disinfecting the room, equipment, hallway, and entrance, can stop flu from spreading. Cats Cats have been known to be infected in shelter settings. No vaccine exists for cats at this time. There have been no documented deaths in cats due to canine influenza. Clinical signs include upper respiratory signs, lethargy, lip smacking, and salivation. Canine flu is not reportable, but all animal disease outbreaks are reportable to the Tennessee Department of Agriculture at (615) 837-5120. Canine flu is not reportable, but all animal disease outbreaks are reportable to the Tennessee Department of Agriculture at (615) 837-5120. https://www.tn.gov/assets/entities/agriculture/attachments/canine_influenza_veterinarians_final.pdf
Canine Influenza FAQ Instructions for diagnostic PCR swab collection General information on disease outbreak management https://vetmed-maddie.sites.medinfo.ufl.edu/files/2017/05/h3n2-civ-faqs-for-shelters-and-rescue-groups_.pdf
Questions? Staci Cannon, DVM, MPH, DACVPM, DABVP (Shelter Medicine Practice) Metro Animal Care and Control, Nashville, TN Staci.Cannon@nashville.gov 615-862-7928