Update on Canine Influenza Outbreak

Apr 21, 2015 / General News / Practitioner Updates / Veterinary Clinical Medicine

[Chicago dog outdoors]

Illinois dog owners should minimize their dog’s exposure to other dogs, if at all possible.

Update, May 26: Researchers at the College of Veterinary Medicine explored the question of whether the canine influenza vaccines available in the United States are protective against the newly emerged strain by comparing the two viral strains at the genetic level.

Update, April 21: The College of Veterinary Medicine has postponed the annual spring Dog Wash, a fundraiser of the Omega Tau Sigma veterinary service fraternity originally scheduled for Saturday, in order to limit events where dogs congregate, which is how the canine influenza virus spreads.

The OTS Dog Wash will be rescheduled after the threat of the outbreak in Chicago has subsided. The Veterinary Teaching Hospital has procedures and policies in place (contamination suits, isolation wards, separate entrances) to prevent other patients’ exposure to CIV in the event that an infected animal needs to be hospitalized.

Update, April 17: On Thursday, April 16, clinicians at the University of Illinois Veterinary Teaching Hospital examined a patient that was later confirmed to be infection with canine influenza virus.

Because the dog’s owner alerted the veterinary staff to the possibility that the dog, which had been recently kenneled in Chicago, had the flu, clinicians conducted the examination while the patient remained in the owner’s car and wore protective biohazard clothing that was discarded before the clinicians reentered the hospital.

The owner, who lives in Urbana, Ill., has voluntarily quarantined the animal at home.

“We are prepared to follow biosecurity measures to ensure that the virus will not pose a threat to our patients,” said Dr. Laura Garrett, chief of staff at the Veterinary Teaching Hospital.

The canine influenza virus does not infect people. The majority of dogs who become infected experience mild symptoms. Infected animals that are immunocompromised, such as the very young or very old, may be susceptible to secondary infections, leading to more serious conditions, such as pneumonia.

Update, April 15: Laboratory scientists at Cornell University and the University of Wisconsin have determined that the current outbreak of canine influenza virus, which has sickened more than 1,000 dogs in the Chicago area, is caused by a virus related to Asian strains of influenza A H3N2 viruses. This strain has also caused infection and respiratory illness in cats in Asia, though no cases of cats being infected in the U.S. have been reported.

Update, March 31: Dr. Brendan McKiernan, director of the University of Illinois Veterinary Teaching Hospital in Urbana and an internationally renowned specialist in respiratory diseases of dogs and cats, advises giving the canine influenza vaccination to Chicago area dogs that will be around other dogs (at shows, boarding, dog parks, etc.), at least until this outbreak is over.

“Avoidance of exposure is the name of the game for now,” he adds. “Even if you vaccinate, the vaccines are protective only after the booster, injected three to four weeks after the initial vaccination. We also won’t know for a while whether this is the same canine influenza virus that is in the vaccine, or if it is a mutation of that virus. Lastly, remember that no vaccine can be 100 percent protective.”

Update, March 27: The canine influenza virus has been identified in at least three of the Chicago area cases, according to information from the Animal Health Diagnostic Center at Cornell University, one of the few veterinary diagnostic laboratories that offer a canine respiratory panel identifying common viruses and bacteria associated with kennel cough. Numerous Chicago area cases are still being tested, but at this early stage the outbreak appears to be typical for collections of dogs rather than indicative of a new viral strain.

Chicago area veterinary clinics, including the University of Illinois’s primary care practice, the Medical District Veterinary Clinic at Illinois, have reported seeing an increase in the number of kennel cough cases this month, and some boarding facilities have closed for disinfection to prevent further spread of this disease.

Clinically known as acute infectious tracheobronchitis, kennel cough is not unique to kennels, but rather is a contagious disease associated with any concentration of animals, such as at dog parks or shows. The disease may be caused by a host of viral culprits, including canine distemper virus, canine adenovirus, canine parainfluenza virus, and the more recent canine influenza virus.

[Dr. McKiernan examines a dog]

Dr. Brendan McKiernan, director of the University of Illinois Veterinary Teaching Hospital in Urbana, is an internationally renowned specialist in respiratory diseases of dogs and cats and the founder and first president of the Veterinary Comparative Respiratory Society.

“You can’t tell these viral agents apart clinically, since they all produce acute coughing,” says Dr. Brendan McKiernan, director of the University of Illinois Veterinary Teaching Hospital in Urbana and an internationally renowned specialist in respiratory diseases of dogs and cats. “Laboratory testing is needed in order figure out what is causing the current kennel cough outbreak in Illinois.”

Viruses are continuously mutating. Most of the time, these viral mutations pose little threat. Sometimes, however, a mutated virus emerges that causes more severe clinical signs or spreads more easily among a population.

“The canine influenza virus emerged about ten years ago after a horse virus mutated in such a way that allowed it to infect dogs. In 1978 we recognized a new deadly intestinal virus in dogs – parvovirus, which was a mutation of a corona virus that was able to infect dogs,” says Dr. McKiernan. “Whether this outbreak of respiratory disease in Chicago may be caused by a new virus remains to be seen.”

Unfortunately viral infections cannot be treated. Preventive vaccination is the best way to protect dogs from kennel cough.

“The DA2PP vaccine, which covers canine distemper, adenovirus, parainfluzena and parvovirus, is recommended for all dogs. Canine influenza can also be vaccinated for separately, which may be a good idea for animals that are frequently exposed to others, for instance at dog shows. Bordetella vaccination is recommended for any animal that will be boarded at a kennel or dog day care,” says Dr. McKiernan. “Vaccines do not completely prevent infection, but can minimize the severity of the disease.”

Depending on an animal’s health condition, the effects of kennel cough can be mild to severe. Animals that are young, are old, or have an impaired immune system are more susceptible to these infections and their consequences.

“When an animal gets a bacterial infection, such as Bordetella bronchiseptica, on top of the viral respiratory infection, the disease can progress to pneumonia,” explains Dr. McKiernan.

Several affected dog facilities in the past have been forced to close in order to disinfect their facilities.

“It is similar to the way cruise ships deal with a viral outbreak. The whole ship depopulates in order for appropriate disinfection,” says Dr. McKiernan. “When there is a patient in our hospital that may have kennel cough, we close that exam room and thoroughly clean the room to minimize exposure to the next dog that enters that room.”

Until veterinarians gain a better understanding of the cause of the current outbreak, Dr. McKiernan recommends minimizing a dog’s exposure to other dogs if at all possible. Be alert to signs of coughing, especially if the dog has been exposed to other dogs in the previous two weeks. Keep pets up to date on vaccinations, and contact the family veterinarian with any concerns.

By Melissa Giese, Class of 2017