The New Canine Social Disease
By Bernadine Cruz, DVM
How embarrassing... Your kennel, doggie daycare, pet store, or grooming facility is experiencing an outbreak of a preventable canine social disease: influenza.
Your clients are upset; their pets are sneezing and coughing. Though you require all dogs to be current on their Bordetella bronchiseptica vaccine, your clients are sure it is canine cough, and it is all your fault.
What is making these pets sicker than a dog? How do you inform those clients whose pets are presently not affected but are at risk? How do you keep this from happening again?
The causative agent is likely canine influenza, H3N8. It is a new, highly contagious respiratory disease to which all dogs across the United States are susceptible. This viral ailment is not one that can spread to people or cats. Why are so many dogs being affected? Our pups are in a situation similar to the human influenza H1N1 outbreak of 2009, which was inappropriately given the moniker “swine flu.” The “at-risk” demographics are unusual.
Every year the flu strain that affects people varies. Typically we build up some immunity to this seasonal scourge as the result of exposure to similar viruses over our lifetime. H1N1 is not a new virus, but the last time it caused havoc was in 1918. If you are a history buff, you might remember learning about the Spanish flu. It caused devastating illness and death, affecting over 500 million people throughout the world. With the passing of the generation that survived that rampage went their immunity.
Our present populous was naïve to the H1N1 bug. Our dogs are also inexperienced with H3N8. Veterinarians, however, were familiar with H3N8 before 2003 but only in horses. It was in that year that the first cases of a new respiratory disease complex were seen in racing greyhound dogs in Florida. The virus had mutated from being a solely equine illness into one affecting dogs. It jumped species.
A newly recognized disease entity, Canine Infectious Respiratory Disease Complex (CIRD) actually includes canine influenza. It is virtually impossible to differentiate one virus from another respiratory ailment on the basis of clinical signs only. CIRD can consist of one or more of the following infectious agents: canine respiratory coronavirus, Bordetella bronchisecptica, Mycoplasma spp., Streptococcus zooepidemicus, distemper virus, adenovirus, parainfluenza, canine herpesvirus, and canine influenza virus.
All ages and breeds are potential victims of H3N8. The vast majority of affected pets exhibit only mild sneezing, a cough, runny nose and eyes, and variable lethargy. Occasional pneumonia and rare fatal complications can occur. Disease transmission is via nose-to-nose contact (dogs licking each other), aerosolizing of particles in nasal discharge or cough particulates, contaminated hard surfaces (cages, flooring, water bowls), hands, and clothing.
The colder the environment, the longer H3N8 can survive. At refrigerator temperatures, the virus can remain infective for more than 30 days. On clothing and skin, it can survive for a day. Cleanliness is the key to disease control, no matter the causative agent.
Complicating the diagnosis of canine influenza is the pattern of when the pet is infectious and when it demonstrates signs of illness. Once the pet is exposed to the virus, in as short as 24 hours, the pet can begin to shed copious amounts of the virus in saliva, and nasal and cough discharges. It continues to shed the canine influenza virus for about a week. A pet typically does not appear to be under the weather until it is no longer contagious, around 10 days after contraction of the ailment.
So how is a veterinarian, let alone a groomer or owner of a daycare or kennel, supposed to know what is making a dog look and sound like it has canine cough? Therein lies the problem. A doctor is not going to screen a healthy dog for virus particles. A dog ill with H3N8 is no longer shedding. Antibodies don’t show up in the body until 14 days post exposure. Antibody titers usually need to be done several times in order to confirm the presence of the disease (the cost can be prohibitive). So what to do? Support and prevent.
If you realize that a respiratory disease is affecting your canine clientele, don’t delay in informing the pet owner. At Laguna Hills Animal Hospital, we have found that being forthright and prompt in providing the news has netted the best results. The analogy of a child catching a cold at a daycare facility despite all kids being vaccinated and parents being instructed to seek alternate daycare when a child is exhibiting signs of illness causes heads to nod in an empathetic manner. If a pet appears ailing, strongly recommend the owner seek veterinary attention. As with other viral diseases, treatment is mostly supportive: rest, good nutrition, antibiotics if pneumonia is diagnosed, and other symptomatic therapies.
A vaccine to help protect dogs from H3N8, canine influenza, now exists. Unfortunately, no vaccine for animals or people is 100% protective, but it can markedly decrease the severity of the clinical signs. Recommend that your pet owners plan ahead if they are going to put their dogs in a situation where contact with this disease is likely. A dog will need an initial series of two canine influenza vaccines separated by three to four weeks before immunity can be conferred. Make your clients aware of your vaccine protocol. Adhere to it. A single sneeze can send the virus flying up to 20 feet. Speak with your local veterinarian concerning establishing a proper vaccine protocol. You can also reference the American Animal Hospital Association website (https://www.aahanet.org/Library/CanineVaccine.aspx).