Michele Wright, DVM
Practice to Practice, Peer to Peer
Welcome to Today’s Veterinary Practice’s newest column—Practice to Practice. This column allows veterinary clinics to share their personal experiences with our readers—their peers. We’ll bring you stories about how clinical medicine and practice development concepts became a reality for veterinary team members and their patients and clients. Whether you’re inspired, cautioned, or educated by these narratives, our goal is to create a column that brings practices together, one tale at a time.
I grew up as the daughter of two great veterinarians who helped me realize that as a medical professional, we cannot heal all disease. Sometimes, the outcome is predetermined, not a reflection of our passion, knowledge, and skills.
However, we can prevent many infectious diseases by understanding how diseases are transmitted and through the advancement of vaccines.
Following my parents’ footsteps, I applied to veterinary school with the goal of educating pet owners on why preventive medicine is the best medicine. I wanted to be a proactive doctor; one that protected pets from diseases, such as parvovirus and distemper, rather than hope patients are fortunate enough not to be affected by serious disease.
The Infection Begins
In the fall of 2011, I worked as the relief veterinarian at my mother’s clinic. Two dogs that had been boarded at the clinic a few days earlier were coughing. They exhibited classic “kennel cough” clinical signs: mild green/yellow ocular and nasal discharge, hacking cough, mild lethargy, and a slight fever. The owner was upset because her dogs were vaccinated against Bordetella. “Why do they have kennel cough?” she asked. My husband, Dr. Travis Wright, took a nasopharyngeal swab from each dog for an upper respiratory polymerase chain reaction (PCR) panel (Canine Respiratory Disease RealPCR Panel, IDEXX.com).
Over the next few days, every dog that boarded during the same time as the first two dogs was coughing. Even our clinic blood donor dog had a high fever and was showing signs of pneumonia. When the PCR panel results came back, we finally had an answer regarding the cause of these signs—the dogs tested positive for H3N8 (canine influenza virus; CIV).
Not Just the Clinic Kennel
The virus was spreading like wildfire. Another dog that had boarded with the original two infected dogs had returned to a kennel with more than 75 dogs. The kennel called to say that some of their dogs were coughing. I had to be the one to tell them we suspected there was an outbreak of CIV and that we had not been vaccinating dogs prior to admission to our facility.
My husband and I went to the kennel to suit up and start checking every dog for clinical signs and fever. The kennel is made up of five wards, about 50 to 100 feet apart. We started with the least symptomatic ward and worked our way through each one. We walked through bleach baths, changed our gloves between dogs, and changed our protective gear between wards.
We tested random dogs that had fevers or were coughing from each ward with nasopharyngeal swabs and blood samples to send to the laboratory.
And the Outbreak Continues
Back at the clinic, all coughing dogs were seen in the parking lot with foot covers, plastic gowns, and gloves to prevent us from becoming fomites. Several dogs that were seen for an ear flush or examination the same day the two infected dogs came into the clinic returned to us with coughs.
We collected samples and sent them to IDEXX Laboratories and University of Cornell, where serology was performed on the blood and PCR on the nasopharyngeal swabs. The titers were high enough on the serology tests to confirm CIV without needing to submit a second sample.
How to “Clean” the Clinic
CIV can be killed with dilute bleach and dies in the environment in about 48 hours. The first step in bringing the outbreak under control was to close the boarding facility and only see critically ill patients for 48 hours. During this time, the entire staff, including myself, suited up and started bleaching every surface.
It was 106°F outside and we had to bleach every cage and carrier outside wearing uncomfortable, hot plastic disposable suits. It was a miserable experience for all. We disposed of every item that was not washable and even made sure to bleach the top of the cabinets. But by the end of the 48-hour period, the clinic was decontaminated and we were ready to reopen our doors.
Defining Proactive
After the outbreak, I realized I needed to be much more proactive. So what makes us proactive practitioners instead of reactive? It’s testing, vaccinating, and educating both our staff and our clients about diseases. We cannot be complacent; even if clinical signs look like kennel cough, clinics should still test for other upper respiratory diseases, such as CIV. Testing tells us what diseases are affecting our patients and then we can gauge how to best treat them as well as protect them in the future.
Vaccination: Controlling the Disease
The good news is that vaccines do exist that help control the severity and spread of CIV (Nobivac Canine Flu H3N8, merck.com; Vanguard CIV, pfizer.com). In our case, we now use Nobivac Canine Flu H3N8 to protect our patients from contracting CIV as well as to prevent severe infection.
Some practitioners shy away from vaccinating for CIV because the vaccine is not 100% effective. However, no vaccine is 100% effective. The vaccine for feline leukemia virus is only 80% effective—does that keep you from administering it?
By vaccinating for CIV, you decrease the severity and duration of the disease, which, in turn, lessens the impact of the infection on the patient; the vaccine also helps prevent shedding of the disease, which protects other dogs that are naïve to CIV. For other veterinarians who say their patients aren’t at risk, my response is that I have seen the virus travel 50 to 100 feet in the air. Dogs that came to the clinic for an ear infection and never had face-to-face contact with the originally infected dogs contracted this highly contagious virus.
Take it from me—it’s far easier to help prevent canine influenza than it is to deal with an outbreak.
Canine Influenza Overview
CIV is an emerging infectious disease that has been confirmed in dogs across 38 states and the District of Columbia.1 It’s prevalence is rising and virtually every naïve dog exposed to the virus will become infected.2 This highly contagious disease is rapidly spread by a combination of aerosols, droplets, and direct contact with respiratory secretions or contaminated fomites.2,3
Diagnosis
Clinical signs of CIV are usually seen 5 days after infection.4 See Clinical Signs of Canine Influenza Virus for a list of signs. However, CIV cannot be distinguished from other causes of acute respiratory disease based on clinical signs alone.5,6 Diagnostic testing options include flu-antigen enzyme-linked immunosorbent assay (ELISA), serology, PCR, and virus isolation. Accurate results are affected by timing of sample collection with regard to the phase of disease; therefore, use of more than one diagnostic approach may be needed to determine etiology rapidly and accurately.2
Treatment
Because there is no specific treatment for CIV, the focus of management is providing supportive care while the infection runs its course.2 In some cases, a secondary bacterial infection may be present, which indicates the use of antibiotics.2,5,7 In dogs with severe illness, critical care, such as IV fluids and supplemental oxygen, may be needed. At this time, treatment with antiviral agents is not recommended for dogs.2,7
Prevention
Effective vaccination is the best prevention against viral disease.8 Vaccines are available for CIV, including Nobivac Canine Flu H3N8 (merck.com) and Vanguard CIV (Pfizer.com). The vaccines protect dogs against CIV infection by:
- Significantly decreasing clinical signs
- Reducing viral shedding
- Reducing CIV-induced lung consolidation.
The initial CIV vaccine is given in two doses, two (Nobivac Canine Flu H3N8) and three (Vanguard CIV) weeks apart; annual vaccination with one dose is then recommended.
For additional information on canine influenza, visit the following links:
- doginfluenza.com
- cdc.gov/flu/canine
- avma.org/public_health/influenza/canine_guideslines.asp
- vetmed.wsu.edu/depts_waddl/dx/K9Influenza.aspx
CIV = canine influenza virus; ELISA = enzyme-linked immunosorbent assay; PCR = polymerase chain reaction
References
- Syndromic surveillance data of Cynda Crawford, DVM, PhD, University of Florida; Edward Dubovi, PhD, Cornell University; Sanjay Kapil, DVM, PhD, ACVIM, Oklahoma State University; Rhode Island State Veterinarian’s office; and IDEXX Laboratories; September 2011.
- Crawford C, Spindel M. Canine influenza. In Miller L, Hurley K (eds): Infectious Disease Management in Animal Shelters. Ames, IA: Wiley-Blackwell, 2009, pp 173-180.
- Tellier R. Review of aerosol transmission of influenza A virus. Emerg Infect Dis 2006; 12:1657-1662.
- Dubovi EJ, Njaa BL. Canine influenza. Vet Clin North Am Small Anim Pract 2008; 38(4):827-835.
- Canine influenza update. UC Davis Koret Shelter Medicine Program website; sheltermedicine.com/shelter-health-portal/information-sheets/canine-influenza.
- Information sheet: Canine infectious tracheobronchitis. UC Davis Koret Shelter Medicine Program website; sheltermedicine.com/shelter-health-portal/information-sheets/canine-infectious-respiratory-disease-complex-aka-kennel-co.
- Beeler E. Influenza in dogs and cats. Vet Clin North Am Small Anim Pract 2009; 39:251-264.
- Control of canine influenza in dogs-questions, answers, and interim guidelines. AVMA website; avma.org/public_health/influenza/canine_guidelines.asp.
Michele Wright, DVM, practices at Huebner Oaks Veterinary Hospital in San Antonio, Texas. She received her DVM from Texas A&M University after receiving her Bachelor’s degree in Biomedical Science from the same institution. Dr. Wright is the daughter of two veterinarians and is married to an equine veterinarian, Dr. Travis Wright. She and her husband share a love for horses as well as for their two cats, Jasmine and Ariel, and Beamer the dog.