LSU Vet Med raises awareness about about Atypical Canine Infectious Respiratory Disease Complex (aCIRDC): Symptoms, Research, and Precautions

Clinical Signs

Clinical signs fall into three clinical syndromes:

• Chronic mild-moderate tracheobronchitis (airway inflammation) with a prolonged duration of 6 to 8 weeks or longer. Signs include coughing, sneezing, and serous or mucoid oculonasal discharge.
• Chronic pneumonia minimally responsive to antimicrobials. Signs may include dyspnea (respiratory distress), systemic signs in some patients.
• Acute pneumonia that rapidly becomes severe and may lead to death in 24 to 36 hours.
• The latter manifestation is rare. 

Pathogenesis (how a disease originates and develops)

• There is no known single causal pathogen.
• Work done by Dr. David Needle and team at the University of New Hampshire’s Hubbard Center for Genome Research suggests that a nonculturable, novel bacterium with no cell wall, tentatively named IOLA KY405 with similarities to Mycoplasma, is incriminated; it is phylogenetically distinct from most well-characterized bacteria in people and dogs.

• This conclusion has been reached by deep sequencing of 21 of 31 samples submitted to date. 

• Dr. Needle and team have been studying samples from Oregon, New Hampshire, Massachusetts, and Rhode Island; are due to analyze samples from Colorado and Illinois shortly.

• There is currently no evidence of zoonotic potential (no evidence it can be spread from animals to people).

Screening for pathogens causing CIRDC (“kennel cough”)

• Syndromic respiratory PCR panels are available to rule out known respiratory pathogens causing CIRDC, including one by LSU Diagnostics (LADDL):
  • Canine adenovirus-2
  • Canine distemper virus
  • Canine herpesvirus-1
  • Canine influenza A virus
  • Canine parainfluenza
  • Canine pneumovirus
  • Canine respiratory coronavirus
  • SARS-CoV-2
  • Bordetella bronchiseptica
  • Streptococcus equi subsp. zooepidemicus
  • Mycoplasma cynos
  • Mycoplasma canis
• LSU Diagnostics can identify three main canine influenza virus subtypes: H1N1, H3N8, H3N2
• Nasopharyngeal and nasal swabs should be taken within three to four days of signs first being observed, in the acute phase of disease.
• Specimen collection swabs and transport medium can be overnight shipped to veterinary clinics.
• Turnaround time at LSU Diagnostics is 24-48 hours.
• The remaining sample after the 12-pathogen PCR panel has been run can be sequenced, with a turnaround time of 3 to 5 days, in an endeavor to identify incriminated pathogen(s). 

Treatment

• Treatment is supportive and symptomatic, potentially including:
  • Cough suppressants if the cough is dry and unproductive;
  • Saline nebulization, so long as it does not exacerbate the cough;
  • Oxygen therapy, and in severe cases ventilation;
  • Antimicrobials if there is evidence of secondary bacterial infection;
  • Fluid and nutritional therapy.
• There is no response to typical antimicrobials used in respiratory infections; indiscriminate administration of antimicrobials is strongly discouraged.
• General guidelines are predicated on duration of clinical signs:
  • <10 days and no evidence of pneumonia: No specific treatment. Treat for seven to 10 days.
  • >10 days and fever, lethargy, inappetence, plus mucopurulent discharge: Consider doxycycline or (less desirable) amoxicillin-clavulanate.
• If there is evidence of pneumonia with systemic signs:
  • Enrofloxacin alone or in combination with ampicillin or clindamycin.
  • Re-evaluate in seven to 14 days; total duration of treatment may extend to 4 to 6 weeks, with a transition to oral therapy as soon as possible. 

Prevention

• Prevention involves avoidance of exposure, which is thought to be via infected saliva or sputum droplets.
• The risk of exposure is increased in dog daycare centers, parks, shelters, and boarding or training facilities where dogs socialize, etc.
• Being current on routine vaccination, including DA2P and Bordetella bronchiseptica, is recommended.
• Vaccination against canine influenza virus is appropriate for pet dogs or those in custody for prolonged periods; two doses and at least four weeks are required to develop immunity.
• Sanitization of all common areas, fomites, and contaminated items with accelerated hydrogen peroxide or calcium hypochlorite is recommended.  
• Standard isolation and quarantine measures for symptomatic dogs, using Personal Protective Equipment, will minimize exposure to unaffected dogs. 

Travel

The holidays are a time of year for travel, so please take precautions.

• Don't put your dog into a new population of dogs if you can help it.
• Make sure your dog is properly vaccinated before it goes into a population of dogs (e.g., dog park, boarding facility, etc.).
• Take special care when considering whether you need to bring your dog to another state and board it.
• If you're traveling with your dog over the holidays and are considering boarding facilities, ensure that the facility has vaccine requirements and a plan for handling sick animals.

News

WAFB: Mysterious dog illness: What is it and how to protect your pup - December 11 and 12, 2023

WBRZ-TV: Veterinarians cautioning dog owners about respiratory illness seen across US - December 4, 2023

USA Today: What is the mysterious respiratory illness affecting dogs across the US? Graphics explain: December 5, 2023