Canine Respiratory Outbreak

Respiratory Syndrome of Unknown Etiology in Dogs 2022-3 in New England: Diagnostic Investigation   


Most Current Update Jan 25, 2024 Click Here


Previous Updates Below

This is a respiratory syndrome, which means that there is a group of animals with similar clinical signs - in this case upper respiratory disease that is resistant to standard treatments and does not result in positive tests for common respiratory pathogens.   There are a variety of typical canine respiratory pathogens which veterinarians are routinely able to diagnose and treat in dogs.   The cases we are investigating have already tested negative at laboratories for usual pathogens.  The purpose of this investigation is to determine the possibility of any emerging pathogens not known to cause respiratory disease.   Please note that there has been no official identification of what causes this syndrome.  Any of these findings are preliminary, and ongoing investigation will be necessary to make any final determinations.

Clinical Signs: Clinically the cases present similarly to other canine respiratory diseases such as kennel cough.  They seem to be refractory to standard medical treatment and are usually negative on syndromic canine respiratory disease PCR testing. Cases commonly have a long course of illness, with some progression to pneumonia. In NH there have been anecdotal reports of mortalities, however submissions of carcasses or excised lung tissue have been minimal.

Timeline: The initial part of our investigation began in the late summer and autumn of 2022 in NH. In response to anecdotal reports of a respiratory syndrome as described above, the New Hampshire Veterinary Diagnostic Lab (NHVDL) and Hubbard Center for Genomic Studies (HCGS), both located at the University of New Hampshire, began analyzing respiratory specimens from these NH cases employing state-of-the-art metagenomic techniques. In 2023 samples were also tested from southeastern MA and northern RI who were also reporting increased cases of syndromic cases.  In June 2023  preliminary findings were disseminated to NH Veterinarians and also shared with our fellow New England states where similar reports of infection were occuring.  

We currently have more samples in hand that arrived late last week from Oregon, and anticipate more next week from Colorado, and then later from Illinois and other states, so we can ascertain if the findings we have in our region are similar to those. 

Preliminary Findings:  

Known canine respiratory pathogens were not identified.  This early metagenomic work did not reveal any RNA or DNA virus of concern, and no typical fungal or bacterial respiratory pathogens were identified. 

The sequence data has revealed a non-culturable, bacterial-like organism, similar to Mycoplasma in a subset of the respiratory samples.  With any investigation of this nature it is difficult to differentiate correlation and causation with the detection of DNA sequences and agents.  Canine respiratory tissues from the NHVDL necropsy biobank archive from 2018 (presumably prior to current outbreak) were tested as negative and temporal controls.   These older negative control samples have tested negative thus far for this organism.   

These findings are only preliminary.  More testing and analysis is needed before this syndrome is connected to a specific cause.   For additional information please see the FAQs below.


Frequently Asked Questions

What do I do if my dog is sick with respiratory signs?  

We encourage you to continue working with your veterinarian for management of your pet's health care, as they have an established patient client relationship and are best suited to care for your pet. 

Has the lab tested the K-9 samples for COVID-19/Coronavirus? 

Yes, samples from this investigation were tested for COVID-19 and were NEGATIVE. 

Can other animals including people be affected by this K-9 Respiratory Syndrome?  

Evidence at this point suggests that this infection has been limited to dogs 

Are particular breeds more susceptible? 

There does not seem to be a breed predilection, but we are still analyzing the epidemiological data to see if this can be determined 

How can I find out current information on this syndrome?  

We will do our best to keep the NHVDL website updated with the most current information we have available.  

What is the timeline for the study?  

We began sample collection 10/22 from NH alone. Work at the genomics center started at the end of 2022 and continues. In June 2023 we released a preliminary letter to the regional veterinary community with some findings to date. In late summer 2023 we received samples from RI and MA. We anticipate findings from Oregon, Colorado, Illinois, and other sites over the next month or so.  

I am a veterinarian and would like to donate samples to the K-9 Respiratory Study, what do I do?  

If a clinic is in an area of increased respiratory disease in dogs and would like to contribute samples, they should contact David Needle directly at  

I am a dog owner and would like to donate my dog’s records. What do I do? 

We are not collecting medical histories from owners. We work directly with veterinary clinics who would forward any appropriate records. 

What can I do to protect my dog? 

It is early in our investigation, and it is not yet certain that what we have identified is a pathogen in these cases. If it is this bacterium or something else, the preventative measures are the same for any respiratory infection. 

  • Avoid contact with other dogs 

  • Ensure your dog is up-to-date on all vaccinations recommended by your veterinarian 

  • Contact your veterinarian if your dog has clinical signs. 

No specific preventative measures or treatments are known now, and the likely timeline of development / understanding of these is long, so the above measures are the best choice.  

How can I donate to support the K-9 Investigative study?  

To help defray the high costs of DNA sequencing and bioinformatics for this level of investigation, tax deductable donations can be made to our Disease Investigation Fund. This fund helps support investigation and diagnostics for cases and events that may otherwise not have adequate funding. 

To donate online: 
Giving | New Hampshire Veterinary Diagnostic Laboratory | New Hampshire Veterinary Diagnostic Laboratory ( 

Please find the specific area for “disease investigation fund” 

To donate by mail: 
Checks should be made payable to the UNH (University of New Hampshire) Foundation and write “disease investigations fund” in the memo. Checks can be mailed to:  

UNH Foundation  
15 Strafford Avenue 
Durham, NH 03824