The Colorado Department of Agriculture (CDA) and the Colorado Department of Public Health and Environment (CDPHE) would like to share important updates regarding avian influenza infections in Colorado cats.
Highly Pathogenic Avian Influenza (HPAI) Infections in Domestic Cats
Fourteen cases of Influenza A (HPAI H5N1) have been diagnosed in felines in Colorado since May 2024. Ten of these cases were in domestic cats, while four cases were in exotic big cats. Information detailing routes of exposure for affected cats can be found in CDPHE’s current guidance document for veterinarians. A complete list of U.S. mammal HPAI detections can be found on USDA’s website. Two of the most recent cases in domestic cats were indoor only cats that had exposure to raw poultry meat (chicken, turkey). While most confirmed cases in domestic cats have resulted in death, one cat in Colorado has survived the acute illness. A history of raw pet food consumption in this case prompted H5N1 testing in this cat.
Samples of the commercial raw diet fed to the surviving domestic cat have been tested and confirmed to be positive for HPAI virus through PCR testing. Virus isolation testing is still pending to confirm virus viability, and the FDA is working to investigate the source. To mitigate HPAI exposure to companion animals, CDA and CDPHE recommend against feeding raw poultry products, especially to cats, and emphasize the need for caution when handling any raw poultry.
In cats, the clinical course has typically followed a similar pattern: initial non-specific symptoms of lethargy and inappetence, fever, sometimes followed by respiratory signs, and nearly always culminating in progressive neurologic signs and death.
Several of the feline cases were tested for rabies preceding diagnosis with H5N1 infection due to the indistinguishable presentation once neurologic signs presented. HPAI H5N1 infection should be considered in domestic felines even if all of the risk factors or clinical signs are not present.
While HPAI has been identified in several wild canids, the current risk to domestic dogs is unknown at this time. Globally, reported infections in dogs have been rare and dogs seem less susceptible to the virus than cats. It is still advisable to avoid feeding raw poultry products to dogs as well.
Information for Veterinarians
Comprehensive information regarding risk factors, prevention and control measures, sample collection and testing information, appropriate personal protective equipment (PPE), and staff health monitoring can be found in CDPHE’s Guidance for Veterinarians Assessing HPAI in Domestic Felines. Please review this document for full details to determine whether a case consultation is necessary.
- Veterinarians can contact CDPHE for consultation or support for suspect cases: 303-692-2700 or [email protected]
- Veterinarians can also contact the Colorado State University Veterinary Diagnostic Laboratory (CSU VDL) for testing guidance for live or moribund cats: 970-297-1281
General HPAI updates can be found on the CDA website at: ag.colorado.gov/hpai
Disease Reporting
HPAI is a reportable disease in all species and must be reported at the time of suspicion. Reporting can be done by calling our office at (303) 869-9130 or by visiting our Reportable Diseases webpage and filling out a Reportable Disease Form.
Please note, if you report a suspected HPAI feline case to CDPHE, they will share that information with our office. HPAI in poultry, dairy cattle, or other livestock species must be reported directly to our office.
Reporting at the time of suspicion for diseases like HPAI is critical to initiate important tracing and monitoring activities in both humans and animals. CDA and CDPHE will coordinate with the reporting veterinarian and the laboratory to ensure that we have expedited diagnostics completed. A delay in reporting can lead to a delay in necessary response measures which can compromise human and animal health.
