A perplexing respiratory illness is spreading among dogs throughout the United States, raising alarm among veterinarians. The exact scale of the outbreak, including the number of affected dogs and fatalities, remains unknown, posing challenges to tracking and managing the situation.
The American Veterinary Medical Association (AVMA) issued a statement on December 6, shedding light on the enigmatic canine respiratory infection. The lack of a national data tracking system for canine illnesses complicates efforts to gauge the full extent of the issue. Nevertheless, the AVMA confirmed the presence of the illness in at least 14 states, with Colorado, Oregon, and New Hampshire leading the way in laboratory testing to pinpoint the cause.
Veterinarians in critical care settings have anecdotally reported dozens of cases since the fall. The illness typically manifests as a persistent cough, lasting weeks to months, unresponsive to conventional treatments like antibiotics or antivirals. In severe instances, the cough evolves into pneumonia, with fatal consequences if the dog struggles to obtain sufficient oxygen.
Multiple warnings about the mysterious illness have been issued since early November, with the Colorado and Oregon departments of agriculture and the AVMA all highlighting the urgency of the situation. Dr. Lindsey Ganzer, CEO at North Springs Veterinary Referral Center in Colorado Springs, attests to the swift progression of the illness, noting its rapid shift from a persistent cough to life-threatening pneumonia.
Dr. Gina Kettig from VCA Alameda East Veterinary Hospital in Denver reports a surge in infections, emphasizing the utilization of isolation wards due to the severity of cases. Dr. Ganzer, who has seen over 30 cases since October, emphasizes that the illness appears to affect dogs of all ages, sizes, and breeds, with a higher incidence in those recently exposed to group settings like kennels or doggy day care.
Concerns are mounting, with veterinarians urging dog owners to avoid boarding facilities, groomers, and other places where dogs congregate. The AVMA advises dog owners not to panic if their dog develops a cough but to remain vigilant and seek veterinary attention promptly if any concerning symptoms arise.
The mystery illness presents with symptoms such as coughing, sneezing, eye or nose discharge, abnormal fatigue, and an absence of positive tests for common canine respiratory illnesses. The Oregon Department of Agriculture notes that affected dogs may exhibit coughs lasting for weeks to months, defying conventional treatments.
Notably, the distinguishing feature of this outbreak is the elevated incidence of dogs developing pneumonia. Dr. Michael Lappin, director of the Center for Companion Animal Studies at the Colorado State University School of Veterinary Medicine, highlights a 50% increase in canine pneumonia cases in Colorado between September and November 2023 compared to the previous year.
Pet insurance company Trupanion reports a rise in claims for dogs with respiratory illness in multiple states. Dogs are most likely contracting the mystery illness in settings with close contact among numerous dogs, such as day care, dog parks, groomers, or boarding kennels.
Between mid-August and mid-November, the Oregon Department of Agriculture received over 200 reports of the illness, and the Colorado Department of Agriculture notes double the usual number of cases reported by veterinarians in the state. Dr. Amanda Cavanagh from Colorado State University James L. Voss Veterinary Teaching Hospital observes a doubling of cases with coughs lasting several weeks or longer.
While the exact number of fatalities is unknown due to the lack of comprehensive tracking, confirmations of deaths attributed to the mystery illness have been reported. The Colorado Department of Agriculture acknowledges “some fatalities,” emphasizing the rapid progression from pneumonia to death in rare cases.
The origin of the rising respiratory illness in dogs remains unclear. Dr. Lindsey Ganzer notes that her hospital has been sending samples to the University of New Hampshire’s Veterinary Diagnosis Laboratory, which has been studying the illness since 2022. Researchers have identified a bacterium that may be linked to the surge but emphasize the need for further testing for confirmation.
Dr. Scott Weese, a pathobiology professor at the University of Guelph Ontario Veterinary College, suggests that the disease patterns do not align with the emergence of a new highly transmissible pathogen. He acknowledges the concern for a new pathogen but notes that unusual cases often involve known pathogens behaving differently.
Other potential factors contributing to the surge include the possibility of multiple infections, lowered immunity due to pandemic-era restrictions on boarding and day care, and declining vaccination rates in dogs.
Cases matching the description of the mystery dog illness have been reported in multiple states, including Oregon, Colorado, California, Illinois, Florida, Georgia, Indiana, Massachusetts, Washington, Vermont, Maryland, Idaho, New Hampshire, and Rhode Island.
In response to the outbreak, veterinarians advise dog owners to closely monitor their pets for symptoms, seek prompt veterinary attention for persistent coughs, and avoid group settings where dogs may come into close contact. Maintaining up-to-date vaccinations, including Bordetella, Adenovirus type 2, and parainfluenza combined with the injectable influenza H3N2 vaccine, is recommended to support overall canine health.
While the likelihood of humans contracting the respiratory illness is low, thorough handwashing is advised after handling any dogs, especially those exhibiting symptoms. Veterinarians suggest submitting samples to research labs if a dog is diagnosed with the mystery coughing illness to contribute to efforts in identifying the cause.
