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What to know about the mystery illness that is killing dogs in the US

Vets are recommending dog owners keep their pets away from social settings like parks and boarding facilities until more is known.
What to know about the mystery illness that is killing dogs in the US
Posted at 4:47 PM, Nov 13, 2023

Veterinarians and animal shelters in different parts of the U.S. are reporting a rise in a highly contagious and sometimes deadly respiratory illness in dogs. 

It starts with a cough. Vets said a typical case of kennel cough is characterized by the same symptoms as this unknown illness: coughing, loss of appetite, runny nose, lethargy and sometimes a low fever. But while kennel cough clears up after 7 to 10 days, this new illness lasts weeks and sometimes leads to acute, or even fatal, cases of pneumonia. 

"I would say [there's been] maybe a 50% increase in the number of coughing dogs we detect," Dr. Amanda Cavanagh at the Colorado State University Veterinary Teaching Hospital told Scripps News Denver

Cavanagh said the illness appears to be spreading in social settings like kennel cough does, such as boarding facilities and dog parks. 

In most cases, the onset of pneumonia in dogs can be treated with antibiotics. But for more severe cases, that’s not enough. 

"Some of those dogs come in with a very sudden onset of the pneumonia signs, and they are very sick. They require mechanical ventilation, so a breathing tube with a machine breathing for them," Cavanagh said. "And many of those dogs are actually passing away or being euthanized because of this really severe, fast-moving, really intense pneumonia."

In Oregon, the state Department of Agriculture has received 200 written reports from veterinarians about the mystery disease. According to the Oregon Veterinary Medical Association, cases first started popping up around August. 

In some reports, the infected dogs have died within just a couple of days after developing pneumonia.  

SEE MORE: Family lives in 'daily dread' after dog dies from mystery illness

“Unfortunately, very few of those dogs have received a full necropsy to determine the cause of death,” a spokesperson for the department, Andrea Cantu-Schomus, said in an emailed statement to Oregon Public Broadcasting (OPB). 

She noted some of the deaths that have been studied showed underlying conditions in the dogs that combined with the illness. 

Pathologists and virologists from state and federal veterinary laboratories as well as the Oregon Veterinary Diagnostic Laboratory at Oregon State University are working with the department to figure out where this illness is coming from, OPB said

Further southwest, the San Diego Humane Society and The Animal Foundation in Las Vegas are calling it streptococcus zooepidemicus, or “strep zoo.”The Animal Foundation first reported a rise in infections at the end of October. Since then, at least three infected dogs in the shelter died, and another three were “humanely euthanized,” the nonprofit said on its website. 

The San Diego Humane Society has temporarily stopped taking in dogs surrendered by their owners until December because of the growing number of respiratory infections. 

While experts work to learn more about the disease, it’s important to keep a close eye on your pets for symptoms. Persistent coughing, appetite changes and differences in their energy levels are signs to look out for, vets said. 

Vets also said it’s safer to keep your dogs away from the parks and other social settings until cases start to decrease. 

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