H5N1 avian flu, a virus, has hit all of the outbreak areas, but many of the mystery infections appear to be bacterial
SPOKANE, Washington; SAN DIEGO, California; LONDON, U.K.; LIMA, Peru––Fall is the flu season, for humans and animals.
Therefore, just because mysterious new flu-like diseases in dogs, cats, and marine mammals are appearing coincidental with global outbreaks of H5N1 high pathogenic avian influenza among birds, mostly spread by migratory waterfowl and sometimes by cockfighters, does not mean there is any connection between bird flu and the other outbreaks of respiratory disease among widely disparate species.
Viral, bacterial, or?
Until the mysterious new flu-like diseases are adequately identified, though, the possibility of a relationship is not easily refuted.
For instance, while H5N1 is a virus, even a mildly experienced viral illness can potentially open pathways for a bacterial disease to strike a susceptible animal.
Usually the most successful response to a virus is a vaccine, but developing vaccines is a relatively slow process compared to the speed with which viruses can mutate, especially when millions of animals of hundreds of species may be hosting different strains of a virus, enabling them to mix and mingle.
Usually the most successful response to a bacterial infection is an antibiotic, but ever-increasing numbers of bacteria have become antibiotic resistant.
Traditionally, if an antibiotic stops a disease, a mysterious pathogen is presumed to be bacterial, but if antibiotics fail, that no longer means the pathogen must be viral.
“Not enough data to panic”
“As fears over respiratory illness in dogs spread, Washington state vet says there isn’t enough data to panic,” headlined Alexandra Duggan of the Spokane Spokesman Review on November 24, 2023.
Wrote Duggan, “Officials are on alert about a mystery respiratory illness killing dogs, but they haven’t found proof or noticed trends that it’s spreading in Washington,” despite reports that it has already hit dogs, especially dogs in animal shelters, in California, Colorado, Florida, Georgia, Idaho, Illinois, Indiana, Massachusetts, New Hampshire, Oregon, Rhode Island, and of course Washington.
Explained Duggan, “Washington State Veterinarian Amber Itle, VMD, who works at the Department of Agriculture, said state laboratories are tracking trends of diseases in animals. Just like humans, it’s also common for dogs to get respiratory diseases, viruses, bacterial infections or a strong cough that can usually be resolved with treatment or time, she said.”
Not enough data to show it’s new, either
Said Itle herself, “We don’t have enough data to show we have something new.”
Neither is it even clear that the mystery respiratory illnesses killing dogs around the U.S. are all the same disease, from the same source.
But the stories emerging from animal shelters across the country do tend to sound much the same.
“SpokAnimal, an animal shelter in Spokane, began quarantining their dogs five weeks ago because they saw an illness that looked like kennel cough, but turned into pneumonia. It wasn’t something the shelter had seen before,” Duggan mentioned.
“The sickness came with coughing, lethargy, lack of eating and a runny nose,” Duggan recounted. All are familiar symptoms, but none are definitive of any one specific disease.
“It should worry people”
“One of their dogs died, so they sent the body to Washington State University for testing,” Duggan added. “Certain tests came back negative, so ‘Nobody knows what it is just yet,’” SpokAnimal executive director Dori Peck told Duggan.
Opined Peck, “It should worry people.”
In Medford, Oregon, a 10-hour drive south via U.S. 97, the Jackson County Animal Services shelter closed to the public and halted pet adoptions at least until December 5, 2023, Jackson County Health & Human Services director Stacy Brubaker told April Ehrlich of Oregon Public Broadcasting.
Brubaker said that about a third of the shelter’s 100 dogs appeared to have respiratory illnesses.
From kennel cough to pneumonia
“Brubaker said it’s not clear which dogs might have kennel cough — a more common respiratory disease that tends to spread in shelters and boarding facilities — or a new canine respiratory illness that has recently appeared in several states,” reported Ehrlich.
“The new canine illness shares many symptoms with kennel cough: coughing, sneezing, nasal or eye discharge, rapid or labored breathing, lethargy, decreased appetite and fever,” Ehrlich detailed.
“The big difference is how quickly it seems to turn from a mild cough to severe pneumonia. In some cases, it has killed dogs within a couple of days. Researchers don’t know what causes this illness or how to treat it. The new illness doesn’t seem to respond to antibiotics that typically work for kennel cough.”
San Diego Humane Society
Another 12 hours south, via U.S. Interstate Highway I-5, San Diego Humane Society veterinarian Laura Bunke reported contending with “an outbreak of the bacteria known as strep zoo, along with another bacterial infection that has made the disease more severe than it usually is,” while operating at 150% of rated kennel capacity.
But Bunke told media that the San Diego Humane Society had not seen any unusual outbreaks.
“We did send out more testing than we normally would because of the more severe signs,” Bunke said, “but every test we have sent out has tested positive for something known.”
Acute awareness of “A mysterious and potentially fatal respiratory illness in dogs” spread nationwide after a November 16, 2023 report by Maura Hohman of Today mentioned that it “starts out as a cough that can last for several weeks, but it may not respond to typical treatment, such as antibiotics, which can leave the dog struggling to breathe and with severe pneumonia.”
“Bacterium smaller than normal”
Continued Hohman, “Dogs with this mystery illness usually have coughing, sneezing, eye or nose discharge, are abnormally tired, and do not test positive for any common causes of respiratory illness, the Oregon Department of Agriculture noted in a November 9, 2023 press release.
The Colorado Department of Agriculture also issued an advisory about the mystery illness.
The Veterinary Diagnosis Laboratory at the University of New Hampshire’s Veterinary Diagnosis Laboratory claimed to have “identified a bacterium that could be behind the surge in respiratory illness in dogs,” Hohman summarized, “but more testing is needed to confirm.”
Explained Hohman, “The bacterium is smaller than normal bacteria and hasn’t been known to cause disease before, Dr. David Needle, pathology section chief at the College of Life Sciences and Agriculture at the University of New Hampshire, told NBC News.”
Strep zoo & Mycoplasma
“Smaller bacteria can sometimes cause worse illness because it’s easier for them to bypass the dog’s immune system and get into the respiratory tract and lungs, Dr. Karl Jandrey, professor at the University of California, Davis, School of Veterinary Medicine, told NBC News.”
San Diego Humane Society chief medical officer Zarah Hedge, however, told Hohman that the San Diego outbreaks and a similar outbreak in Las Vegas were identified as Strep zoo and Mycoplasma, both treatable with antibiotics.
Mycoplasma are among the most common of bacteriums, occurring in plants as well as animals, and are mostly harmless.
On the other hand, mycoplasma gallisepticum, first found in factory-farmed turkeys, is now a common and deadly bird feeder disease, loosely associated with local declines in cat predation on sick birds.
Hybrid of feline & canine coronaviruses
Meanwhile, the Telegraph of London reported on November 10, 2023, “A highly infectious and deadly coronavirus strain that has killed at least 8,000 cats in Cyprus has spread to the U.K., scientists have found.
“A cat brought to the UK from the Mediterranean island was found to be infected with the virus, sparking fears for British pets.
“The strain that led to the outbreak in Cyprus has been identified as a newly emerged hybrid of an existing feline coronavirus and a canine coronavirus,” the Telegraph said. “It is called F-CoV-23 and is not linked to COVID-19,” although it does appear to respond to treatment with drugs developed to fight COVID-19 infections.
Feline Infectious Peritonitis
“Scientists from the University of Edinburgh, the Royal Veterinary College, and the Cypriot government found the British case had the same ‘genetic fingerprint’ as 91 infected cats in Cyprus,” the Telegraph explained.
“The disease caused by the coronavirus, feline infectious peritonitis (FIP), is common around the world, including in the U.K.,” the Telegraph added. “Before the evolution of the new strain, however, the coronavirus lay dormant in cats and in most cases never caused an issue.
“Around one in 10 of the cats with the benign infection would go on to develop FIP when the virus mutated inside of them,” the Telegraph explained. “Symptoms include lethargy, fever, a swollen abdomen, and inflammation. It is almost always fatal unless treated.
“The new study found the recombination of canine and feline coronaviruses––which includes the cat virus gaining the dog pathogen’s spike protein––has led to the virus becoming more
infectious and changing how it causes disease,” the Telegraph report finished.
Migratory bird connection?
Nothing as yet seems to link F-CoV-23 to any avian disease. However, more than 150 million birds of at least 422 identified species migrate over Cyprus each spring and fall.
If some variant of H5N1 high pathogenic avian flu was to begin infecting dogs and cats, either directly causing illness or making them more vulnerable to illness, Cyprus might well be where it would happen and be noticed first.
Peruvian sea lions
Consuming the remains of infected birds is one of the most likely ways for carnivorous mammals to contract H5N1.
A scientific team led by Victor Gamarra-Toledo, Pablo I. Plaza, and Roberto Gutiérrez, (2023), in a study entitled “Mass mortality of sea lions caused by highly pathogenic avian influenza A (H5N1) virus” published by the U.S. Centers for Disease Control & Prevention periodical Emerging Infectious Diseases, in October 2023 reported their findings from “a synchronized mass mortality of over 5,000 Peruvian sea lions presenting symptoms characteristic of avian influenza A (H5N1) infection.”
They estimated that about 5% of the entire Peruvian sea lion population were killed by the virus.
52% human mortality rate
“H5N1 is a highly virulent and extremely infectious pathogen, particularly in birds,” the team warned. “First discovered and isolated in 1996 from geese in Guangdong Province, China, H5N1 has repeatedly mutated, reassorted, and spread throughout Asia, Europe, North America, and, most recently, Africa. Along with its sister strain A (H5N2), H5N1 has been responsible for over 200 million avian deaths since 2002.
“Avian influenza is panzootic, affecting not only birds but also mammals, including humans,” the team continued. “While person-to-person transmission is rare, contact with infected birds has resulted in 878 reported cases of human infections since early 2003, 458 of which were fatal, thus leading to a human mortality rate of 52%.
“The impact of H5N1 on livestock and wildlife is even more severe, with H5N1 claiming the
lives of hundreds of thousands of mice, ferrets, and pigs globally,” along with many millions of birds, both wild and domesticated, the team explained.
“Similar to zoonotic spillover events reported in New England seals in the United States,” the team added, “the sizeable infected biomass of dead marine birds may have caused H5N1 to be transmitted from birds to Peruvian sea lions, thus resulting in unprecedented mortality in the species.”