A new report details how cats from at least one dairy farm in Texas have died after catching H5N1 avian flu – not from birds, but from drinking raw cow’s milk.
Only recently, the Centers for Disease Control and Prevention (CDC) reported that a dairy farm worker had tested positive for H5N1 avian flu, having caught it from the cows themselves. In fact, dozens of herds are thought to have been affected this year, underscored by the news that virus fragments have now been detected in samples of milk. That’s not a problem for us humans, as long as we’re only consuming pasteurized milk. But, in the latest sorry twist to this saga, it could be a problem for some of the farms’ feline residents.
The H5N1 strain of avian flu has been hovering in the background of conversations about potential future pandemics for many years now, but it has recently been in the headlines all the more. The World Health Organization (WHO) has called it “an enormous concern”, and has said that we’re currently in a global animal pandemic of the disease.
While it did start in birds, with very occasional jumps into humans, it’s now branched out to mammals including cetaceans and polar bears, as well as bird species you might think would be more isolated.
According to the report, illness in dairy cows was first noted in February this year in the Texas panhandle, followed by similar cases in Kansas and New Mexico. The cows themselves started eating less and producing less milk, and what they did produce had a thickened, yellowish appearance. After a few days, they mostly recovered okay.
Unfortunately, it seems some of the domestic cats living on these farms weren’t so lucky.
Cats are known to be susceptible to avian flu viruses, but they usually catch them after hunting infected birds or eating their meat. After analyzing two deceased cats sent to the Iowa State University Veterinary Diagnostic Laboratory from a Texas dairy farm, as well as milk samples from cows that had shown symptoms, experts have concluded the cats caught H5N1 after drinking milk.
Pathology showed the cats had evidence of infection in their brains, lungs, hearts, and eyes. Ars Technica reports that other affected cats displayed symptoms like discharge from their eyes and noses, loss of coordination, depressive behaviors, and blindness.
Analysis of the milk samples demonstrated the high rates of viral shedding from the infected cows. The authors state that around half of the cats that were fed raw milk later died, and the viral isolates from both cat and cow tissue samples were genetically similar, so it looks likely the milk was the source of the infection.
“Although exposure to and consumption of dead wild birds cannot be completely ruled out for the cats described in this report, the known consumption of unpasteurized milk and colostrum from infected cows and the high amount of virus nucleic acid within the milk make milk and colostrum consumption a likely route of exposure,” they write.
As to how the cows were infected in the first place, the authors suggest it’s likely their feed was contaminated with feces from infected wild birds.
If nothing else, the sad story of these cats should serve as a reminder of one of the many dangers of consuming unpasteurized milk. But more than that, it adds another thread to the emerging tapestry of H5N1’s rise across the world, and helps explain why authorities are keeping such a close eye on this virus and the risk of even more spillover events.
The study is published in Emerging Infectious Diseases.
Source Link: Bird Flu Kills Farm Cats As Highly Pathogenic H5N1 Hits Yet Another Species