H5N1 is different than other new swine disease outbreaks because USDA has jurisdiction over H5 in any animal, so they have the regulatory authority, says Scanlon Daniels, DVM.

Nearly one year ago, USDA made a shocking announcement. Highly pathogenic avian influenza type A H5N1 (H5N1) was identified in milk and in cows on two dairy farms in Texas and two dairy farms in Kansas. A disease no veterinarian had previously feared in cattle had jumped from wild birds to domestic cows.

Scanlon Daniels, a large animal veterinarian with Circle H Headquarters in Dalhart, Texas, received a call 10 days prior to that announcement that he will never forget from one of his dairy clients that something wasn’t right with some of the cows.

“My client sent me a text: ‘I think I might have it,’” Daniels says.

He went out to the dairy, collected samples from four cows and submitted them to Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) as any good swine vet would do, he explained, during the American Association of Swine Veterinarians annual meeting. He also took some nasal swabs and tested those in his own lab. He did a follow-up, collecting samples from 20 different cows later on that week and sent those to the Iowa State University Veterinary Diagnostic Lab.

The four cows that initially presented symptoms of decreased rumination, decreased activity and nasal discharge were eventually confirmed to have H5N1. Right around that same time, he said there were reports from Texas Animal Health Commission about a backyard poultry flock in the county next door diagnosed with H5N1.

“We had a suspicion that it could have been influenza, because of what was going on with some of the detections in birds in that area,” Daniels says. “But from my standpoint, I was thinking about flu from all my experiences dealing with it in pigs, and it didn’t present as a primary respiratory pathogen. It presented as a mastitis pathogen. Once we knew to look for it in milk, it was super easy to find, but we had to get over that hurdle to be able to rapidly identify it.”

In the past 15 years, Daniels grew his practice to develop its own laboratory capabilities, conducting PCR and Elisa testing for swine, dairy and beef clients. This, combined with his involvement with H5N1 from before it was even identified as an issue in cattle, caused him to bring up an incredibly important question for the swine industry: Are you ready for H5N1?

Who is Steering the Ship?
To date, H5N1 has been discovered in one pig that was on a hobby farm with H5N1-infected poultry. Although this is considered an isolated incident and hasn’t been discovered in the commercial swine population, it needs to be on everyone’s radar, Daniels says.

Andrew Bowman, DVM, one of the country’s top swine influenza experts, joined The PORK Podcast during a special report on H5N1 last fall. A professor in the Department of Veterinary Preventive Medicine at The Ohio State University, he is well-known for his expertise in swine production medicine, veterinary public health and epidemiology.

“Across the swine industry, we routinely deal with influenza, so we’re pretty well versed in flu,” Bowman says. “But this adds a whole other character to the scene that we really don’t want reassorting with the flu viruses we already have.”

One of the things that makes H5N1 different than other new swine disease outbreaks is that the USDA has jurisdiction over H5 in any animal, so they have the regulatory authority, Daniels says.

“USDA had no rules or regulations around H5 in cattle, and we’re at the same place today in the swine industry,” Daniels adds. “If we were to find H5 in swine, USDA would have the authority and there are no rules or regulations around it.”

This has made the discovery of H5N1 in dairy cattle challenging in the past year, because it’s taken a long time for those regulations to be developed.

“There’s the state and federal aspect of that, where states have autonomy to set their own rules, and then federal rules can come in place that everybody has to abide by,” he points out. “There’s been this slowly evolving plan with a patchwork of regulations by different states. That’s been challenging to keep up with as a veterinarian and a producer.”

The recent COVID-19 pandemic has likely amplified concerns around influenza’s ability to be transmitted from humans to animals and from animals to humans.

“No one wanted to be first or second or third to get H5N1 in their dairy cattle – just like no one wanted to be first to get COVID-19. There was a reluctance to test because of the uncertainty of it,” Daniels explains. “People fear government overreach or regulations that wouldn’t be applied in a fair or equal way across the industry.”

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