Episode 216 - Highly Pathogenic Avian Influenza (HPAI) identified in Texas and Kansas dairy cattle - UMN Extension's The Moos Room
Welcome to The Moos Room, everybody. This is doctor Joe Armstrong. Special episode, unfortunate news, but it's breaking news, and it needs to be shared as quickly as possible. It's nearly 8 pm on March 25, 2024. And today, at 3 pm, USDA APHIS gave us an announcement saying that they have had cattle, dairy cattle, in Texas and Kansas test positive for highly pathogenic avian influenza.
Dr. Joe Armstrong:As of now, this is on 4 premises, 2 in Texas and 2 in Kansas, and they have tested positive for HPAI or highly pathogenic avian influenza. Now HPAI is the common abbreviation for this. High path is what people say. And when they say high path, they're talking about highly pathogenic avian influenza. So you'll hear me kinda switch things around and say those different things, but a lot of times, I'm gonna say high path or I'm gonna say influenza.
Dr. Joe Armstrong:What we're talking about for this context is HPAI, highly pathogenic avian influenza. Now high path historically infects birds, which makes sense because it's an avian influenza. It's a virus that usually infects birds, but it has been documented to infect mammals such as cats, skunks, and foxes. Now because this is an avian influenza and avian virus, it does not only just infect domesticated birds like poultry, and that's nothing new. We've been dealing with highly pathogenic avian influenza or high path in Minnesota for quite a while.
Dr. Joe Armstrong:It's plagued our poultry industry for the last couple of years, and it's a big deal. It's been a huge economic loss for the poultry industry. But part of the problem is that it also can infect wild birds. And right now, based on the findings from Texas, that's where we think the virus is coming from. The virus appears to have been introduced by wild birds on these different dairy premises.
Dr. Joe Armstrong:At this time, we're looking at more testing and more results needed to have a better understanding of what's going on. And both federal and state agencies are trying to move quick to conduct additional testing for high path and viral genome sequencing so they can better understand what's going on. Right out of the gate, I think one of the most important conversations we can have about this situation is that, at this time, information from USDA, FDA, and CDC indicates that the risk to the public is considered low, and there is no concern about the safety of the commercial milk supply, and there is no concern about any risk to consumer health. One of the big factors of being able to say that is pasteurization, which over and over again is proven to inactivate bacteria and viruses like influenza in milk. The big takeaway from that statement is do not drink raw milk.
Dr. Joe Armstrong:Raw milk is not a good thing to take a chance with. That is not a new statement. That's nothing new. Pasteurization is an amazing technology that's been around for a long time, incredibly proven. There is no reason to be drinking raw milk.
Dr. Joe Armstrong:The other thing that brings confidence to that statement is that dairies are required to send only milk from healthy animals for human consumption. That is nothing new either. Abnormal milk needs to not go into the food supply, and that is exactly what's happening. Milk from impacted animals is being diverted or destroyed, so it never reaches the food supply. All of that information combined means that, based on the information we have now, we should be very confident in the safety of pasteurized milk.
Dr. Joe Armstrong:Now to the big question, why are we testing for highly pathogenic avian influenza in some of these herds? Well, I think it's been in the news quite a bit, but we'll do a quick review. There's been an illness or a syndrome in certain dairy herds in the Texas Panhandle and in other locations that has been a mystery. With those herds, that's been going on for quite a while, late January, early February, when all of this started happening in Texas and in a couple other states. They tested for a lot of things.
Dr. Joe Armstrong:You know, they covered their bases to make sure that we didn't have anything too crazy. They looked at all the endemic possibilities. And when they started coming up short on everything, they started thinking outside the box about what could this possibly be, and they started testing for highly pathogenic avian influenza. So we have positive samples. We have tested samples, and they have come back positive for highly pathogenic avian influenza.
Dr. Joe Armstrong:At this time, based on the information we have now, there is not enough to confirm that highly pathogenic avian influenza is the cause of these symptoms and the entire causative agent, the primary thing that's wrong in these dairies experiencing these issues and symptoms. Before we continue too far, we gotta tell you what's going on with these herds because we need to be on the lookout for this case profile so that we can identify it and get more testing done to learn more about what's happening. USDA APHIS wants to know about these things, and I really encourage all of you out there, veterinarians, farmers, anyone who's listening, if you have animals that fit the case profile, please talk to your veterinarian. Veterinarians, you can talk to your state animal health officials and your diagnostic labs for next steps and what to do so that you can follow established, already established, sampling and diagnostic guidelines. These herds in Texas and in other places, what are they experiencing?
Dr. Joe Armstrong:Well, what they're experiencing is that about 10% of the cattle in their herd are affected by this illness. The majority of the cases seem to be mid to late lactation mature cows. And because of that, we're seeing a big loss in milk production. And that lasts usually 14 to 21 days total, where we look at a 10 to 20% reduction in total milk production. The interesting thing about all of this is that at this time, dry cows, fresh cows, heifers, and calves do not appear to be affected, which is a very different disease and illness situation because we usually associate our young stock and fresh cows as where we see our illnesses.
Dr. Joe Armstrong:But this is not that. These illnesses are in our mid to late lactation mature cows. On a cow individual cow level, they usually have symptoms that last between 10 14 days with a peak in that 3 to 5 day window. Those cattle go off feed, which is followed pretty quickly by sudden drop in milk. And in a lot of our very severe cases, we're seeing abnormal milk to where it's thicker, and it's a little yellow, and it looks kinda like colostrum.
Dr. Joe Armstrong:It's very colostrum like milk. You'll also see an accompanying rumination activity decrease, and manure tends to be tacky and dehydrated and dry rather than loose. Unfortunately, on top of that, many of these herds are also experiencing secondary mastitis and pneumonia infections that accompany this illness. The other important thing to note when we look at this case profile is that the cattle that are impacted or they're affected or they become ill, they're not dying. And that is actually creating a little bit of a diagnostic situation that's tricky because when we don't have deads, we usually don't have necropsies.
Dr. Joe Armstrong:So we're not getting a chance to look at as many samples and full sets of tissues as we normally would. Like with a respiratory outbreak, there's deads, and we get to cut those open and see what's going on. But in this case, these cattle are recovering. So that's good overall, but it makes the diagnostic piece tricky. And it's a little different than what we're used to, because we sometimes count on those dead animals to help us figure out what's going on.
Dr. Joe Armstrong:So that's the basic case profile. That's what you need to be looking out for when we're talking about this illness that is currently in Texas and Kansas and a couple other places. Keep an eye out for that. Talk to your veterinarian if you're concerned. Veterinarians, if you're concerned, you need to talk to state animal health officials or the diagnostic labs to get a better handle on what you can send for samples, which you should send for samples, while we're still trying to figure all this out.
Dr. Joe Armstrong:Like I said, again, we have a positive result for highly pathogenic avian influenza. But at this time, we don't have enough information to confirm that that is the causative agent of disease in these cases. So now what? Well, we're waiting on more information, and there's more testing that we're waiting on to get an idea of what's happening at a more detailed level so we have better recommendations to make. For me, one of the biggest aspects of this is that it is highly pathogenic avian influenza that has been identified, and the USDA is fairly confident in saying that it appears that wild birds are the source.
Dr. Joe Armstrong:Now how practical is it to keep birds out of the barn? It's pretty difficult. Absolutely very, very difficult to keep birds and livestock separate. But that being said, what we need to do, and we're looking at basic biosecurity practices, we need to go all the way back to the basics when we're talking about knowing who's on your farm, identifying lines of separation, having dedicated equipment, washing boots, all of those things that are on the basics list. But in addition to those things, we need to be thinking about ways to minimize or eliminate, when possible, poultry and livestock species' access to ponds, wetlands, other water sources that are frequented by waterfowl.
Dr. Joe Armstrong:Migratory waterfowl, I think, are gonna be one of the key pieces of this whole deal. So, any time we can figure out how to eliminate or minimize, as much as possible, the contact between livestock and those species at shared water or shared feedstuffs, that is something we need to take into consideration with this whole situation. Of course, it kinda goes without saying that we need to keep monitoring cattle for signs of illness that fit the case profile. But on the same side of things, we need to monitor domestic poultry for illness. And a lot of times when we're looking at that, highly pathogenic avian influenza can hit poultry hard and fast.
Dr. Joe Armstrong:And what you're gonna see is usually a reduced appetite, reduced water intake, and unexplained deaths in birds. That goes for wild birds as well. Unexplained deaths of wild birds are potential sample opportunities to test. Because we know a little bit about how this virus acts, we also need to be watching cats and other wildlife that are frequently found around livestock facilities for any illnesses or unexplained deaths. Those are also potential samples to take.
Dr. Joe Armstrong:While we're still figuring all this out, I do think it's a good idea to house poultry separately from other livestock species when you can and minimize the access those poultry have to pastures that are going to be grazed by other livestock. Now, one question I got right out of the gate when this dropped was, well, don't we vaccinate for that? And the answer is no. We do vaccinate for something called parainfluenza 3. PI3 is how it's abbreviated most of the time.
Dr. Joe Armstrong:Parainfluenza is a completely different family of viruses from influenza. So we cannot count on that for any sort of protection against influenza. They're not the same family. You cannot count on that for protection. As we wait for more results, as we wait for more data to come in, more guidelines to come out, we are going to dive into some of the weeds of this conversation.
Dr. Joe Armstrong:I think there's a big conversation to be had about influenza in cattle in general, and we need to explore that. There's much more I need to learn about influenza and the history of that disease. We might be bringing on some guests. We might be exploring it on our own. We'll have to see how this all unfolds.
Dr. Joe Armstrong:I'm making it up a little bit as I go. I hope you guys don't mind coming along for the journey. Not the news I wanted to share with you tonight, but it is important that we all are on the same page. We are listening to our official sources and making sure that we understand all the things that come out, all the little pieces that we get, and incorporating them into the big picture. With that, I encourage you to stay tuned for more.
Dr. Joe Armstrong:I also encourage you to continue to check the University of Minnesota Extension website for more information, extension.umn.edu. If you have comments, questions, scathing rebuttals, please send them to the themoosroom@umn.edu or call us at 612-624-3610. You can also always find more information about this type of thing on the USDA APHIS website. I will link it in the show notes. Another great source of information is the board of animal health.
Dr. Joe Armstrong:I will also link that in the show notes. Thank you everybody for listening. I'll keep you updated. Talk to you soon.
