Signs of HPAI Infection in Cattle

USDA has confirmed an outbreak of Highly Pathogenic Avian Influenza in dairy cattle in eight states. Dr. Beth Thompson, South Dakota State Veterinarian, talks about a number of the common signs of infection that producers need to watch for.

Dr. Thompson says, “So, it’s decreased milk production, abnormal milk, and the cow might dry off early. There might be a fever. The cow is going to have a decreased feed consumption. Her rumen is going to slow down. Well, she’s not eating, so her rumen’s gonna slow down. Then, on the back end, so to speak, she’s going to have either diarrhea or a change in the manure consistency. There have been a few talking about a nasal discharge, but this virus in dairy doesn’t seem to be causing respiratory issues. The virus is going for the mammary tissue, and we’re finding it in the milk.”

The onset of the disease seems to happen quickly. The good news is that HPAI can be treated and so far hasn’t caused large numbers of cattle to die after infection. She says, “My understanding – I haven’t seen the data – is it can be treated. Dairies, they’ve got hands-on, eyes on dairy cattle every day, a couple of times when they come through the milking parlor. So, generally speaking, the dairy will pull her off and put her in the sick pen, give her supportive care, give her fluid make sure she’s eating, maybe give her some boluses, and she’ll come back around. In a couple of weeks or a little bit more, she’ll come back. It’s my understanding that these dairy cows, for the most part, are coming back into production. There have been a few mortalities, but nothing significant at all.”

That’s good news when you compare it to the devastation the disease wreaks on poultry farms. While it’s not completely surprising, it’s not often a virus will jump between species.

Dr. Thompson says, “It’s not all that common, but we are talking about influenza, and that’s a virus. Viruses are smart. They will adapt if they don’t find enough hosts or their hosts aren’t providing a home for them. Viruses will get into a host and then start replicating. That’s what viruses do. Now, why this virus is now being found in dairy, I go down the road of we’ve got so much environmental contamination out there with the wild waterfowl and other wildlife.”

She says protecting dairy herds from wild birds can be a big challenge. She says, “I think the last few years with our poultry farmers dealing with that conundrum of how to keep anything to do with wild birds from entering into their barns, the same is true of dairies, and they’re much more open, especially up here in the Dakotas, Minnesota, and other places. It’s hard to keep wild birds away from any of the domestic animals. Cleaning up feed spills and making sure there are no ponds around that the wild birds might congregate around are just a couple of the examples of things that farmers can be doing.”

Story courtesy of the NAFB News Service