State, federal officials respond to fight bird flu in dairy cattle – Journal Advocate

May 9, 2024

Colorado state officials are working with federal authorities to limit the spread of bird flu among dairy cattle.

The first case of highly pathogenic avian influenza (HPAI) in the state was confirmed April 24 in a dairy herd in northeastern Colorado. During an hour-long webinar Wednesday morning State Veterinarian Dr. Maggie Baldwin noted the affected herd was in the northeast corner of our state, but the Colorado Department of Agriculture declined to say in what county the infection was found.

Screen grab from Colorado Department of Agriculture slide stack.

Colorado is the ninth state in which HPAI has been found in dairy cattle. Baldwin said nobody yet knows for sure how the virus has migrated from birds to cattle, but said viral spillover isnt uncommon. In the wild, for instance, HPAI has been found in skunks, foxes and other mammals, but the April 24 discovery is the first in Colorado among domesticated animals.

It has not been detected in any other livestock species, Baldwin said. We dont know of any concern for beef cattle or other species (of livestock.)

Symptoms can include a drop in milk production, loss of appetite, changes in manure consistency, thickened or colostrum-like milk and low-grade fever. Infected cows seem to recover completely after supportive care.

With fair and livestock show season just around the corner, Baldwin said the U.S. Department of Agriculture hasnt issued guidance yet, but hopes to have some definitive answers soon.

We will get information out as quickly as possible but ask people to be patient with us as we work on that, she said. We dont know what the mechanism of transmission in dairy cattle is, but (there are) a lot of really great people working on studying that to give us a better idea of that.

The virus was first detected in March in dairy herds in Texas and Kansas. By late April the virus had showed up in North Carolina, Ohio, Michigan, South Dakota, Colorado, New Mexico and Idaho. The nine-state outbreak in prompted the USDA to issue strict guidelines on April 29 on the movement of dairy cows, especially across state lines. According to that directive, prior to interstate movement, lactating dairy cattle will be required to receive a negative result of testing for influenza type A virus, as performed by an approved National Animal Health Laboratory Network laboratory.

The federal order can be read in detail at the CDOAs website ag.colorado.gov/HPAIcattle. The website also contains detailed information on maintaining biosecurity in dairy herds.

Dr. Rachel Herlihy, the state epidemiologist for the Colorado Department of Public Health and Environment, said the risk of spread to humans is low, but could depend on how much a person is exposed to the virus. She said one person was confirmed with HPAI in Colorado in 2022 and another more recently in Texas. Both cases were very mild, Herlihy said, which indicates that the virus has not yet adapted for human-to-human transmission.

While the virus does show up in an infected cows milk, there is no danger to human transmission. Herlihy said pasteurization continues to be effective in killing virus and bacteria in milk.

HPAI has been a concern for several years but mostly among commercial and back-yard poultry flocks. Millions of commercial birds have had to be destroyed because of outbreaks on poultry farms. The virus is easily transmitted among birds of all types, though some that carry the disease show no symptoms from it. So far HPAI has showed up in 48 states on 1,129 properties and has killed more than 10,000 snow geese, 2,200 Canada geese and 150 raptors and avian scavengers.

Privacy Overview

Strictly Necessary Cookies