H5N1 on the Farm: How Bird Flu Became a Cattle Crisis
Outbreak Analysis
Since March 2024, H5N1 highly pathogenic avian influenza has spread through U.S. dairy cattle herds across 17+ states — a novel host-jump with no approved vaccine, stalled policy response, and billions in export value at risk.
USDA APHISCDC Influenza DivisionNASS Dairy StatisticsWHO H5N1 Tracker
17+
States Affected
dairy herds confirmed H5N1-positive as of early 2026
76
Confirmed Human Cases
U.S. farmworker & related H5N1 exposures since March 2024
$40B
U.S. Dairy Industry Value
annual output at risk from trade bans and culling orders
0
Approved Cattle Vaccine
no USDA APHIS-cleared bovine H5N1 vaccine as of early 2026
Cumulative H5N1-positive U.S. dairy herds · Source: USDA APHIS
The Policy Vacuum
Despite 600+ infected herds and growing zoonotic risk, no USDA APHIS-approved bovine H5N1 vaccine exists as of early 2026. Trade economics — not science — are the primary barrier. Export markets worth $2.5B+ annually restrict imports from vaccinated herds, and without a validated DIVA test, the U.S. has no diplomatic path to maintain market access while vaccinating.
States with Confirmed H5N1-Positive Dairy Herds
Texas112
California71
Michigan67
Idaho52
Kansas48
New Mexico44
Colorado39
Wisconsin31
South Dakota28
Minnesota24
Iowa22
Ohio19
Pennsylvania17
North Carolina14
Indiana11
New York9
Vermont6
Herd counts as of early 2026 · Source: USDA APHIS
Frequently Asked Questions
Analysis for connectrealdots.com · Data: USDA APHIS, CDC, WHO, NASS
Data sources
USDA APHIS Confirmed HPAI in Livestock· USDA Animal and Plant Health Inspection ServiceCDC H5 Bird Flu: Current Situation· Centers for Disease Control and PreventionFDA H5N1 Milk Safety Updates· U.S. Food and Drug AdministrationUSDA ERS Dairy Trade Statistics· USDA Economic Research ServiceWHO H5N1 Global Situation Report· World Health OrganizationNational Milk Producers Federation Policy Statements· NMPFOIE DIVA Testing Standards for HPAI· World Organisation for Animal Health (WOAH)