Five Rabid Steers on One Minnesota Dairy Farm, 2024: A Skunk Was the Likely Source

The report's visual summary. CDC, MMWR.

In brief

• Rabies infects mammals and is almost 100% fatal unless postexposure prophylaxis (PEP) is given before symptoms begin. Outbreaks in cattle are rare.
• In May 2024, 5 of 35 steers on a Minnesota dairy farm developed neurologic signs of rabies within four weeks — likely from one rabid skunk, though spread between steers can't be ruled out.
• Five people received PEP, and direct costs came to about $35,000, plus the lost animals.
• Where rabies is common and livestock is valuable, vaccinating cattle should be considered.

Background

Rabies is a vaccine-preventable viral disease of the central nervous system, usually spread by the bite of an infected mammal or virus reaching mucous membranes. In the United States, bats, raccoons, foxes, mongooses and skunks carry it. PEP given promptly after exposure is highly effective. Cattle are not routinely vaccinated.

What happened

Rabies cases among steers on the farm, May 11–June 9, 2024. CDC, MMWR.

• May 11: a steer died a few days after drooling, poor coordination, bellowing and head thrashing; no necropsy was done.
• May 13: a second steer with the same signs was euthanized; its brain tested positive for rabies on May 16, and whole genome sequencing identified the North Central Skunk variant. The Minnesota Department of Health and the state Board of Animal Health investigated. The owners recalled smelling a skunk several weeks earlier; no animal had been vaccinated.
• May 18: the herd veterinarian began two-dose postexposure vaccination of the remaining 33 steers; on May 24 they were quarantined for 45 days.
• May 24 and 27: two more steers fell ill, were euthanized and tested positive; the quarantine was extended to 120 days to catch any steer-to-steer spread.
• June 1: the 31 remaining steers got their second dose. June 9: a fifth steer fell ill and died; it wasn't tested. No more died.

The viruses from the three tested steers were closely related. The farm's vaccinated dog, which had reached a steer's carcass, got a booster and was watched for 45 days and stayed healthy; 12 unvaccinated farm cats that might have been exposed were euthanized, following national veterinary guidance.

The people

Health officials interviewed six people. Five were judged possibly exposed: a veterinarian whose glove and skin were punctured while removing a steer's brain; the two farm owners, who had close contact with all the sick steers, including possible saliva contact; and two children under 10 who had been unsupervised where the steers were kept. The four family members got the full PEP series; the veterinarian, already vaccinated, got two boosters.

The Board of Animal Health posted a rabies alert on June 12, and a press release warned of more rabid skunks and cattle in Minnesota in 2024, urging people to vaccinate pets, consider vaccinating livestock, and seek care after possible exposures.

What it means

About 60,000 people in the U.S. are exposed to rabies each year through wildlife and unvaccinated domestic animals. In Minnesota, striped skunks are the main land-based carrier: 42% of skunks tested are positive, and the North Central Skunk variant is the one most often found in pets and livestock.

The steers shared a small pen, so one skunk could have bitten several; with closely related viruses, that is the likely explanation — but five rabid steers in four weeks is highly unusual, and spread between them can't be excluded.

Such losses are usually covered neither by farm insurance nor by the USDA's Livestock Indemnity Program; the owners bore the veterinary bills, the lost steers and extra feed. Cattle are the livestock most often infected, and an economic analysis put U.S. livestock rabies losses at $9.7 million to $40.5 million in 2012–2021. Preventive vaccination makes sense where land-based rabies is common, animals are valuable, and people could be exposed.

Limitations: the first and last steers weren't tested, though their illness and pen make rabies likely; and the source was never confirmed — no skunk was found or tested.

Sources

Based on Carrie Klumb and others, "Rabies Cluster Among Steers on a Dairy Farm — Minnesota, 2024," MMWR Morbidity and Mortality Weekly Report, volume 74, Centers for Disease Control and Prevention; a work of the United States government in the public domain.