Common Zoonotic Diseases on Dairy Farms

Some diseases pass between cattle and people. Knowing which ones to be aware of, and a few steady habits, protects you, your family and your workers.

Key points

Manure, birth fluids, sick calves and raw milk are the main routes.
Hand washing, gloves and clean boots prevent most problems.
Treat abortions and sick calves as possible infection risks.
Tell your doctor you work with cattle if you become ill.

What zoonotic means on a dairy

A zoonotic disease is one that can pass from animals to people. On a dairy, the routes include manure, raw milk, birth fluids, contact with sick animals, contaminated water and, for a few diseases, airborne dust or droplets.

Most farm work is safe when basic hygiene is followed. The risk rises with newborn calves, calving and abortions, sick animals, and anyone with a weakened immune system, who should talk to their doctor about farm tasks.

This guide is general education. Your doctor and veterinarian can give advice that fits your own health and herd. Keep a first-aid kit and a list of emergency numbers where workers can find them, and make sure everyone knows to report any bite, scratch or splash promptly.

Diseases to know about

Several well-known germs and parasites can pass from cattle to people. Not every farm has all of them, and your vet can tell you which matter in your area.

Ask your vet which of these have been found in your region or herd, and what signs to watch for in animals and people.

Do not try to diagnose any of these yourself. Many of them cause vague signs in both animals and people, and only testing can tell what is going on.

Salmonella and E. coli from manure and calves
Cryptosporidium, a common cause of calf scours
Ringworm, a skin infection from contact
Leptospirosis, spread through urine and contaminated water
Brucellosis and Q fever, linked to birth materials and raw milk
Rabies, a rare but serious risk from wild animals
Tuberculosis, a reportable disease with its own rules

Calving, abortions and birth fluids

Calving is a high-risk time because birth fluids and afterbirth can carry germs. Wear gloves and protective clothing during assistance and cleanup, wash up well afterward, and keep children out of the calving area.

Any abortion should be treated as possibly infectious until your vet says otherwise. Handle tissues with gloves, keep dogs and cats away, and ask your vet about testing and about reporting rules. Gloves are only useful if they are changed and hands are washed afterward, so keep plenty on hand and a bin for used ones near the calving area.

Calves, manure and hand hygiene

Calf scours often involve germs that also affect people. Wash hands with soap and clean water after handling calves, feeding, cleaning pens and before eating, drinking, smoking or touching your face.

Keep eating and drinking areas away from animal spaces. Provide a hand-washing station with soap and single-use towels, and make it easy for children and visitors to use it.

Wash hands before breaks and meals
Use dedicated boots for animal areas
Leave dirty clothes at the door
Wear gloves for sick animals and birth work

Raw milk and animal products

Drinking raw milk carries a risk of illness, and laws about selling or sharing it differ by state. Check with your state department of agriculture about what is allowed in your area.

If your family drinks milk from your own cows, talk with your doctor and vet about the risks and about testing. Milk from sick or treated cows must never be consumed or sold while withdrawal times apply.

Protecting workers and when to get help

Train family and employees on the habits above, and provide gloves, boots and washing supplies. Pregnant women, young children, older adults and people with weakened immunity may face higher risk and should speak with a doctor before doing tasks such as calving or calf care.

If someone on the farm develops fever, diarrhea, a skin rash, flu-like illness or other symptoms after animal contact, tell their doctor that they work with cattle. That detail can change the tests and the advice. Ask your doctor about vaccines that suit your own situation, such as tetanus, and keep personal records up to date for everyone who works with animals.

Cleaning, clothing and farm visitors

Clothing and boots carry germs home. Keep work clothes and boots separate from household laundry and living areas, and wash them regularly with hot water and soap as the label directs.

Visitors, school groups and children need clear rules. Show them where to wash, keep them out of calving and sick pens, and do not allow food or drink near animals.

Change boots and coveralls before entering the house
Keep children away from calving and sick animals
Wash small cuts and scrapes right away and cover them
Keep pets and farm cats out of feed and milk areas
Control rodents and wild animals around feed storage

When to get help: Call your veterinarian about abortions, ongoing calf scours and any suspected reportable disease. Call your doctor about illness in people, and your state department of agriculture or health department about raw milk and reporting rules.

Sources and further reading

Organization homepages are linked so you can search them for current guidance on this topic.

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