Raw dairy has a solid following of people who report wonderful changes to their health when consuming raw, local dairy which is often beyond organic and comes from well-nourished “pets” rather than cattle factories. My family falls into this category of people who have experienced some of these health benefits. However, the risks associated with consuming raw dairy are real and, as those who produce dairy at home for our family, we should be aware of the risks. When do they make sense to take and when don’t they? What we can do to minimize them should we decide to consume raw dairy ourselves?

Brucellosis

What it Is

This contagious bacterial infection has numerous strains infecting different species of animals with varying degrees of virulence. In domestic animals, it is most common in goats but can infect sheep and cattle (and dogs) as well. It causes a wide range of symptoms including

• fever
• sweats
• malaise
• anorexia
• headache
• pain in muscles, joint, and/or back
• fatigue

These symptoms can persist for a long time and some may never go away. It can normally be treated by antibiotics and death from it is rare.

How it is Spread

Transmission of several strains to humans is possible and usually occurs through the consumption of raw milk or raw milk products. Contact with bodily excretions (stillborns, newborns, placenta, etc.) is another method of transmission.

How to Avoid It

Cattle herds in the US are required to have periodic tests for Brucellosis performed and infected animals are usually killed. Vets are required to inoculate young cattle against it, so most animals bred in a commercial dairy or ranch will already be inoculated. The test for Brucellosis requires blood work and culture and can easily be done by a vet.

Have your animal tested for Brucellosis and work with a good vet to monitor your cow’s overall health. Any animal that doesn’t appear in the peak of health should be diagnosed before you consume their milk! The advantage of home dairy production is that you know your animal better than anyone and can tell early on if they don’t appear well.

Most Brucellosis outbreaks have been from larger dairies that produce raw milk products. Animals are necessarily kept in less than the pampered pet style home dairy producers strive to maintain and don’t get the daily individual love and attention your girls should get.

Campylobacter

What it Is

This gastrointestinal bacterial disease is often asymptomatic in carriers and is more common in poultry than in cattle. The symptoms, when present, are vomiting, diarrhea and other dysentery-like symptoms. The symptoms normally last 5-7 days in humans and are self-limiting, being treated with electrolyte replacements, etc. This wouldn’t normally be a life-threatening disease in otherwise healthy people.

How it is Spread

The transmission is fecal-oral. This bacteria is not resistant to normal stomach acids and has to be present in the food source in very high quantities to cause infection.

How to Avoid It

Limit access of poultry to areas where cow feed is stored.

The bacteria are not present in the milk inside the cow but may be transferred to the milk during the milking process if good milking hygiene is not practiced. Follow good milking practices!

Cryptosporidium

What it Is

This microscopic parasite is related to malaria but does not require an insect vector to complete its life cycle. The symptoms can be GI-related and also present respiratory complications like coughing. The infection in otherwise healthy individuals is acute but short-lived.

How it is Spread

The cyst form of the parasite is present for up to five weeks in the fecal matter of infected individuals and is very resistant to standard water treatment procedures like chlorine. Infection from contaminated city water is more common than raw dairy.

How to Avoid It

Practice good hygiene with your milking and don’t consume milk from a sick animal!

E. coli

What it Is

This ubiquitous bacteria is found in the GI tract of nearly every species of animal and persists in most water sources prior to treatment.

How it Spreads

Its method of transmission is fecal-oral.

How to Avoid It

Practice good milking hygiene and if you think your milk may have been contaminated with fecal matter during the milking process, feed it to the chickens or pig, or use it in some form that heats it to safe levels prior to consumption.

Listeria

What it Is

This serious bacterial infection is most dangerous to the very old, the very young (or pregnant women) or those with otherwise compromised immune systems. The main symptoms in humans are blood infection (sepsis) or meningitis. If your cow presents any of the following symptoms, seek help from a qualified vet before consuming her milk. 

• Depression
• Loss of appetite
• Fever
• Lack of coordination 
• Isolation from herd
• Salivation
• Facial paralysis
• Abortions
• Stillbirths

The most common form of the bacteria found in ruminants is L. ivanovii and rarely causes disease in humans.

How it is Spread

This is also fecal-oral. It is often spread by rodents who may serve as asymptomatic carriers.

How to Avoid It

The incidence in cattle is greatly reduced by feeding high-quality (unspoiled and low-pH) food, which allows the animals immune systems a leg up in battling infection. Control the presence of rodents in your environment to avoid spreading bacteria (good practices for any disease prevention!). Pasteurization doesn’t always knock out the Listeria bacteria and recent outbreaks have occurred from the consumption of contaminated commercial dairy.

Salmonella

What it Is

This bacteria is often present in the environment without causing illness. In infected cattle look for a watery, sometimes bloody, diarrhea and general listlessness or loss of appetite. Another common sign of infection is stillbirth or the death of very young animals.

How it is Spread

The salmonella bacteria can be expressed in the milk (not only through fecal matter) of infected mammals (human or ruminant) and can persist indefinitely in asymptomatic hosts. It is a concern with the consumption of any raw foods, especially improperly handled eggs. It is a serious danger to the very young or immunocompromised.

How to Avoid It

You can ask your vet for a fecal test if you have any reason to suspect salmonella in your girls but if you don’t plan to test every batch of milk prior to consumption,  don’t feed raw milk to those most at risk for infection!

Mastitis

What it Is

There are a number of bacteria (mostly Staph and Strep family) that cause mastitis in cattle and can also cause GI discomfort in humans consuming raw milk from infected animals. Mastitis causes inflammation of the milk ducts in the infected udder, changes the properties of the milk, reduces production, sheds the infecting bacteria in the milk, and can lead to sepsis, gangrene or death of the animal if left untreated. We have a more in-depth post on this disease and how to avoid it altogether!

How it is Spread

The bacteria which cause mastitis travel through an open nipple into the udder and may cause an infection if the immune system of the animal is not able to irradicate them. Staph, strep and e-coli are all present in the environment to some degree and transmission via poor milking practices is common. Those opting to use milking machines need to practice extra care not to cause mastitis via improper use of the vacuum action which may introduce bacteria from the surface of the teat into the udder.

How to Avoid It

Practice good environmental sanitation, good milking habits and keep your girls in the peak of health. Some strains are known to cause subclinical infections which means that you will want to test your girls regularly for mastitis. Thankfully, this is quick and easy to do yourself at home. Click here for an in-depth look at how to minimize the risk of mastitis in your girls and what some treatment options are.

Conclusion

This list can seem frightening but we are fortunate to live in an age when we can easily (and fairly cost-effectively) test for, identify, and (usually) treat these pathogens in our home dairy animals. You can meet or exceed the government requirements of commercial dairy testing very easily and you’re much more motivated to protect your family in this way than any dairyman can be.

The risk of foodborne bacterial or parasitic infections exists in any food you consume regardless of whether it comes wrapped in plastic from the supermarket or from your own milking parlor. I trust the milk from my happy, healthy Jersey or Saanen who I see and touch and feed and sing to every day more than I would any milk from a commercial dairy with dozens or hundreds of cows and a tight bottom line who has to make snap judgments on cows based only on dollars and cents and a long list of government regulations.

As we mentioned elsewhere the goal of home food production isn’t (and shouldn’t be) sterilization. Many beneficial bacteria readily colonize milk and will usually outgrow the pathogenic ones. Healthy immune systems require exercise and practice. Pasteurization purports to remove the risk from consuming milk (although it doesn’t even entirely accomplish that) but at the cost of removing the benefits of the beneficial bacteria on the digestibility, flavor, and usefulness of the milk. There is a place for the process of pasteurization but those who are informed about the risks and are able to mitigate them can enjoy the best of both worlds in consuming a superior product in a safe manner!