Does Milk Have Blood In It

In this brief article, we will answer the question, “does milk have blood in it?” and will also highlight the potential reasons for blood in the milk, how this can be prevented, and how farmers and factories ensure the safety and quality of milk.

Does Milk Have Blood In It?

No, regular milk obtained at the grocery store or available at farms does not have blood in it. Milk containing even a hint of blood in it is not fit for consumption. 

If any blood or pus makes it into milk during the milking process, it is immediately disposed of by the farmer instead of making its way to a factory. By definition, BTSCCs are the number of white blood cells (primarily macrophages and leukocytes), secretory cells, and squamous cells per milliliter of raw milk. BTSCCs are used as measures of milk quality and as indicators of overall udder health. To ensure high-quality dairy products, BTSCCs are monitored in milk shipments using standards outlined in the U.S. Pasteurized Milk Ordinance (PMO). In the United States, the legal maximum BTSCC for Grade A milk shipments is 750,000 cells/mL (1).

Moreover, abnormal milk obtained from cows is collected in separate vessels or buckets and discarded.

What Causes Blood In Milk?

Pinkish or reddish milk obtained from cows contains blood and is usually the result of a rupture in the small mammary blood vessels. This may be the result of edema (water retention) or udder swelling. If the gland is milked regularly, the issue is often resolved within one to two weeks.

The presence of ‘frank blood’ in a single quarter of milk is most likely caused by severe, acute mastitis or trauma to the udder. In this case, milking must be discontinued until the hemorrhaging resolves. Inflammation of the mammary glands in cows is a pathology that is often diagnosed, especially during lactation, when the udder is experiencing heavy loads. Mastitis leads to a decrease in milk productivity, and in some cases causes culling of animals (2). Milk from cows with mastitis have elevated somatic cellular cells and is often withheld from the bulk tank (1). Also, Intramammary antibiotics must be administered to promote healing and prevent infection. 

Is There Cow’s Blood in Milk Products, Say Chocolate Milk?

A rather unsettling rumor, but thankfully, the Food and Drug Administration (FDA) confirms that there is no margin and acceptance for blood in any milk product. To ensure high-quality dairy products, BTSCCs are monitored in milk shipments using standards outlined in the U.S. Pasteurized Milk Ordinance (PMO). If a producer has two out of four shipments that test above the maximum white blood cells (usually tested 30 to 45 days apart), a written notice is issued and an additional sample is tested within 21 days. If three of the last five counts exceed the maximum BTSCC, more severe regulatory action is required (1). 

Certain people claimed that when cows were milked, a huge amount of blood would sometimes come along with the milk. Since the tainted and possibly infected milk was non-salable, manufacturers of pre-packaged chocolate milk bought it at discounted rates and disguised it with cocoa.

All these rumors proved to be a hoax so rest assured that milk containing blood is not sold anywhere to anyone for manufacturing any dairy products. 

How Should Udder Infections and Injury Be Treated To Prevent Milk In Blood?

Wounds on the surface of the udder should firstly be cleaned using an antiseptic solution. They must be dealt with as open wounds and regularly sanitized with antiseptic sprays or powders. If the teats are also injured or wounded, the application of adhesive tape can help boost the healing process. 

Wounds on the openings of the teats must be cleaned and sanitized before the application of antiseptic cream. Also, they must be bandaged after milking. Mastitis is caused by bacteria, mainly staphylococci and streptococci, entering the udder and causing damage (1).

Injuries are also high-risk areas for infections, hence prophylactic treatment with intramammary antibiotics must be given to prevent the development of mastitis (inflammation of breast tissue).

Cuts on the large milk vein must be addressed as an emergency since this may lead to severe hemorrhage. In this case, immediate compression and ligation of the lacerations must be done.

In case of deeper wounds of the teats and udder, prompt (within six hours) cleansing must follow suturing or stapling the area under local anesthesia while the animal is adequately sedated or restrained. 

If the wound involves the teat cistern, a self-retaining teat cannula with a removable cap might be inserted into the teat for the first 24 hours. This prevents milk from seeping through the wound (which delays healing) and also aids milking. Antibiotic preparations must also be administered. However, the best way to deal with infections is with a rapid mastitis test to detect cows with a latent form of mastitis in the early stages of the disease, which will allow timely treatment of this pathology, as well as evaluate the effectiveness of treatment (1).

How Do Farmers Ensure the Safety and Hygiene of Milk?

High hygiene during milking is one of the factors that influences the incidence of mastitis and therefore the possibility of milk contamination with white blood cells (1).  Premilking teat disinfection has been shown to reduce environmental bacteria on the teat surface, reduce bacterial counts in milk, and may decrease the incidence of new infections (3).

After obtaining milk from healthy cows, here’s how farmers ensure that the milk they send to farms and factories is clean and safe for consumption. 

  • Prior to entering the collection vat, the milk passes through a filter to remove any unseen and unwanted materials, including milk clots and organic substances.
  • Sensory testing is then conducted on the milk before it goes into a milk tanker for detecting any foreign materials, discoloration, or foul odor. Milk that fails this test is immediately rejected.
  • Once at the factory, the milk is again filtered and passed through a series of tests to determine its quality. For instance, a ‘Bulk Milk Cell Count’ is conducted on each farmers’ vat, which determines the number of white blood cells in the milk; a higher number could indicate mastitis. 
  • Regular testing is also performed to detect bacterial cells and measure the milking plant hygiene, milk cooling efficiency, and milking cleanliness. 

Dairy farmers must uphold an approved food safety program within their farms to meet state dairy authority requirements, and dairy farms are audited to check compliance with this program. 

Moreover, dairy factories provide suppliers with support staff that makes sure they abide by the food safety and quality requirements and ensure the absence of blood and pus in milk.


In this brief article, we answered the question, “does milk have blood in it?” and also highlighted the potential reasons for blood in the milk, how this can be prevented, and how farmers and factories ensure the safety and quality of milk.

If you have any questions or comments please let us know.


  1. Determining U.S. Milk Quality Using Bulk-Tank Somatic Cell Counts. United States Department of Agriculture, 2017.
  2. Palii, А. P., et al. Species composition of microbiota of cows udder and raw milk quality at mastitis. Ukrain J Ecol, 2020,10, 78-85.
  3. Milking Procedures on U.S. Dairy Operations. United States Department of Agriculture, 2007