Mastitis in dairy cattle

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Gangrenous mastitis in a cow after 10 days. Green arrow indicates complete necrosis of the teat. Yellow arrows indicate the limits of the gangrenous tissue, but the necrotic area is not well delimited on the upper part of the udder. Mamite a grangrin vatche pes fritches.jpg
Gangrenous mastitis in a cow after 10 days. Green arrow indicates complete necrosis of the teat. Yellow arrows indicate the limits of the gangrenous tissue, but the necrotic area is not well delimited on the upper part of the udder.
Dairy cow with gangrenous mastitis . rear quarter Cow Gangrenous mastitis.jpg
Dairy cow with gangrenous mastitis . rear quarter

Bovine mastitis is the persistent, inflammatory reaction of the udder tissue due to physical trauma or microorganisms infections. Mastitis, a potentially fatal mammary gland infection, is the most common disease in dairy cattle in the United States and worldwide. It is also the most costly disease to the dairy industry. [1] Milk from cows suffering from mastitis has an increased somatic cell count. Prevention and control of mastitis requires consistency in sanitizing the cow barn facilities, proper milking procedure and segregation of infected animals. Treatment of the disease is carried out by penicillin injection in combination with sulphar drug.



Mastitis occurs when white blood cells (leukocytes) are released into the mammary gland, usually in response to bacteria invading the teat canal or occasionally by chemical, mechanical, or thermal trauma on the udder. Milk-secreting tissue and various ducts throughout the mammary gland are damaged due to toxins released by the bacteria resulting in reduced milk yield and quality.


the quarter with Gangrenous mastitis Gangrenous teat.jpg
the quarter with Gangrenous mastitis
A gangrened udder (which sloughed naturally) Mamite grangrin moirt pes.JPG
A gangrened udder (which sloughed naturally)

This disease can be identified by abnormalities in the udder such as swelling, heat, redness, hardness, or pain (if it is clinical). Other indications of mastitis may be abnormalities in milk such as a watery appearance, flakes, or clots. When infected with sub-clinical mastitis, a cow does not show any visible signs of infection or abnormalities in milk or on the udder. [1]

Mastitis-causing bacteria

Bacterial cells of Staphylococcus aureus, one of the causal agents of mastitis in dairy cows. Its large capsule protects the organism from attack by the cow's immunological defenses. Staphylococcus aureus, 50,000x, USDA, ARS, EMU.jpg
Bacterial cells of Staphylococcus aureus , one of the causal agents of mastitis in dairy cows. Its large capsule protects the organism from attack by the cow's immunological defenses.

Bacteria that are known to cause mastitis include:

These bacteria can be classified as environmental or contagious depending on mode and source of transmission.

Types of mastitis

Mastitis may be classified according two different criteria: either according to the clinical symptoms or depending on the mode of transmission.

Clinical symptoms
Mode of transmission


Mastitis is most often transmitted by repetitive contact with the milking machine, and through contaminated hands or materials.

Another route is via the oral-to-udder transmission among calves. Feeding calves on milk may introduce some mastitis causing bacteria strain in the oral cavity of the calf where it will stay dormant until it is transmitted elsewhere. Since grouped calves like to stimulate suckling, they will transmit the bacteria to the udder tissue of their fellow calves. The bacteria will lay dormant in the udder tissue as the calf grows until it begins to lactate. That is when the bacteria activates and causes mastitis. This calls for strict calf management practices to curb this route of transmission.

Effects on milk composition

Serous exudate from udder in E. coli mastitis in cow (left), in comparison to normal milk (right) Mamite a colibacile laecea.jpg
Serous exudate from udder in E. coli mastitis in cow (left), in comparison to normal milk (right)

Mastitis can cause a decline in potassium and an increase in lactoferrin. It also results in decreased casein, the major protein in milk. As most calcium in milk is associated with casein, the disruption of casein synthesis contributes to lowered calcium in milk. The milk protein continues to undergo further deterioration during processing and storage. [7] Milk from cows with mastitis also has a higher somatic cell count. [8] Generally speaking, the higher the somatic cell count, the lower the milk quality.



A plastic paddle used in the California mastitis test. California Mastitis Test Schalmtestplatte.jpg
A plastic paddle used in the California mastitis test.

Cattle affected by mastitis can be detected by examining the udder for inflammation and swelling, or by observing the consistency of the milk, which will often develop clots or change color when a cow is infected. [9]

Another method of detection is the California mastitis test, which is designed to measure the milk's somatic cell count as a means for detecting inflammation and infection of the udder. [10]


Treatment is possible with antibiotics, but milk from such cows is not marketable until drug residues have left the cow's system. Antibiotics may be systemic (injected into the body), or they may be forced upwards into the teat through the teat canal (intramammary infusion). Cows being treated may be marked with tape to alert dairy workers, and their milk is syphoned off and discarded. To determine whether the levels of antibiotic residuals are within regulatory requirements, special tests exist. Vaccinations for mastitis are available, but as they only reduce the severity of the condition, and cannot prevent reoccurring infections, they should be used in conjunction with a mastitis prevention program.


Practices such as good nutrition, proper milking hygiene, and the culling of chronically infected cows can help. Ensuring that cows have clean, dry bedding decreases the risk of infection and transmission. Dairy workers should wear rubber gloves while milking, and machines should be cleaned regularly to decrease the incidence of transmission.


A good milking routine is vital. This usually consists of applying a pre-milking teat dip or spray, such as an iodine spray, and wiping teats dry prior to milking. The milking machine is then applied. After milking, the teats can be cleaned again to remove any growth medium for bacteria. A post milking product such as iodine-propylene glycol dip is used as a disinfectant and a barrier between the open teat and the bacteria in the air. Mastitis can occur after milking because the teat holes close after 15 minutes if the animal sits in a dirty place with feces and urine.

Industry costs

This disease costs the US dairy industry about 1.7 to 2 billion USD each year. [7]

Related Research Articles

Dairy Organization that processes milk

A dairy is a business enterprise established for the harvesting or processing of animal milk – mostly from cows or buffaloes, but also from goats, sheep, horses, or camels – for human consumption. A dairy is typically located on a dedicated dairy farm or in a section of a multi-purpose farm that is concerned with the harvesting of milk.

Mastitis Medical condition

Mastitis is inflammation of the breast or udder, usually associated with breastfeeding. Symptoms typically include local pain and redness. There is often an associated fever and general soreness. Onset is typically fairly rapid and usually occurs within the first few months of delivery. Complications can include abscess formation.

Dairy farming

Dairy farming is a class of agriculture for long-term production of milk, which is processed for eventual sale of a dairy product.


An udder is an organ formed of two or four mammary glands on the females of dairy animals and ruminants such as cattle, goats, and sheep. An udder is equivalent to the breast in primates and elephantine pachyderms. The udder is a single mass hanging beneath the animal, consisting of pairs of mammary glands with protruding teats. In cattle, there are normally two pairs, in sheep, goats and deer, there is one pair, and in some animals, there are many pairs. In animals with udders, the mammary glands develop on the milk line near the groin, and mammary glands that develop on the chest are generally referred to as breasts.

Dairy cattle cattle bred to produce milk

Dairy cattle are female cattle bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cows generally are of the species Bos taurus.

Somatic cell count

A somatic cell count (SCC) is a cell count of somatic cells in a fluid specimen, usually milk. In dairying, the SCC is an indicator of the quality of milk—specifically, its low likeliness to contain harmful bacteria, and thus its high food safety. White blood cells (leukocytes) constitute the majority of somatic cells in question. The number of somatic cells increases in response to pathogenic bacteria like Staphylococcus aureus, a cause of mastitis. The SCC is quantified as cells per milliliter. General agreement rests on a reference range of less than 100,000 cells/mL for uninfected cows and greater than 250,000 for cows infected with significant pathogen levels. Several tests like the PortaSCC milk test and The California mastitis test provide a cow-side measure of somatic cell count. The somatic cell count in the milk also increases after calving when colostrum is produced.

Staphylococcus caprae is a Gram-positive, coccus bacteria and a member of the genus Staphylococcus. S. caprae is coagulase-negative. It was originally isolated from goats, but members of this species have also been isolated from human samples.

<i>Neospora</i> Genus of single-celled organisms

Neospora is a single celled parasite of livestock and companion animals. It was not discovered until 1984 in Norway, where it was found in dogs. Neosporosis, the disease that affects cattle and companion animals, has a worldwide distribution. Neosporosis causes abortions in cattle and paralysis in companion animals. It is highly transmissible and some herds can have up to a 90% prevalence. Up to 33% of pregnancies can result in aborted fetuses on one dairy farm. In many countries this organism is the main cause of abortion in cattle. Neosporosis is now considered as a major cause of abortion in cattle worldwide. Many reliable diagnostic tests are commercially available. Neospora caninum does not appear to be infectious to humans. In dogs, Neospora caninum can cause neurological signs, especially in congenitally infected puppies, where it can form cysts in the central nervous system.


Buffalopox is caused by buffalopox virus (BPXV); it is a Poxviridae for which the natural host is buffalo. It mainly infects buffalo but has been known to infect cows and humans. It is classified in the Orthopoxvirus (OPV) genus and the subfamily Chordopoxvirinae. The appearance of buffalopox follows a pattern and is described as emerging and re-emerging, it commonly occurs in sporadic and epidemic forms in domestic and commercial farm settings.


Cefquinome is a fourth-generation cephalosporin with pharmacological and antibacterial properties valuable in the treatment of coliform mastitis and other infections. It is only used in veterinary applications.

The United States raw milk debate concerns issues of food safety and claimed health benefits of raw milk, and whether authorities responsible for regulating food safety should prohibit sale of raw milk for consumption.

<i>Streptococcus canis</i> Species of bacterium

Streptococcus canis is a group G beta-hemolytic species of Streptococcus. It was first isolated in dogs, giving the bacterium its name. These bacteria are characteristically different from Streptococcus dysgalactiae, which is a human-specific group G species that has a different phenotypic chemical composition. S. canis is important to the skin and mucosal health of cats and dogs, but under certain circumstances, these bacteria can cause opportunistic infections. These infections were known to afflict dogs and cats prior to the formal description of the species in Devriese et al., 1986. However, additional studies revealed cases of infection in other mammal species, including cattle and even humans. Instances of mortality from S. canis in humans are very low with only a few reported cases, while actual instances of infection may be underreported due to mischaracterizations of the bacteria as S. dysgalactiae. This species, in general, is highly susceptible to antibiotics, and plans to develop a vaccine to prevent human infections are currently being considered.

Norwegian Red Breed of cattle

Norwegian Red is a breed of dairy cattle developed in Norway since 1935. Since the 1970s, breeders strongly emphasized functional and production traits resulting in excellent production combined with world-leading performance in health and fertility traits. Norwegian Red cows can have either a red and white or black coat and have a high proportion of genetically polled animals.


Metritis is inflammation of the wall of the uterus, whereas endometritis is inflammation of the functional lining of the uterus, called the endometrium. The term pelvic inflammatory disease (PID) is often used for metritis.

Pathogenic <i>Escherichia coli</i> Strains of E. coli that can cause disease

Escherichia coli is a gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most E. coli strains are harmless, but pathogenic varieties cause serious food poisoning, septic shock, meningitis, or urinary tract infections in humans. Unlike normal flora E. coli, the pathogenic varieties produce toxins and other virulence factors that enable them to reside in parts of the body normally not inhabited by E. coli, and to damage host cells. These pathogenic traits are encoded by virulence genes carried only by the pathogens.

Staphylococcus chromogenes is a Gram-positive, coagulase-negative member of the bacterial genus Staphylococcus consisting of clustered cocci. The species is associated with mastitis in dairy animals.

Pseudocowpox is a disease caused by the Paravaccinia virus or Pseudocowpox virus, a virus of the family Poxviridae and the genus Parapoxvirus. Humans can contract the virus from contact with livestock infected with Bovine papular stomatitis and the disease is common among ranchers, milkers, and veterinarians. Infection in humans will present with fever, fatigue, and lesion on the skin.

Mycoplasma bovis is one of 126 species of genus Mycoplasma. It is the smallest living cell and anaerobic organism in nature. It does not contain any cell wall and is therefore resistant to penicillin and other beta lactam antibiotics.

Mark Bryan (veterinarian)

Mark Bryan is a veterinarian and researcher working in New Zealand. He is a director of VetSouth, one of two clinical research clinics in the South Island and Adjunct Senior Lecturer in Dairy Cattle Medicine at Massey University. In 2013 he was a finalist in the Ernst & Young Entrepreneur of the Year.

Dry cow

A dry cow refers to a dairy cow that is in a stage of their lactation cycle where milk production ceases prior to calving. This part of their lactation cycle is referred to as the cows dry period and typically last between 40 and 65 days. Dry cows are typically divided into two groups: far-off and close-up. Once the cow has entered this stage, producers will seal the cows teat while following a veterinarian recommended, dry cow therapy for their herd. This dry period is a critical part of their lactation cycle and is important for the cows health, the newborn calf and future milk production as it allows the cow time to rest, eat and prepare for birth. During this time the cow will produce colostrum for the newly born calf.


  1. 1 2 Department of Animal Science. "Mastitis in Dairy Cows" (PDF). MacDonald Campus of McGill University. Archived from the original (PDF) on July 8, 2003. Retrieved 4 February 2010.
  2. "Teat Disinfection Facts". NMC. Archived from the original on 3 February 2010. Retrieved 4 February 2010.
  3. "A Practical Look at Environmental Mastitis". Archived from the original on 3 December 2010. Retrieved 4 February 2010.
  4. "Mastitis Pathogen Notes: Pasteurella species". Retrieved 4 February 2010.
  5. "Mastitis Pathogen Notes: Arcanobacterium pyogenes". Archived from the original on 19 August 2003. Retrieved 4 February 2010.
  6. 1 2 "Mastitis Pathogen Notes: Proteus species". Archived from the original on 17 April 2002. Retrieved 4 February 2010.
  7. 1 2 Jones, G. M.; Bailey, T. L. "Understanding the Basics of Mastitis". Virginia Cooperative Extension. Archived from the original on 2 November 2019. Retrieved 4 February 2010.
  8. Kandasamy S, Green BB, Benjamin AL, Kerr DE (December 2011). "Between-cow variation in dermal fibroblast response to lipopolysaccharide reflected in resolution of inflammation during Escherichia coli mastitis". Journal of Dairy Science. 94 (12): 5963–75. doi: 10.3168/jds.2011-4288 . PMID   22118085.
  9. Laven, Richard. "Mastitis Control and Management: Mastitis Part 4 - Detecting and Treating Clinical Mastitis". National Animal Disease Information Service. Archived from the original on 30 January 2016. Retrieved 27 February 2015.
  10. "Detection of Mastitis". Department of Animal Sciences. University of Illinois at Urbana–Champaign . Retrieved 27 February 2015.

Further reading