Dairy Diseases: Understanding Mastitis In Dairy Cows

A healthy herd is a profitable herd. Dairy farming profitability will only be guaranteed when the herd is healthy. One of the major health setbacks dairy farmers have to deal with is mastitis.

Mastitis manifests in dairy cattle when leukocytes (white blood cells) are released in a cow’s mammary gland. The leukocytes are released to respond to bacteria attacks in the teat canal, ducts and milk secreting tissue.

What Is Mastitis?

Mastitis is the persistent inflammation of the udder, breast and mammary gland. It’s typically common in females but may also be found in men. Mastitis sometimes involves infections and will mainly lactating cows explaining why it’s a major concern among dairy farmers.

Mastitis is not only common in dairy farming but is also potentially fatal. This is not to mention the costs incurred in treating it and the losses suffered by dairy farmers. You just do not want to deal with mastitis in cows when you are in commercial dairy farming but when it does strike you need to know how to go about it and we have a guide.

What Causes Mastitis In Dairy Cows?

Mastitis (the inflammation of cow udder and mammary glands) is caused by infections. These infections are as a result of the introduction of bacteria introduced from injuries, environmental contact or milking process.

Mastitis causing bacteria include;

  1. Pseudomonas aeruginosa
  2. Corynebacterium bovis
  3. Staphylococcus epidermidis
  4. Streptococcus uberis
  5. Streptococcus agalactiae
  6. Mycoplasma spp. (including Mycoplasma bovis)
  7. Brucella melitensis
  8. Escherichia coli (E. coli)
  9. Klebsiella pneumonia
  10. Staphylococcus aureus
  11. Klebsiella oxytoca
  12. Enterobacter aerogenes
  13. Pasteurella
  14. Prototheca zopfii (achlorophyllic algae)
  15. Proteus spp
  16. Prototheca wickerhamii (achlorophyllic algae)

A cow’s udder becomes infected when the teats get exposed to pathogen and the pathogen penetrates to the teat ducts. As the bacteria multiply, the exposure increases. This multiplication infects other quarters.

Symptoms Of Mastitis In Dairy Cows

Mastitis in dairy cows can manifest in a number of ways ranging from mild to severe. The degree of infection and symptoms will depend on a number of factors which include cow’s immunity, pathogens present, environmental conditions, climatic conditions and nutrition among others. Some of the common signs and symptoms include;

  • Lack of appetite
  • Reduced milk production
  • Increased body temperature
  • Dehydration and diarrhea
  • Reduced mobility
  • Sunken eyes
  • Udder swelling, hardness, pain and heat
  • Watery milk appearance, clots, pus and flakes

Note: In severe conditions, the cow will appear to be very ill and may not move of feed due to the pain associated with mastitis infections.

The Different Types Of Mastitis

The classification of mastitis can be pegged on two aspects; mode of transfer and clinical symptoms.

Mode Of Transmission

Contagious Mastitis

Contagious mastitis which is also known as cow to cow mastitis is generally spread from one cow to the other. The mastitis bacteria stay in teat and udder lesions and have poor survival in the environment when not associated with the gland or skin. It is the mastitis that commonly manifests as subclinical or chronic mastitis.

When cleaning the teats and udder, the towel or sponge picks up the mastitis bacteria and are transmitted to the next cow if the same towel or sponge is used. It may also be transmitted by the milkers’ hands or even the milk machine. Hygiene therefore needs to be maintained at all stages especially when signs of mastitis in dairy cows have been seen.

Environmental Mastitis

If you have not had a case of mastitis in your farm where could the bacteria come from? Well, environmental mastitis may be the answer. This is referred to as environment to cow mastitis as the bacteria are found in the environment and end up affecting the cow. It is a fact that as the incidence of contagious mastitis decreases, that of environmental mastitis increases. In most cases, the bacteria will be found in the soil, cow beddings, feces or drinking water.

As the cow moves around, eats, drinks or even sleeps, environmental mastitis can easily get to the teats and udder especially during milking periods or shortly after milking when the teat pores are still open.

Coliforms, pseudomonas and environmental streptococcal, are the major organisms responsible for environmental mastitis but other organisms in the cows environment may also be responsible. How does the cow get environmental mastitis?

Mouth To Udder

Rarely will the cow suck on its teats but what about the calf? Calf suckling risks dairy cows to environmental mastitis as the teat canal tends to open creating an entry point for the bacteria. The common agents of such mastitis include Staph, Strep, aureus and agalactiae. Researc is still ongoing on this type of mastitis which most dairy professionals have termed controversial.

Teat Skin To Udder

This mode of transmission is common with Corynebacterium bovis or Coagulase negative Staphylococci which are considered to be minor pathogens and result in strak canal infections. Though their presence is said to protect the cow against major pathogens, these pathogens may end up harming the cows. Dry cow antibiotic and germinal teat dips will be necessary in the control of the adverse effects of the pathogen.


Summer mastitis caused by Actinomyces pyogens can be transmitted by flies. This is common in heifers and dry cows, Aureus mastitis that occurs just before calving in heifers may also be transmitted by flies from one animal to the other.

Clinical Mastitis

Sub-Clinical Mastitis

This is the form in which the milk and the udder appear normal. Sub-clinical mastitis is difficult to detect and will affect the farmer’s bottom line as it results in lower milk production, suppresses reproductive performance and decreases milk quality. Normally, the estimated milk loss will be 1,500 pounds per cow.

Per Acute Mastitis

This form of mastitis is more severe than sub-clinical mastitis. Mastitis is described as per acute once one or more quarters are gangrenous. Normally, it’s caused by staphylococcus aureus which is a persistent local infection. Here, the signs will be visible and pus will collect creating a botryomycosis effect.

Acute Mastitis

This condition is commonly seen in the postpartum period when bacteria invade the udder and breast through the small erosions in the dairy cow teats. The cow shows signs of pain and the teats and udder will be swollen and hot. The milk too is affected as it contains blood and clots.

Sub Acute Mastitis In Cows

This form of mastitis in dairy cows is associated with staphylococcus aureus. It is characterized by moderate to severe inflammation, decreased milk production of the teats and udder and serous fibrin/milk clots.

Chronic Mastitis

Just as the name suggests, this is the form of mastitis that is severe and can be seen clearly. The affected dairy cows have serous secretions and more than one quarter may e affected.

Detecting Mastitis In Cows

Cow mastitis can be detected using several procedures most of which are scientific and may require sophisticated equipment and is best done by an expert. Here are some of the techniques used to detect mastitis in dairy cows.

Udder Examination

There are routines that should never be dropped by every dairy farmer and palpation and visual examination of the udder top the list. This should be done daily before inserting the clusters and abnormalities noted and investigated immediately. Mastitis is known to result in udder hardness, swelling, pain and heat and should be easy to detect.

Udder examination is a very effective mastitis detection technique but can be unreliable as udder changes are seen at a rather late stage which means that losses will already have been suffered and the recovery process may also take long.

Foremilking Mastitis Detection

Rather than waiting for signs and symptoms of mastitis to manifest in teats and udder, you can always use other advanced techniques such as fore milking to test for early signs of mastitis. The first signs of mastitis are seen in milk and stripping some milk prior milking may give you the information that you need.

The stripped milk will be checked for signs of flecks, clots and change in color. Streps and Staphs are the common organisms responsible for milk changes while E.coli is associated with traw-colored milk. In most cases, you can expect overlaps and further examination will be necessary to determine what other factors may be responsible.

In-Line Filters

For large scale dairy farming, advanced technology is necessary in detection of mastitis as a huge number of cows is milked every other day. In-line filters are some of the advanced techniques used in large farms. These are mastitis detectors fitted in long milk tubes and when checked after every cow is milked can help detect clots or changes in milk color and quality.

They are however linked to reduced milk machine efficiency as they tend to result in restricted air and milk flow. They are also not effective ways of detecting early signs of mastitis in cows as the data collected may not be accurate considering that milk from different cows will pass through the same tubes. They however help in detecting any signs of mastitis initiating a detailed investigation process.


Mastitis in dairy cows changes ions concentration in milk which changes electrical conductivity. These changes will possibly occur 24 to 36 hrs. before any visible signs can develop. It therefore acts to detect mastitis in cows at the very early stages making it a very efficient mastitis detection technique.

To measure a cow’s milk conductivity, you will need a conductivity meter that can either be an inline or cow side meter. These meters will come in handy in determining every cow’s conductivity. It is important to note that different cows have different conductivities and this requires one to undertake several tests on a particular cow to point out changes. Moreover, these tests should be done on separate quarters as a change in one quarter may be swamped by the lack of change in the other quarters if tested together.

The need to conduct four tests for every cow’s means that a lot of tests need to be done for the entire farm and this definitely demands a dedicated program to handle and interpret the data. It is thus advisable that farmers engage professionals when engaging in such complicated tests.

California Milk Test/California Mastitis Test

This is a more advanced approach that has proved to be worth every farmer’s time and investment. It is the simple indicator of SCC (Somatic Cell Count)present in milk samples. It is a simple but very effective way of detecting subclinical mastitis as it gives immediate results and has no limitations as to who can use it. To undertake this test, you will need to have a CMT test kit which is easily accessible.

Here Are The Crucial Steps To Be Followed In A California Milk Test

  • Clean the cow’s teats and udder thoroughly. Discharge the three to four squirts from each quarter to the ground. Use the paddle to collect two or three squirts of each quarter in individual wells and ensure that the milk doesn’t mix. Hold the paddle vertically to ensure that the excess milk pours out.
  • Add the reagent to the milk. The reagent should be of an equal proportion to the milk. Gently swirl the paddle for 10 seconds to mix the milk and the reagent.
  • Be on the lookout for the constituency of the mixture and not the color. Monitor and record the gel reaction ranging from none to solidified.

Treatment Of Mastitis In Dairy Cattle

Mastitis treatment depends on the type and severity of the infection. Basically, there are two reasons why farmers seek mastitis treatment for dairy cows which are;

  • Returning milk production to normal with acceptable cell count
  • Eradicating the mastitis bacteria

Well, it is way easier getting back to the desired milk standards than getting rid of the bacteria. Mastitis bacteria are stubborn and will require dedicated efforts to eradicate. You see, many people have treated mild mastitis through therapy where the affected quarter is massaged and hand stripped but this doesn’t mean that the mastitis is gone completely as the bacteria will still be there. The same case applies for short course antibiotic treatment.

How To Treat Mastitis In Cows Using Antibiotics

Treating cow mastitis with the use of antibiotics is the most common treatment regime. It gives the farmer the option of going for systematic antibiotics, intramammary antibiotics or the classic mastitis tube depending on the subcutaneous or intramuscular route.

If cows show signs of mild mastitis in a single quarter, intramammary antibiotics should be preferred. If more than one quarter has been affected, systematic antibiotics should be used especially when the udder shows significant changes and the cow shows signs of illness. In some cases, a combination of intramammary antibiotics, systematic antibiotics and therapy may be necessary.

Non Steroidals (NSAIDs)

Non Steroidals are drugs that give the same relief as asprin and are used as pain killers and in the reduction of inflammation. These antibiotics are commonly used in severe cases of mastitis with evidence showing low usefulness in mild cases.

Oxytocin Treatment

Have you wondered why some mastitis bacteria will not leave even with constant use of antibiotics? Well, nourishment may be the answer. The bacteria thrive on the nourishment it gets from the milk.

Therefore, you need to ensure that you are starving them by removing all the milk from the udder and teats. This is achieved by increasing the milking sessions or stripping between milking sessions. If the cow has high milk yields, you may need to inject oxytocin which stimulates milk let down. This will enhance the recovery rate.

Intramammary Infusions

This method ensures that the antibiotic in use gets to the teat cisterns. Some decades ago, full insertion where the cannula was inserted completely was practiced but this has been replaced by partial insertion. In partial insertion, the cannula is inserted halfway into the streak canal allowing the antibiotics to be expelled into the streak canal. The antibiotics are then moved to the cistern by palpating the teats.

What Results In Treatment Failure?

It’s not every time that the cow will show signs of recovering from a mastitis infection. In fact, the cow’s condition may deteriorate with time and here are some of the reasons why this may happen.

  • Treating the wrong cow. This happens at the early stages when the signs aren’t clearly visible. If the tests aren’t accurate, the wrong cow may be treated resulting in health deterioration for the affected cow.
  • Wrong antibiotic. Different antibiotics will treat different types of mastitis. This being the case, getting the right antibiotics for the specific type of mastitis is paramount. If need be, consult a professional.
  • Insufficient treatment. Mastitis in cows needs to be monitored keenly even after antibiotics have been administered. Although the bacteria will be killed, not all and continuous treatment will be necessary.
  • Re-Infection. This is common with environmental mastitis. If nothing i done to eliminate the bacteria from the environment, the cow will definitely be re-infected.

Prevention And Control Of Mastitis In Dairy Cows

Mastitis is not only costly to treat but also results in huge losses. It therefore would be better preventing than treating. There are a number of mastitis prevention and control programs aimed at identifying causative agents, preventing transmission and sharing knowledge on microbial habitats, germicides, milk machine use, mammary defense techniques, microbial virulence factors and mammary physiology and anatomy. These programs will come in handy in helping you control mastitis in the farm.

Controlling Environmental Mastitis

Controlling pathogens in the cow’s environment is not as easy as it may sound. Keeping in mind that there is so much to consider, this is an exercise that will not be accomplished in a day.

It actually demands daily exercises aimed are ensuring that the environment is free from any contamination. Right from beddings to cleaning towels, every aspect of the environment needs to be given utmost attention. Here is a list of things that should be done on a daily basis;

  • Clean the parlor and milk machines
  • Dip teats in germicide after milking session
  • Have disposable towels and only use a towel on an individual cow. If you are using cleaning towels, each cow should have its towel and the towels should be cleaned and stored separately. Preferably use hot water to clean them and leave them to dry in the open.
  • When performing sterilization and udder cleaning, use single dose infusions. This helps avoid cross contamination.
  • Let the cow remain standing at least one hour after milking. This ensures that the teat canals are closed. Having feeds after milking will play the trick.
  • A clean udder may be maintained by clipping the udder as this reduces the chances of dangling dirt.
  • New cows should be isolated and monitored to avoid the introduction of mastitis bacteria.
  • Cull chronically ill animals as this is more economical and reduces the risk of new infections.
  • In case of Pseudomonas contamination, replace heaters and milk machine pipes.

Controlling Contagious Mastitis

This form of mastitis is considered to be easier to control than environmental mastitis. Contagious mastitis can be controlled through teat dipping and the use of antibiotics. Dipping stands out as the easiest control method and should be done after ever milking. At the end of lactation, dry cow antibiotics should be used for every quarter.

If you are having a cow with contagious mastitis, ensure that you are milking it last. This helps lower the risk of infecting other animals. After the milking session, flush out the claws with hot water and germicides. Milking towels should also be washed with hot water and left to air dry.

In some cases teats will have lesions resulting from frostbite, lacerations, chapping or machine damage. Ensure that these lesions are treated and highest hygiene standards are maintained.

If you notice S. aureus in heifers during gestation, administer dry cow antibiotics.

Vaccination For Cow Mastitis

As farmers work on ways of controlling mastitis, scientists have also been working on potential mastitis control vaccines. The efforts have been very fruitful towards coliform mastitis control where mutant gram negative vaccines have been developed.

Efforts have also been directed towards Staphylococcus aureus control with vaccines from protein A which are injected intramuscularly being developed.

Though vaccines have not been successful in controlling mastitis in cows, they have played a vital role in improving cure rates and reducing infection severity. Vaccines result in increased leukocytes in the mammary glands which boosts the cow’s immunity.


Mastitis ranks among some of the deadliest dairy cow diseases. It has left numerous farmers counting losses. Once the bacteria enter a farm, they can become the genesis of huge losses. In extreme cases, they may wipe out the entire herd.

Mastitis is an immune response to bacterial infections which may result from contaminated teat dips, chemicals, and thermal injury, mechanical or environmental factors. It is a multifactorial disease that needs to be closely investigated and examined before it gets out of hand.

If proper measures are taken, mastitis can be controlled and the costs of treating and control will be low. We may not have covered everything about mastitis, its treatment and control but we believe that we have shed some light.

You may need to engage a veterinary just to be sure that you are free from the bacteria. Always strive towards achieving a mastitis free dairy farm.