Animal Health & Disease Management



Local names: 
Luo: Tuo thuno / Embu: yele / Borana & Gabbra:hiha goru, butha / Kamba: Uwau wa nondo, mukamo / Kipsigis: miatapkinai / Maragoli:lifuuti / Somali: candho-barar, canda-barar, carar, galleh, goof / Turkana: loebeta / Kikuyu: Murimu wa nyondo, kuruara mukamo / Maasai: Enkeeya Ollki / Kiswahili: matiti
Common names: 
mammitis, mammite (French), inflammation de la ubres (Spanish) 
Management disease 


Mastitis is inflammation of the udder, the udder is also called mammary gland. Mastitis is mainly a problem in dairy cows but sometimes acute mastitis can also be a problem in dairy goats. However mastitis can affect all milk producing animals as well as humans.
Most mastitis cases result in relatively mild or undetectable inflammation of the udder; called subclinical mastitis. This form of mastitis can persist for the whole life of the cow. The milk gland tissue first hardens and is then slowly destroyed, which can take several lactations until the udder or quarter stops to produce milk at all. The persistent infection in the udder affects the quantity and the quality of the secreted milk. Subclinical mastitis can reduce the milk yield by 40% ! It also spoils the milk quality resulting in rejection of the milk by milk collectors and milk consumers. - All dairy herds have cows with Sub-clinical Mastitis. The percentage of cows infected with subclinical mastitis can be as high as 755.

Seldom occurring but more severe cases of mastitis lead to painful swelling of the affected quarter, abnormal milk, total loss of milk yield or even more severe illness and even death; this form is called clinical mastitis.

A cow with two lost teats from mastitis

© W. Ayako, KARI Naivasha



Causes of mastitis

Mastitis is caused by different bacteria (especially Streptococci, Staphylococci and bacteria originating from the gut, such as E.coli) and is contagious. The bacteria invade the udder through the teat canal.
The most important reservoir of mastitis bacteria is the infected udder. Transmission occurs at milking via the milkers' hands or via the milking equipment.
The infection can spread from one teat/quarter to another and from one animal to another: 
  • Via the hands of the person milking 
  • Through milking bucket and cloth
  • Via flies
  • Via the liners of the milking cup (if milking machine is used) 
  • Via the mouth of the suckling young (esp. kids)
  • Through environmental contamination of the stable or the boma (wet and dirty beddings
  • Through contaminated water 
  • Via contaminated teat dips 
  • Via intra-mammary infusions 
  • Teat skin lesions and wounds 
  • Heifers can become infected with mastitis prior to calving, especially if there a lot of flies. 


The risk of a cow being affected by mastitis increases with the level of milk production. Factors that increase the risk of mastitis are:
  • Early lactation, when animals give a lot of milk 
  • High milk yield 
  • Abnormal teats, the shape of the teat play an important part, as do the presence of wounds on the skin of the teat, especially if they are near the opening 
  • Lack of hygiene in the milking parlor and during milking 
  • Adult cattle are most at risk than young ones and can be infected when lactating or during dry period 


Pigs sometimes get mastitis immediately after giving birth when the piglets are very young.
Trauma and injury during milking or during fighting between cattle can damage the teat !!!
Mycoplasma are special bacteria, which may spread from cow to cow through the air. They infect the body of the animal and then invade the udder via the blood. This is a very specific infection which infects all cattle, causes mastitis, respiratory disease, abortions and makes the whole herd unproductive.
Sheep and goats can also get a very severe form of mastitis called Contagious Agalactia, caused by another type of mycoplasma, which has similar devastating effect on the goat herd (mastitis, arthritis, abortion, septicemia) as the other mycoplasma in cattle.


Signs of Mastitis

Sub-clinical Mastitis ( "invisible mastitis" because it has almost no visible signs)

  • This form of mastitis can persist for the entire lactation and even for the entire life of the cow. Persistent infection of the udder can reduce the milk yield by up to 40%!
  • Sometimes small changes in the milk can be detected, small particles are visible in the milk using a strip cup. 
  • Detection is possible by laboratory examination of the milk to identify the pathogen and also identify the best drug for treatment. Because this mastitis persist for a long time information from the lab can be very useful for the treatment. 
  • The most efficient way to detect sub-clinical Mastitis is by testing the milk using the California Mastitis Test (CMT), which can be done on the farm. After mixing equal volumes of milk and CMT fluid in the paddle the milk from infected quarters will show higher viscosity (be thicker) than the milk from normal quarters. Testing must be done before milking. 

Mild Clinical Mastitis

Agalactic mastitis

© John B. Bashiruddin



The affected quarter(s) may be slightly swollen and a bit painful (cow rejecting the milking!) 

  • The udder should be palpated following milking to detect abnormal changes, look at the udder both before and after milking
  • Changes in the milk are visible using the black plate in the strip-cup; the milk can be watery, have abnormal color (pinkish or yellowish or containing blood), there may also be flakes or clots in the milk 
  • This form of mastitis can be life-threatening in dairy cows and also in dairy goats
  • Swelling and pain in the affected quarter are very strong; the udder is hot, swollen and painful
  • The milk is extremely abnormal: milk becomes thin, watery, yellowish or grey, sometimes with blood clots, milk flow may stop completely
  • The cow (goat) stops to feed and is very sick
In dairy cows this form of severe mastitis is caused by fecal bacteria from the gut (e.g. E. coli). There is severe illness affecting the entire body, loss of appetite, depression, toxemia (blood poisoning), septicemia (bacteria in the blood). The cow may not be able to stand up and death is possible within a few days. - A similar mastitis in dairy goats can be caused by Staphylococcus (a bacterium normally causing wound infections and pus).
Mastitis during the dry period can be especially serious, sometimes leading to complete loss of udder tissue and abscess formation. There is also a form of mastitis which starts during dry period but becomes visible immediately after calving. The milk appears like pus, looks green or yellow-green and have a foul smell (this can also happen in first calving heifers) and cause blockage of the teat canal
Milk samples comparison for agalactic mastitis

© John B. Bashiruddin



Prevention - Treatment

Subclinical mastitis is difficult and expensive to treat. Infections often persist despite treatment. Also wrong application of intra-mammary tubes can introduce more dangerous pathogens into the udder than the ones already present. For example fungi can be introduced into the udder by dirty or repeatedly used intra-mammary tubes and can cause life threatening mastitis which is impossible to treat. Intra-mammary tubes must be stored in a very clean place; once the cap has been removed from the tube it must be used immediately. Contents of one tube treat only one teat - always use one complete intra-mammary tube for one teat, don't split the same tube between two teats.
A farmer checking for mastitis

© William Ayako, Kari Naivasha



Strip cup for testing mastitis

© William Ayako, Kari Naivasha



California mastitis tester

© William Ayako, Kari Naivasha



Drawing milk from different teats on a CMT to test for mastitis

© William Ayako, Kari Naivasha



The importance of strict milking hygiene

The most important is to prevent infection of the udder with mastitis bacteria. This can be done by applying strict milking hygiene:
  • Milk in a clean environment (no flies!); areas around dairy shed must be dry and free of mud and standing water 
  • Where machine milking is practiced a footbath with disinfectant should always be provided; teat cup linings can cause damage to the teats and must be changed frequently; vacuum of the milking machine must be checked and the machine must be serviced regularly 
  • Milk room hygiene including washing of containers and equipment must be continuous 
  • Use very clean milking equipment
  • Wash and dry the teat before milking; it is simple and safe to dry the teats using tissue paper (toilet roll) for cleaning the teats before milking; udder clothes must be disinfected or boiled and allowed to dry in between milking times - otherwise the cloth becomes a source of infection 
  • Wash hands with soap before milking; clean water mixed with a disinfectant should always be available in the dairy (disinfecting dirt does not work, you have to remove the dirt by washing with soap first, then disinfectthe skin) 
  • Wash teats before milking 
  • Use milking salve to protect the teat skin; hand milking must be gentle and never rough; treat all wounds of the teat or of the udder skin with iodine or healing oil as long as the wound is still fresh 
  • Use the strip cup before each and every milking; first milk squeezed out from each quarter and used to test for mastitis should not be dropped on the floor but should be collected in a separate container with a dairy disinfectant
  • Test your cows with CMT regularly 
  • Use iodine teat dip (contains 1% iodophor or 4% hypochlorite) after milking and change teat dip regularly (the teat dip acts as a barrier and prevents bacteria from entering the teat canal); teat cup must be cleaned and disinfected in between milking times 
  • Milk cows with mastitis last; always milk CMT-negative udders and young cows first, because their udder are less likely to be infected; this prevents spread of mastitis from one cow to another 
  • For high yielding cows during early lactation milking three times a day is recommended
  • Old cows with chronic mastitis and abnormal teats and cows with persistent mastitis should not be treated but culled


Dry Cow Therapy is more efficient in eliminating subclinical mastitis than treatment during lactation because in the dry period the drug can act for much longer inside the udder. Consult your veterinarian.
How to apply intra-mammary tubes (example: for dry cow therapy) correctly into the teat.
Step 1: Milk the udder until it is completely empty
Step 2: Clean and dry the end of the teat
Step 3: Apply disinfectant to the tip of the teat 
Step 4: Put the nozzle of the tube into the teat and squeeze the content up into the teat
Step 5: Massage the teat upward
After using intra-mammary tubes the milk contains antibiotics and must not be used for human consumption. Observe the withdrawal period which is given by the manufacturer on the intra-mammary tubes.
Multi ject tubes for treatment of mastitis

© William Ayako, Kari Naivasha



A cow with mastitis undergoing treatment

© William Ayako, Kari Naivasha



The most damaging and persistent pathogen causing subclinical mastitis is Streptococcus agalactiae. It is also the only mastitis pathogen that can be eradicated from a herd. If a laboratory has identified this pathogen in your milk you should consult a veterinarian to make a control plan.

Acute or Severe Clinical Mastitis

Treatment of acute severe mastitis is a race against time. Urgent treatment is required and the services of a veterinarian should be sought immediately. Acute or severe mastitis requires intensive intramuscular and intravenous treatment: antibiotics combined with supportive treatments in the form of fluids (Glucose, electrolytes) and anti-inflammatory drugs are required to save not only the affected quarter but also the cow?s life. While you wait for the veterinarian to arrive empty the affected quarter repeatedly to remove as much liquid, which is full of toxin, as possible. You can also try to cool the affected quarter to reduce the swelling.

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